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Sleep Disturbances and Psychological Functioning in Respiratory Diseases Daljinder Ritu Virk January 2010 The thesis is submitted in partial fulfilment of the requirements for the award of the degree of Doctor of Philosophy of the University of Portsmouth. Declaration No portion of the work referred to in this thesis has been submitted in support of an application of another degree or qualification of this or any other academic or professional institution. 2 Abstract The aims of the present research were to describe in more detail than in previous investigations the occurrence and nature of self reported sleep problems and behaviours in individuals diagnosed with respiratory diseases compared to matched healthy controls and to investigate the psychological associations of these sleep problems. The prevalence and range of sleep disorders was investigated using the Basic Nordic Sleep Questionnaire (BNSQ). Individuals diagnosed with respiratory diseases, included those with asthma (n=46), Chronic Obstructive Respiratory Disease (COPD) (n=18), bronchiectasis (n=16) and asbestosis and related conditions (n=11) and these were compared with healthy matched controls. Individuals with respiratory diseases were recruited from the Queen Alexandra out-patients Respiratory Service at Portsmouth Hospitals National Health Service Trust. Healthy matched controls were recruited through various sources including University of Portsmouth, Queen Alexandra Hospital and Portsmouth City Council staff. Overall individuals diagnosed with asthma, COPD, bronchiectasis and asbestosis and related conditions showed a significantly greater number of self reported sleep problems and behaviours than the healthy controls. A range of sleep problems and behaviours were found in the four respiratory disease groups. These were in many of the categories of sleep disorders as defined by the International Classification of Sleep Disorders-2 (2005): disorders of initiating and maintaining sleep, features associated with sleep disordered breathing, other disorders/behaviours occurring during the sleep and sleep related disorders/behaviours occurring during the day. Psychological functioning was assessed including quality of life, mental health and cognitive functioning using validated psychometric assessments. Many significant differences were found between the individuals with respiratory disease and their healthy controls on these measures. Significant associations were found between the sleep disorders and behaviours and measures of psychological functioning. 3 Contents Declaration 2 Abstract 3 Contents 4-6 List of Figures and Tables 7-9 Abbreviations 10-11 Acknowledgements 12 Dissemination 13 Dedication 14 1 Introduction and outline of the thesis 15-16 2 Literature review 17 2.1 Sleep 2.1.1 Theories of sleep 2.1.2 Physiology of sleep 2.1.3 The classification of sleep disorders 2.1.4 Sleep disorders 2.1.5 Assessments of sleep disorders 2.1.6 Treatments for sleep disorders 2.2 Respiratory Diseases 2.2.1 Asthma 2.2.2 Chronic obstructive respiratory disease 2.2.3 Bronchiectasis 2.2.4 Asbestos related conditions 17-35 36-42 43-47 48-64 65-77 78-84 85-86 87-94 95-103 104-108 109-113 2.3 Studies investigating disturbed sleep and psychological well-being in patients diagnosed with respiratory diseases 2.3.1 Sleep studies of respiratory diseases 2.3.2 Psychological studies of respiratory diseases 2.3.3 Psychological functioning in individuals diagnosed with obstructive sleep apnoea syndrome 114-124 125-132 133-136 2.4 Need and requirements for further research in individuals living with respiratory diseases concerning their sleep and psychological functioning 137-138 4 3 A Cross-sectional survey of sleep disturbance and psychological functioning in individuals with respiratory diseases and matched healthy controls 141 3.1 Aims 3.2 Method 3.2.1 Design 3.2.2 Procedure 3.2.3 Participant recruitment 3.2.4 Assessments 3.2.5 Ethical Approval 3.2.6 Data analysis 142 142-143 144-146 146-150 150 150 3.3 Results 3.3.1 Demographic characteristics 3.3.2 Sleep disorders and behaviours 3.3.3 Daytime sleepiness 3.3.4 Quality of Life 3.3.5 General Health Questionnaire-12 (GHQ-12) 3.3.6 Beck Depression inventory (BDI) 3.3.7 Cognitive assessments 3.3.8 Associations between sleep disorders and behaviours, daytime sleepiness, quality of life, mental health, depression and cognitive functioning 151-159 160-170 171-172 173-178 179-182 183-185 186-191 192-200 201-202 3.4 Summary 5 4 Discussion 203-224 204-207 4.1 Summary 4.2 Main findings and comparison with other studies 207-218 4.3 Evaluation of methodology used and suggestions for refinements in further studies 218-220 4.4 Feasibility 221 4.5 Future research 221-224 References 225-243 Appendices 244 6 List of Tables and Figures Table 2. 1. Differences in physiological characteristics of NREM and REM in male human sleep..........................................................................................................39 Table 2. 2. Terms synonymous with REM and NREM sleep...............................39 Table 3. 1. Total number of individuals diagnosed with respiratory diseases and healthy matched controls recruited...........................................................................144 Table 3 2. Exclusion and inclusion criteria for selecting individuals………….145 Table 3. 3. General characteristics of all groups. .....................................................151 Table 3. 4. Breakdown of ethnic groups across individuals diagnosed with respiratory diseases and healthy controls ...................................................................................152 Table 3. 5. Social economic status across all groups. ..............................................153 Table 3. 6. Breakdown of educational qualifications across the groups. .................154 Table 3. 7. Current illnesses or physical disorder that individuals diagnosed with respiratory diseases and healthy controls have at present or have had in the last 3 months. .....................................................................................................................155 Table 3. 8. Any illness or physical disorder that participants have ever had. ..........157 Table 3. 9. Sleep disturbances in other family members as reported by individuals diagnosed with respiratory diseases and healthy controls........................................158 Table 3. 10. Mean scores obtained in individuals diagnosed with asthma and healthy controls. ....................................................................................................................160 Table 3. 11. Mean time required for sleep and sleep duration as reported by participants within the asthma group........................................................................161 Table 3. 12. Mean scores obtained in individuals diagnosed with COPD and healthy controls. ....................................................................................................................162 Table 3. 13. Mean time required for sleep and sleep duration as reported by participants within the COPD group. .......................................................................163 Table 3. 14. Mean scores obtained in individuals diagnosed with bronchiectasis and healthy controls. .......................................................................................................164 Table 3. 15. Mean time required for sleep and sleep duration as reported by participants within the bronchiectasis group. ...........................................................165 Table 3. 16. Mean scores obtained in individuals diagnosed with asbestosis related conditions and healthy controls................................................................................166 Table 3. 17. Mean time required for sleep and sleep duration as reported by participants within the asbestosis & related conditions group .................................167 Table 3. 18. Mean Epworth Sleepiness Score in individuals diagnosed with asthma and healthy controls..................................................................................................170 Table 3. 19. Mean Epworth Sleepiness Score in individuals diagnosed with COPD and healthy controls..................................................................................................170 Table 3. 20. Mean Epworth Sleepiness Score in individuals diagnosed with bronchiectasis and healthy controls..........................................................................171 Table 3. 21. Mean Epworth Sleepiness Score in individual diagnosed with asbestosis related conditions and healthy controls. ...................................................................171 Table 3. 22. Mean SF-36 scores in the group with asthma. .....................................173 Table 3. 23. Mean SF-36 scores in the group with COPD.......................................174 Table 3. 24. Mean SF-36 scores in the group with bronchiectasis...........................175 Table 3. 25. Mean SF-36 scores in the group with asbestosis related conditions.......... ..................................................................................................................................176 7 Table 3. 26. Mean GHQ-12 scores in the group with asthma ..................................178 Table 3. 27. Mean GHQ-12 scores in the group with COPD...................................179 Table 3. 28. Mean GHQ-12 scores in the group with bronchiectasis ......................179 Table 3. 29. Mean GHQ-12 scores in the group with asbestosis related conditions.. .. ..................................................................................................................................180 Table 3. 30. Global BDI-II scores in the group with asthma ...................................182 Table 3. 31. Global BDI-II scores in the group with COPD ....................................183 Table 3. 32. Global BDI-II scores in the group with bronchiectasis........................183 Table 3. 33. Global BDI-II scores in the group with asbestosis related conditions ...... ..................................................................................................................................184 Table 3. 34. Mean Item 1 scores in the group with asthma......................................186 Table 3. 35. Mean Item 1 scores in the group with COPD ......................................186 Table 3. 36. Mean Item 1 scores in the group with bronchiectasis ..........................187 Table 3. 37. Mean Item 1 scores in the group with asbestosis related conditions ........ ..................................................................................................................................187 Table 3. 38. Mean Item 2 scores in the group with asthma......................................188 Table 3. 39. Mean Item 2 scores in the group with COPD ......................................188 Table 3. 40. Mean Item 2 scores in the group with bronchiectasis ..........................189 Table 3. 41. Mean Item 2 scores in the group with asbestosis related conditions ........ ..................................................................................................................................189 Table 3. 42. Pearson Correlation Coefficients for the Disorders of Initiating and Maintaining Sleep (DIMS), Sleep Disordered Breathing (SDB), other disorders during sleep, and other disorders during the day and Epworth Sleepiness score (ESS), general Health Questionnaire (GHQ-12), physical component score (PCS) and mental component scpre (MCS), Beck Depression Inventory (BDI) score and cognitive functioning global score (COG) ...............................................................192 Table 3. 43. Pearson Correlation Coefficients for the Disorders of Initiating and Maintaining Sleep (DIMS), Sleep Disordered Breathing (SDB), other disorders during sleep, and other disorders during the day and Epworth Sleepiness score (ESS), general Health Questio nnaire (GHQ-12), physical component score (PCS) and mental component scpre (MCS), Beck Depression Inventory (BDI) score and cognitive functioning global score (COG) ...............................................................194 Table 3. 44. Pearson Correlation Coefficients for the Disorders of Initiating and Maintaining Sleep (DIMS), Sleep Disordered Breathing (SDB), other disorders during sleep, and other disorders during the day and Epworth Sleepiness score (ESS), general Health Question nnaire (GHQ-12), physical component score (PCS) and mental component scpre (MCS), Beck Depression Inventory (BDI) score and cognitive functioning global score (COG) ...............................................................195 Table 3. 45. Pearson Correlation Coefficients for the Disorders of Initiating and Maintaining Sleep (DIMS), Sleep Disordered Breathing (SDB), other disorders during sleep, and other disorders during the day and Epworth Sleepiness score (ESS), general Health Question nnaire (GHQ-12), physical component score (PCS) and mental component scpre (MCS), Beck Depression Inventory (BDI) score and cognitive functioning global score (COG) ...............................................................197 8 Figure 2. 1. Examples of waveforms that differentiate sleep stages.........................40 Figure 2. 2. The progression of sleep stages across a single night sleep in a normal adult.......................................................................................................................41 9 Acronyms and Abbreviations AASM-American Academy of Sleep Medicine ACQ-Asthma Control Questionnaire AD-Alzheimer’s Disease ANS-Autonomic Nervous System AQLQ-Asthma Quality of life Questionnaire ATP- Adenosine Triphosphate ATS-American Thoracic Society BMI-Body Mass Index BNSQ-Basic Nordic Sleep Questionnaire BTS-British Thoracic Society CABG-Coronary Artery Bypass Grafting CNS-Central Nervous System COPD-Chronic Obstructive Pulmonary Disease CPAP-Continuous Positive Airway Pressure CT-Computerised Tomography DIMS-Disorders of Initiating and Maintaining Sleep DQS-Deep Quiet Sleep DSM-IV-TR-Diagnostic and Statistical Manual-IV-Text Revision ECT-Electroconvulsive Therapy EDS-Excessive Daytime Sleepiness ER-Emergency Room ESS-Epworth Sleepiness Scale FEV1-Forced Expiratory Volume in 1 second FEV-Forced Expiratory Volume FVC-Forced Vital capacity GHQ-General Health Questionnaire GP-General Practitioner HRQoL-Health Related Quality of Life. ICD-9-CM-International Classification of Diseases-9-Clinical Modification ICD-International Classification of Diseases ICSD-International Classification of Sleep Disorders IgE-Immunoglobin class E LED-Light Emitting Diode LH-Luteinizing Hormone LQS-Light Quiet Sleep LRT-Lower Respiratory Tract Infection Mini AQLQ-Mini Asthma Quality of Life Questionnaire MOS-Medical Outcome Study MSLT-Multiple Sleep Latency Test NDE-Non Demented Elderly NHS-National Health Service NOS-Not Otherwise Specified NREM-Non Rapid Eye Movement O2-Oxygen OSA-Obstructive Sleep Apnoea OSLER-Oxford Sleep Resistance PCO2 Partial Pressure of Carbon Dioxide 10 PEF-Peak Expiratory Flow PH-Power of Hydrogen PM-Post Meridian PO2-Partial Pressure of Oxygen POMS-Profile Of Mood States PSQI-Pittsburgh Sleep Quality Index QoL-Quality of Life REM-Rapid Eye Movement RLS-Restless Legs Syndrome RMMA- Rhythmic Masticatory Muscle Activity SAHS-Sleep Apnoea-Hypopnoea Syndrome SCL-90-Symptom Checklist-90 SDB-Sleep Disordered Breathing SGRQ-St Georges Respiratory Questionnaire SOREMP- Sleep Onset Rapid Eye Movement Period SRBD-Sleep Related breathing Disorders SRED-Sleep Related Eating Disorder SSRI’S- Selective Serotonin Reuptake Inhibitors SSS-Stanford Sleepiness Scale SWS-Slow Wave Sleep TCA-Tricyclic antidepressants TIB-Time In Bed TLC-Total Lung Capacity UK-United Kingdom UPP- Uvulopalatopharyngoplasty URT-Upper Respiratory Tract Infection vs.-versus α1-Antitrypsin β2-beta 2 11 Acknowledgements I would firstly like to thank my parents and my grandparents for their tremendous support throughout my academic career, their words of encouragement, their emotional support and believing in me. I would especially like to thank my sister Aman for the tremendous support she has offered me throughout this PhD. I would also like to say a big thank you to my dear friends Alex Assimwe and Heather Mackenzie. I am also eternally grateful to Dr Anthony Fallone, Alison Hadley, Dr Andrew Sherley-Dale. I would like to acknowledge all the patients based at Queen Alexandra hospital without whom this PhD would not have been possible. I am also grateful to staff at Portsmouth City Council, my friends, family and colleagues who completed my study questionnaire. I would like to acknowledge the staff based at the respiratory department at Queen Alexandra hospital especially Sue Kerley. They have been very patient and supportive whilst I was recruiting participants from the clinics. I would like to extend this acknowledgement to Simon Charter in designing the study questionnaire. I would like to thank my director of studies, Dr Rebecca Stores for her tremendous support throughout my PhD. Lastly, thank you to my clinical supervisor, Professor Anoop Chauhan in assisting with the recruitment of patients from the clinics at Queen Alexandra hospital. 12 Dissemination Conference presentations Poster presentation of present study in 2005 and 2006 presented at the following conferences: • The Geographical Health Inequalities Section • The Psychoneuroimmunology Section • The British Psychology Society annual conference • The Southern Allied Health Professions Council annual conference • The Psychological Postgraduate Affairs Group annual conference • The British Medical Association Winter meeting • The British Psychology Society Wessex Branch • The British Psychology Society Postgraduate Student conference 13 Dedication I would like to dedicate this thesis to my late aunt, Iqbal Virk who sadly lost her battle against cancer on December 8th 2009. 14 1 Introduction and outline of the thesis The sleep problems and psychological functioning of individuals diagnosed with respiratory diseases is a much neglected topic despite the fact that there is empirical evidence of such morbidity found in other chronic conditions which are often severe and persistent. Observations have been made about the extent of sleep problems in patients with respiratory diseases. They have highlighted the serious effects of such phenomena on both the individuals health and their well-being, more specifically psychological functioning which incorporates quality of life (QoL), mood, memory and cognitive functioning. The programme of research to be described focuses upon patients diagnosed with asthma, chronic obstructive pulmonary disease (COPD), bronchiectasis and asbestosis and related illnesses. Although these specific groups of patients have received attention in the literature, the details of the self reported sleep problems associated with these conditions have not been appropriately defined and the possible psychological consequences have not been the subject of systematic research. Clearly, such consequences are potentially serious in patients with these respiratory diseases as they may add to the overall level of debilitating effect associated with the conditions. The aims of the present research are to describe, in more detail than previous investigations, the occurrence and nature of self reported sleep problems and behaviours in patients with respiratory diseases compared to healthy matched controls, to investigate their psychological well-being and to explore the psychological associations of sleep disturbances in these individuals. This thesis is divided into four parts: Part (1)-Introduction and outline of the thesis; Part (2)-Literature Review is divided into 4 sections which provide an overview and discussion of the literature most relevant to the present research; Section 2.1 focuses on sleep. Section 2.2 includes separate accounts of the four respiratory diseases that have been investigated within this research, these being asthma, COPD, bronchiectasis and asbestosis. Section 2.3 focuses on a review of past studies investigating disturbed sleep and psychological well-being in individual diagnosed with respiratory diseases, psychological and quality of sleep studies of respiratory diseases, studies employing both objective and subjective methods to investigate 15 disturbed sleep in individual diagnosed with respiratory diseases and finally studies investigating psychological functioning in individuals diagnosed with obstructive sleep apnoea syndrome (OSAS). Section 2.4 is concerned with the need for further research in patients living with respiratory diseases concerning their sleep and psychological functioning. This provides the background and rationale to the present programme of research. Part (3) describes a cross-sectional survey of sleep disturbances and psychological functioning in individuals with respiratory diseases and matched healthy controls. Part (4) is the discussion of the present programme of research. The findings are discussed and compared with previous studies. Limitations and possible refinements are also described along with suggestions for future research. Finally, the references and appendices are presented 16 2 Literature review 2.1 Sleep 2.1.1 Theories of sleep Definition of sleep Sleep is an active physiological state that is characterised by dynamic fluctuations in the central nervous system, (Bae and Foldvary-Schaefer, 2005). The purpose of sleep has not been fully understood, although it is known that sleep is important in memory consolidation and repair (Bae and Foldvary-Schaefer, 2005). Theories of sleep The three main theories of why humans sleep that will be discussed in this chapter are as follows: the restoration theory, the evolutionary theory (or ecological theory) and the neurochemical theory. Each theory will be discussed in turn. Restoration theory Oswald (1970, 1976) suggested that both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep serve the purpose of restoring and replenishing our bodies and brains. (Rapid eye movement and non-rapid eye movement sleep will be discussed in section 2.1.2, physiology of sleep). This supposes that we sleep to restore ourselves physically and psychologically. Oswald (1970) has suggested that non-rapid eye movement (NREM) is important for restoring bodily processes that may have deteriorated or may have been worn down during the day. REM sleep has been described by Oswald (1970) as that which renews brain processes and replenishes neurochemicals used up in the day; these are regenerated by protein synthesis. Evidence that supports the restoration theory Empirical evidence supports Oswald’s restoration theory (Bentley, 1999). Foetuses and babies have been shown to sleep with REM and NREM sleep for a greater proportion of the day than older children or even adults (Bentley, 1999). It is during these earlier stages of development that the body of a developing foetus or a baby 17 grows faster and neural connections are established. An adult will spend on average eight hours in sleep (fewer in old age) whereas newborn babies have been shown to sleep for up to eighteen hours a day. Half of the eighteen hours or so are spent in REM sleep, whereas adults have been shown to spend about a quarter of their sleep in REM (Bentley, 1999). The amount of time spent in REM sleep corresponds to the large amount of activity that occurs in the developing brain, where protein synthesis is required for cell and synaptic growth (Bentley, 1999). Oswald (1980) states that physical repair and brain-protein synthesis are both dependant on growth hormone. Growth hormone is secreted after the first burst of delta activity in slow wave sleep (slow wave sleep is discussed in section 2.1.2, physiology of sleep). Further support for the restoration theory is provided by studies in patients who have incurred damage to their brains from drug overdoses or electroconvulsive therapy (ECT) and who have been shown to spend an increased time in REM sleep (Crick and Hitchinson, 1983). It has been suggested that perhaps patients who have had such damage tend to spend more time in REM sleep so that the brain proteins required can be synthesized (Bentley, 1999). Blood flow to the brain has been shown to increase during REM sleep, most likely required to provide extra oxygen, glucose and nutrients for the protein synthesis (Bentley, 1999). The theories provided here are speculative, the evidence for them yet to be methodically examined. Further evidence from a cognitive psychological perspective emerges from studies of learning, in which REM sleep has been related to learning and consolidation of memory (Loftus, 1997). A study by Bloch (1976) showed that rats that were given complex maze-like tasks every day had an increase in REM sleep. This perhaps shows that learning is related to protein synthesis. Evidence that does not support the restoration theory Extensive research into protein synthesis has shown that amino acids (the building blocks for protein and neurochemicals) are not stored by the body. Since amino acids only last approximately four hours after a meal within the body. It is likely that 18 protein synthesis might be stopped halfway through the night’s sleep because the available amino acids are exhausted (Bentley, 1999). Studies using the sleep deprivation technique have shown that we do not require to make up for lost sleep but we do appear to need REM sleep or core sleep (core sleep is discussed in section 2.1.2, physiology of sleep). If the restoration theory proposes that sleep is required to restore then findings from sleep deprivation studies would be consistent and this is not the case (Bentley, 1999). It has also been proposed that some form of recovery and manufacture of biochemicals may also take place during the day when a person is relaxed (Bentley, 1999). Another factor which further suggests that sleep may not be seen as a restorative period is the lack of experimental support for the supposition that the more active an individual is during the day the more sleep occurs at night. Shapiro et al (1981) recorded the sleep duration of marathon runners after a race; they showed a decrease in REM sleep but showed as well more slow-wave sleep. Further agreement with these results is provided by Horne and Minard (1985) in which participants were engaged in a number of different physical activities but found no increases in sleep, although the participants did go to sleep faster. Carlson (1986) has suggested that perhaps slow-wave sleep is more important for recovery after vigorous activity. An alternative restoration theory Professor David Maurice (1998) proposes an alternative point of view of the restoration theory. Maurice states that REM sleep occurs because during sleep the fluid inside the eyes would not circulate and the eyes might become short of the oxygen supply borne by this fluid. Maurice states that moving the eyeballs creates small currents in this fluid and ensures the delivery of oxygen to the cornea. This does explain why foetuses have REM sleep and why periods of REM sleep become longer in adults as the night progresses. However, this alternative theory by Maurice does not explain why those participants who are experimentally deprived of REM sleep have no eye problems reported (although, for ethical reasons, perhaps this does 19 not go on long enough for damage to become noticeable) and also have a reported increased amount of REM sleep when allowed to sleep naturally. The neurochemical theory The neurochemical approach suggests that sleep has a particular function within the brain, a specialised type of restoration theory (Bentley, 1999). Rapid Eye Movement (REM) Sleep REM sleep appears to be controlled by a noradrenalin pathway going up through the brain. Studies have shown that as a feature of depression, sufferers have unusually large amounts of REM sleep. It has also been found that REM deprivation can relieve depression (Vogel, 1975). This suggests that there is a link between too much REM and depression. Some drugs that are used to treat depression such as the tricyclic antidepressants have also been found to reduce REM sleep (pharmacological aids for treating sleep disorders are discussed in section 2.5.1). Tricyclics work by stimulating the noradrenergic pathways and the production of noradrenalin. Perhaps what the drug is doing is performing the functions of REM sleep and therefore less sleep is needed and, for whatever reason, the reduced REM sleep alleviates depression (Bentley, 1999). Parallel experimental studies have also been performed in non-human species whereby noradrenaline has been reduced in the brain and thus causing an increase REM sleep. Again, this provides support for the association between REM and noradrenaline; REM sleep has a neurological purpose to replenish the brain’s noradrenaline levels that may have been depleted by daily activities (Bentley, 1999). Non Rapid Eye Movement (NREM) Sleep Serotonin, a neurotransmitter, has been shown to be linked with NREM or slowwave sleep. If serotonin is reduced with the use of certain drugs, this has an impact on the amount of NREM sleep, which is also reduced. This suggests that a serotonin dependant pathway is required to have NREM sleep, an assertion supported by studies with depressed patients. Patients with unipolar depression have an inability to fall asleep: they remain tired but awake every night well into the early hours of the 20 morning and once sleep does come it lasts a very short time (Stern, and Morzane, 1974). Once again, successful treatment of depression using selective serotonin reuptake inhibitors (SSRIs) such as Prozac increase the activity of serotonin in the brain, increasing the amount of time the neurotransmitter lingers in the synaptic cleft, restoring both the sleep patterns and the person’s mood. Experiments by Greene at Harvard University suggest that sleep is linked to molecules that appear within all cells. These are the cellular source of energy, what could be called molecular “torch-batteries” (Holmes, 1997). These molecules are called adenosine triphosphate (ATP), made up of adenosine (adenosine plays an important role in biochemical processes, such as energy transfer; it is also an inhibitory neurotransmitter, believed to play a role in promoting sleep and suppressing arousal, with levels increasing with each hour an organism is awake). Adenosine could be the key to why we sleep, as in cats: when adenosine levels rise above a critical level they get sleepy and sleep longer in both REM and NREM sleep. As well, during sleep, levels of adenosine fall, to rise again during wakefulness (Carlson, 1997). This supports the notion that we have NREM sleep in order to be able to go into REM sleep and we therefore need REM sleep to deal with the build up of adenosine. Such a mechanism suggests that sleep is a homeostatic process, to balance various neurochemicals in our body (Bentley, 1999). Finally, Hobson (1995) provides a review of the main theories of sleep and puts forward a three tier analysis: Behaviourally, sleep conserves energy in situations where it may be required for example, when foraging for food or for finding a mate when conditions may likely to be difficult, or when there is a decrease in climatic temperature. This suggests that sleep is favourable in less hospitable conditions. It is also a time for pair-bonded or family groups to strengthen relationships by being together either during the period leading up to sleep as well as when actually sleeping. 21 Developmentally, the brain structures and connections can grow and mature before they are needed in action, this connects with the restoration theory. Metabolically, various physiological changes such as alterations in blood pressure and release of hormones occur during sleep. Experimental studies of sleep deprivation Such experiments have been concerned with various types of sleep deprivation: acute sleep deprivation, chronic sleep deprivation, selective NREM and REM sleep deprivation and fragmentation of sleep caused by arousals. Acute sleep deprivation One of the first published studies of total sleep loss in puppies dates back to 1894 (Manaceine, 1894) and for humans a couple of years later (Patrick and Gilbert, 1896). Manaceine’s observations indicated that sleep loss when prolonged in animals is fatal; this concept was dismissed until recent findings. The work conducted by Patrick and Gilbert included a range of variables that looked at physiological and behavioural measurements and this study remains a model of its kind. Behaviourally, the effect of sleep loss is sleepiness and this can be extracted from the subjective reports such as the multiple sleep latency test (MSLT), or the change on the EEG or in other simpler forms such as looking at the facial expressions of the participant. Factors that determine the impact of sleep loss can be divided into four categories, these being sleep and circadian influences, arousal system influences, subject characteristics and test characteristics. Under the heading of subject characteristics, the impact of sleep loss on a given individual depends on characteristics that each participant brings to the sleep loss situation. For example, age and personality represent differences in physiological or psychological function that may interact with the sleep loss event. Changes within mood include increased sleepiness, fatigue, irritability, usually difficulty in concentrating and disorientation, are commonly reported during periods of sleep loss. Webb and Levy (1984) reported perceptual distortions and hallucinations of a visual nature in 80% of the normal individuals in their study but this also depended on the type of work in which the participants in the study were 22 involved, the visual demands and the length of deprivation. Individuals who have been diagnosed with schizophrenia also display auditory hallucinations but normal individuals who undergo sleep loss may also express schizophrenic behaviour, such as paranoia. A study by Tyler in 1955 reported 2% of three hundred and fifty participants sleep deprived for 112 hours experienced temporary states resembling acute paranoid schizophrenia. Some individuals did have some form of predisposition towards the condition and those that did experienced significant paranoia during sleep loss and the paranoid behaviour tended to become more pronounced during the night, with partial recovery during the day and disappearance after recovery sleep. Patients who have been known to suffer from depression have also been successfully treated through sleep deprivation. Sleep deprivation has proven to be a successful treatment in cases between 40% to 60% of diagnosed patients for the last thirty years or so (Giedke and Schwarzler, 2002). One theory has proposed that sleep deprivation is effective in those patients with high levels of activation or high central noradrenergic activity because it lowers the effects of chronic hyperarousal (WirzJustice and Van den Hoofdakker, 1999); patients did however report feeling tired and having more energy and improved mood. This study shows that there may be other individual differences that contribute toward sleep deprivation. Chronic sleep deprivation Studies of chronic sleep deprivation have observed increased mood disturbance and negative mood states and greater effort to perform and decreased motivation during chronic sleep restriction; however, the significance levels for these reports are small and unimpressive (Lucas, 1975). A few studies have also examined the occurrence of self-reported symptoms during sleep restriction records. A study by Tobler and Borbély (1986) showed how participants in their study reported an increased incidence of blurry vision, eye dryness, itching and aching and also an increase in appetite when participants were gradually restricted in their sleep across six to eight months. A further study by Tobler, Borbély and Groos (1983) showed how frequent headaches were reported by 23 participants who were restricted to four hours in bed compared to those who were allowed eight hours. Selective non rapid eye movement and rapid eye movement sleep deprivation Studies which examine selective stages of sleep deprivation do so by electively eliminating one or more stages of sleep while having minimal impact on the other sleep stages and total sleep time. Originally, such studies were conducted to determine the significance of REM sleep or SWS and so specific experimental awakenings or arousals were experimentally induced at the onset of a particular stage of sleep for one or more night. Earlier experiments conducted to investigate REM sleep determined that selective deprivation of REM sleep accomplished by the awakening technique resulted in increasingly frequent attempts by participants to enter REM sleep. This can be supported by Agnew, Webb and Williams (1967), who showed how those participants who were deprived of REM sleep required seventeen awakenings on the first night, on the fourth night forty two awakenings were needed and sixty eight awakenings were required on the seventh night to maintain REM sleep deprivation. Agnew and colleagues also observed large increases in REM sleep amount when recovery sleep was allowed which was not disturbed. The EEG data from such studies can be easily replicated but the impact of REM sleep deprivation psychologically in terms of function and performance has been difficult to determine (Pearlman, 1982). There are various theories that attempt to describe the function of REM sleep, such as the: • Drive facilitation hypothesis; • Activation synthesis hypothesis; • Catecholamine restoration hypothesis; • Cortical homeostasis hypothesis; • Information-processing hypothesis; 24 • Neural growth promotion hypothesis; • Oculomotor hypothesis; • Protein synthesis hypothesis; • Sentinel hypothesis. There are more. Recent findings have supported the notion that the activation of the brain during REM sleep is associated with memory consolidation, synthesis of new or adaptive information or arrangement of information into an internal association framework. Of the six reviews that have been published since the year 2000, four of the reviews conclude that REM sleep or sleep in itself is significantly involved with memory (Maquet, 2001; Stickgold, Hobson and Fosse, 2001; Smith, 2001; Peigneux, Laureys and Delbeuck, 2001). The remaining two reviews, however, concluded that there was little evidence to support a role for REM sleep in human memory (Siegel, 2001; Vertes and Eastman, 2000). Work by Peigneux, Laureys and Delbeuck (2001) have shown through animal studies that REM sleep increases after learning and that REM sleep deprivation after a task that has been learned decreases retention. Studies in humans, however, have not shown as much support and this could be due to the fact that some of the animal results may have been secondary to stress or another extraneous variable (Siegel, 2001). Although there is not sufficient evidence to support the role of REM sleep in declarative memory, there are recent studies in humans which have found an improvement in perceptual performance after an eight to ten hour training session and when REM sleep was allowed at intervals (Stickgold, Hobson and Fosse, 2001). The findings from this study have led to the hypothesis that perceptual learning, rather than retention of material which has been memorised, is related to REM sleep. Nevertheless, Siegel (2001) states that these findings do not explain why those participants whose REM sleep has been eliminated by the use of monoamine oxidase inhibitors or brainstem injury have no measurable memory deficits. 25 Other studies which have selectively prevented participants from entering stage 4 sleep through continuous arousals have shown that participants would make an increased effort to enter the stage and had stage 4 rebounds when sleep was not disturbed (Agnew et al, 1967). Agnew et al (1967) compared the effects of stage 4 and REM sleep deprivation; they found that participants required five to seven times as many arousals to deprive them of stage 4 sleep than to deprive them of REM sleep during each night when they were being selectively sleep deprived. The recovery nights which followed stage 4 increased only on the first recovery night and REM sleep which was not deprived increased on recovery nights two and three. After the deprivation of REM sleep, REM sleep increased throughout three recovery nights but there was no increase of stage 4 sleep on any recovery night. Sleep fragmentation Bonnet and Arand (2003) examined the relationship between various schedules of sleep fragmentation and residual sleepiness on the following day. They showed that there was a strong relationship between rate of fragmentation and decrease in sleep latency as measured by the MSLT. A further study supported the fact that increased sleepiness after sleep fragmentation was also associated with decreased psychomotor performance on a broad range of tasks with degraded mood (Bonnet, 2005). Another study by Bonnet (1983) showed how performance loss was the same on a vigilance test after sleep fragmentation and total sleep deprivation but less on other problems completed and simple reaction times after sleep fragmentation. Another study by Series, Roy and Marc (1994) demonstrated patients to have a significant increase in apnoea/hypopnoea index and it was found that after both sleep fragmentation and sleep deprivation this increase was actually greater after sleep deprivation. The findings from these studies indicate that there is much in common between highfrequency sleep fragmentation and total sleep deprivation. The restorative function of sleep is severely impaired by high rates of sleep fragmentation. Medical disorders that are exacerbated by sleep include gastro-oesophageal reflux, nocturnal angina and asthma. 26 Sleep-deprivation studies Human participants In 1960 Dement studied eight volunteers who were monitored during their sleep throughout the night and woken every time the volunteers went into REM sleep. The first night the volunteers were woken on average twelve times; by the seventh night this increased to twenty-six times. This was seen as an indication of the vital nature of REM sleep, the need for REM sleep growing stronger the more the participants were deprived of it. Dement reported that the participants exhibited only minor and temporary behaviour changes associated with this loss of REM sleep. Dement had expected there to be disturbed behaviour patterns emerging from volunteers who had been deprived of REM sleep. The final consequences of sleep deprivation are obviously not shown in humans compared to non-humans; this is because human participants in experiments are treated differently to rats or cats (Bentley, 1999). One of the best signs of stress in humans apart from changes in behaviour during sleep deprivation is the increase in the output of certain hormones. Under nonstressful conditions cortisol is released in small amounts throughout the day and has an obvious circadian rhythm. It peaks around the start of wakefulness and troughs at the beginning of a persons’ daily sleep period. Cortisol production helps mammals endure stress especially in helpless situations. In the 1950’s, Dr Hans Selye identified three phases in the cortisol response to stress: alarm, resistance and exhaustion (Selye, 1976). Exhaustion occurred only when many days would have elapsed. Selye’s interpretation is said to be too simple an explanation for what is said to be clearly a complex problem (Horne, 1988). Selye (1976) observed that whilst injury and illness are major causes for the initial alarm response, it will also occur whenever the body is pushed to extremes. On an important note, psychological factors such as “apprehension” and “fear” are also triggers for this hormone (Horne, 1988). Although animals will show an increase in the release of cortisol during sleep deprivation this is not however the case in humans. In other words, humans can be sleepy, irritable and have a great desire to sleep but as long as no harm will come to us and that we can pull out of the situation if necessary then the deprivation will not necessarily be stressful and this is true of experimental conditions, too (Horne, 1988). 27 In terms of lifelike and real-world investigations of sleep deprivation in humans, various military research groups throughout the world mostly using male soldiers and usually referred to as “Sustained Operation” (“SUSOP”) have carried out various experiments. The advantages of studying such a group is that some ethical and safety factors applied to civilian subjects can be put aside and therefore sleep loss of up to three days of continuous battle can be simulated. Such situations also include heavy exercise and food restriction (Horne, 1988). Such experiments, although very useful, do, however, highlight doubts whether the observed effects are due to sleep loss or other factors (Horne, 1988). One of the main criticisms of such studies is that civilian subjects can withdraw from experimental conditions in a laboratory. Soldiers, however, cannot do this easily. The pressure placed on the individual together with the anxiety caused by the need to perform well adds to the stress. On a positive note, the continuous stimulation offered in such conditions will counteract the sleepy state of the soldiers (Horne, 1988). Case studies in sleep deprivation There are three classic case studies in severe sleep deprivation that are well documented and demonstrate various effects of going without sleep for prolonged periods. Gulevich (1966) reported a 17-year old young man, Randy Gardner, who was able to stay awake for 264 hours (11 days). Gardner developed slurred speech and blurred vision-a combination of perceptual and cognitive faults. Gardner mistook some objects for people and showed what have been described as symptoms of mild paranoia: Gardner thought that people were labelling him as stupid because of his cognitive difficulties. However, Gardner did not experience a complete mental breakdown and once he was able to sleep he did so for 15 hours on the first night and made up a total of just one quarter of his lost sleep. Most of this was Stage 4 NREM and REM sleep. What this may indicate is that Stage 4 NREM and REM sleep may 28 be the most important when the body has been deprived of sleep; nevertheless, it does not tell us what the important functions are of these stages. Another case study reported by Dement in 1972 was of a disc jockey named Peter Tripp who stayed awake for 200 hours as a publicity stunt in New York. Quite severe paranoid psychosis appeared to develop, with Tripp reporting having been poisoned by persons unknown. He displayed, too, self-harming behaviour by trying to throw himself under the wheels of the traffic. Dement described how Tripp’s behaviour and personality changed drastically subsequent to being deprived of sleep. Compared to Gardner’s experience of sleep deprivation, the behaviour displayed by Tripp was very different; this could be due, perhaps, to individual differences or from differing expectations, as Tripp may have expected to experience strange experiences and sensations and so on, whereas Gardner may have not (Bentley, 1999). The final case study, which was of a more clinical or pathological nature, was observed by Lugaresi (1986). Lugaresi followed the progress of a 52-year-old man who was unable to sleep. The sudden onset of sleep deprivation happened when the subject turned 52 and as the sleep deprivation continued, the sufferer became more and more exhausted which led to the development of a fatal lung infection. Post mortem analysis revealed lesions in two areas of the thalamus which is linked to sleep and hormonally controls circadian rhythms. The neurones were found to be completely destroyed within this area. It can be deduced from this case study that sleep deprivation alone could have killed this 52-year-old sufferer, however it may be more likely that the sleep deprivation had major effects including increased stress that makes the person more susceptible to infection (Bentley, 1999). What was first described by Lugaresi in 1986 was later (1995) called ‘Fatal Familial Insomnia (FFI)’ and now is known to be an autosomal dominant prion disease, characterized by degeneration of the thalamus and impaired control of the sleep-wake cycle, autonomic and endocrine functions, involving a progressive decrease or complete absence of sleep activity. Case studies such as these, while it is often said that they 29 are difficult to use to support a hypothesis, can be generalised to a theory, if there were a good theory about the nature of sleep. Experimental studies Experimental studies of sleep deprivation take a more gradualist route of studying sleep deprivation rather than doing without it altogether. Webb and Bonnet’s (1978) study of sleep deprivation started with participants being deprived of just 2 hours sleep; at this point the participants reported feeling well, though it was observed that they did fall asleep quickly the following night and then slept for longer. The participants in this experiment were also put on a two-month programme of gradual sleep reduction from an initial eight hours a night sleep down to a final four hours. The participants did not report any adverse effects; nevertheless, this is something that does not indicate that there is an ability to do without sleep if necessary. In conclusion, the actual amount of sleep per night averages out at about seven to eight hours in total but there are individual differences. When making up for lost sleep a need to do so is not shown, just some of it. This is known as the REMrebound effect, as studies have shown that most of the ‘caught-up’ sleep is REM sleep plus the Stage 4 NREM sleep leading into REM. Huber-Weidman (1976) collated an overview of the findings of studies that have investigated sleep deprivation. The symptoms of such deprivation in these studies were more psychological than physiological for people who had been deprived of sleep for a few days. It is also important to notice that that many if not most of the effects were due to REM deprivation alone rather than total sleep deprivation. Research by Gribbin in 1990 suggested an extra and difficult effect, indicating that too much sleep can impair performance and perhaps lead to or be part of psychological disorders. It has been mentioned earlier that increased REM sleep is a feature of many people with depression; tricyclic antidepressants successfully lift this disorder, selectively blocking and reducing REM sleep without interfering with NREM sleep (Gribbin, 1990). Pinel (1993) uses this notion to claim that REM sleep 30 deprivation is not harmful. Speculation by Horne (2006) directs attention to what have been called ‘ponto-geniculo-occipital spikes’ (PGO spikes) or PGO waves, which derive from three brain areas: the Pons, the geniculate thalamus and the occiput. They have been registered on electroencephalographs as coinciding with REM sleep and both are paralleled with twitches of the fingers and toes. Horne (2006) theorises that PGO waves are internally generated to bombard the cortex to simulate exterior stimuli, keeping the brain active while consciousness is ‘switched off’. In babies in utero this stimulation is especially intense. Such random stimulation may cause the brain to try to make sense of it by creating dreams. Evolutionary or ecological theory Meddis (1975, 1979) put forward an explanation for why we sleep, using an evolutionary or ecological perspective. This theory proposes that sleep could be a time of increased safety as animals are immobile and therefore less likely to be noticed by predators. Meddis suggests that it is better to be still when it is too dark to see either food or threats, acting as an advantage for some animals. However, not all species of animals fit the human, primate or mammalian pattern. Those animals that are nocturnal in habit, such as owls, are specialised to see in low light conditions and bats, which are not dependant on light to find food or to be aware of their environment, use sonar mechanisms to find their way around in conditions where humans are without effective sight. Through evolution these species have developed sleep patterns that fit in with their way of life, sleeping during the day in places of safety. Such species’ sleep patterns still agree with evolutionary theory. There are also those species such as lions that have no predators (Lloyd et al., 1984). Lions appear to be relatively happy wherever they choose to sleep and whenever they can. Another type of creature, which does not fit in with the theory, is grazing animals. Cows and antelopes spend a majority of their time grazing in herds. For these animals to remain still in such a wide-open field would pose great danger and therefore not remaining vigilant could be seriously maladaptive. Given this, as they 31 are constantly at serious risk from predators, this lack of sleep would support Meddis’ theory concerning safety; conversely it is known that animals which graze on vegetation gain little nutritional value per kilogram (meat/protein is the highest energy food) and in order to survive such grazing animals must eat virtually continuously over any 24 hour period. If they did not and stopped to sleep they would lack nutrients and energy for the next day (Meddis, 1975). The evolutionary or ecological theory is based upon the concept that when humans lived in a truly wild state, when our distant ancestors were evolving, those who were able to sleep at night survived better as they were less likely to become prey. Energy had been conserved when it was too dark to see and individuals were successfully hidden from predators. It was those groups of people who were able to pass on the characteristic of sleeping through the night who increased the likelihood of survival for their descendents (Meddis, 1979). The evolutionary or ecological theory fails to explain why after sleep deprivation humans sleep longer and fall asleep in daylight. The theory proposes that humans sleep to preserve themselves. If this were the case it would be found that animals that are likely to be attacked would sleep rather little. This is generally found to be true: predators tend to sleep more than those species of animals that are preyed upon (Bentley, 1999). In addition, it is odd that humans sleep and thus leave themselves in a poor defensive state, even if in protective social groups where there are others to act as sentries or night watchmen: 24 hour alertness would clearly enhance survival, while the sentries always need to sleep in daylight hours to regain their lost sleep. Generally, being paralysed and senseless for hours does not seem of any value when animals are faced with various dangers, including predation. It is advantageous being still and quiet in the dark to avoid danger but being essentially unconscious, unaware of one’s surroundings shows only vulnerability (Bentley, 1999). Core sleep Horne (1988) put forward a model, which acted as a bridge between a theory of sleep and sleep-deprivation studies. Horne stated that most people have more sleep than is 32 needed. It has been stated and described, in the restoration theory presented earlier, that people sleep so that their bodies need time to replenish biochemicals that have been used during the day. Horne pointed out that cell restoration is not just limited to what goes on during the night, it occurs during the day, too, suggesting that perhaps only some sleep is necessary, perhaps the early hours. Horne referred to this as being core sleep. Horne bases this concept on an older study where groups of participants were allowed six weeks on a fixed amount of sleep per night. One group of participants slept for four hours nightly, a second group slept for six hours and the third group for seven-and-a-half hours. Participants were also given cognitive tasks to complete before and after the experimental sleep period and only those who were given four hours of sleep showed any deleterious effect on memory. From this Horne concluded that only about five hours of sleep a night are required; any more has been termed as optional sleep and could be omitted without any ill effects. Figure 2.2 shows the progression of sleep stages across a single night’s sleep in a normal human; from this diagram it may be seen that Horne is suggesting that Stage 4 NREM sleep is vital but only about half the average REM sleep is needed (Bentley, 1999). Long-term loss of REM sleep, however, is associated with psychological dysfunctions such as hallucinations or waking dreams, something that does not support Horne’s theorising. This theory as a whole is still basically conjecture and it is difficult to see how empirical evidence could be obtained to support this hypothesis (Horne, 1992). Meddis also suggests that babies tend to sleep longer to prevent exhaustion in their mothers. However this concept does not explain the survival of the non-sleepy trait in babies, nor the variation in quantities and type of sleep in people of all ages. Empson (1989) has described Meddis’ theory as a ‘waste of time’ theory, meaning that it suggests that sleep is a waste of time (Empson, 1989). Empson suggests that sleep is universal among animals; even the most successful predators; sleep deprivation can on occasion be fatal, suggesting that sleep has some value. 33 It has been suggested by Horne that sleep may perform different functions in different species and different sizes of animals, such as aquatic animals, grazing animals and those with higher intellects (Horne, 1988). There are evolutionary principles at work when dolphins appear to develop sleep-adaptations specific to their environment. Sleep must be serving a purpose and each species evolve a means of sleeping in such a way that does not threaten their survival (Horne, 1988). Summary Three of the main theories which propose an explanation for why there is sleep have been described in this chapter: sleep as restoration and an extension of the restoration theory in the neurochemical model of sleep and finally sleep as an evolutionary behaviour. The restoration theory proposed by Oswald suggests that both REM and NREM sleep restore and replenishes our brains and bodies. During sleep neurochemicals are resynthesised and the growth hormone is secreted. There is evidence for and against this theory. Non-human animal studies show mixed support for this theory. Hobson proposes a three-tier analysis of sleep which ties together the models described in this chapter. Research has shown that detrimental effects occur when various species are denied sleep. These effects vary from minor, short-term perceptual problems to major and lasting personality changes. Little is known about the extent that these are specifically caused by total sleep deprivation or REM deprivation. The neurochemical theory, states that sleep has a specialised restorative function in the brain. It has been suggested that REM sleep is associated with a noradrenaline pathway and replenishes noradrenaline levels in the brain. NREM sleep is associated with serotonin levels and might require a critical level of serotonin to be switched on. Sleep is not seen as just one phenomenon but usually several. Sleep can be divided into two main types, this being REM (rapid eye movement) where dreams occur, perhaps under the prodding of PGO waves and NREM (non-rapid eye movement) 34 sleep where the eyes are fairly still and we hardly dream. NREM sleep consists of four stages; each stage is characterised by its own electroencephalographic (EEG) pattern. The last theory described in this chapter, the evolutionary or ecological theory suggests that sleep is a time of inaction so that prey can be safe from predators. Sleep in babies can be explained using the evolutionary theory. There are, however, observations which do not fit this model, Horne attempted to overcome these criticisms by hypothesising that sleep performs different functions in different species. The theories and evidence presented within this section attempts to explain the function of sleep. It can be said that some of the studies do require further investigation and support. It is also, as usual, quite difficult to extend the evidence from animal to human studies. All the evidence, human and animal, also as usual, may be accused of being presented in a rather biased way, according to which particular school of thought it is attempting to support. This falls short of the ideals of the scientific method, is characteristic of swathes of human research in every field but thankfully is not true of all. 35 2.1.2 Physiology of sleep Although sleep is an altered state of consciousness, it is not a state of unconsciousness, meaning that even those who are deep sleepers can still be aroused from their somnolent state. Normal sleep consists of humans sleeping once per day and within this period of sleep humans will experience a number of different states of consciousness. Dement and Kleitman’s sleep medicine work has shown that not only are there two types of sleep but there are, as well, associated brain waves (electroencephalogram-EEG) (EEG is discussed further in section 2.4.2) patterns. These two types of sleep alternate in an ultradian rhythm (meaning less than a day, cycles which occur within a day) and that dreaming is associated much more strongly with one of those types. The two types of sleep being referred to here are rapid eye movement or REM sleep and non-rapid eye movement or NREM sleep, these will be discussed next. Stages of sleep As sleep deepens it goes through four separate stages (Bentley, 1999). Each stage of sleep has its own EEG pattern; there are four stages in NREM sleep (also referred to as quiet sleep). Stage 1 NREM Stage 1 sleep is when sleep begins and this usually takes fifteen minutes. Recordings show brain waves slow down from the alpha waves of relaxation to even slower and more irregular theta waves (see figure 2.1). Once these patterns synchronise, typical characteristics emerge. The parasympathetic nervous system governs this stage; heart rate slows down and muscles relax. Falling asleep may not be a conscious process and is a state very similar to deep meditation and relaxation. During this stage arousal occurs easily and full consciousness can recur quite easily. This first relaxed stage of sleep is also known as the hypnogogic state and some writers link hallucinatory images occurring now to creativity. 36 Stage 2 NREM This stage lasts for approximately twenty minutes, the brain waves get slower and larger with intermittent little bursts of activity called sleep spindles, electrical activity (little is understood in terms of its purpose or function), k-complexes, these are tiny burst of activity which is usually associated with external stimuli which do not awaken us (environmental stimuli). Physiological changes such as a decrease in heart rate, blood pressure and body temperature continue and quieter sounds no longer disturb sleep. Stage 3 NREM There is a further decrease in heart and breathing rate and brain waves slow further and now occur as delta waves. It is usually very difficult to be aroused from this stage; like stage 2 sleep this stage lasts for only a few minutes. Stage 4 NREM This stage is characteristic of the deepest sleep. Metabolic rate is at its lowest and it is very difficult to waken out of this state – usually only a significant noise can arouse the person from this stage, such as a baby crying. Brain waves are usually slow. This stage lasts for thirty to forty minutes and is the bottom of the ‘sleep staircase’ (Bentley, 1999). Although this stage is the deepest stage of quiet sleep, this is the stage at which sleepwalking is likely to occur and is not associated with dreaming (Jacobson and Kales, 1967). Sleep talking also occurs in deep NREM sleep, although this can happen but less often during REM sleep as well (Arkin, 1970). REM sleep including dreaming After half an hour into Stage 4 sleep, the EEG trace speeds up the ‘sleep staircase’ through Stages 3 and 2, thus showing the brain to be suddenly more active, (Bentley, 1999). The once synchronised brain waves become desynchronised and more complex as well as faster; the brains oxygen and glucose demands also increase. The eyes will also start to move rapidly under the closed eyelids, this state is known as REM sleep and the person is most difficult to arouse. 37 Cerebrally there is considerable activity paralleled by physical inactivity; the body will appear almost paralysed. The heart and lungs will match the brain activity even though the body is inactive. REM sleep lasts for about ten to fifteen minutes and this completes the first sleep cycle of the night. Once REM sleep has elapsed then there is progression through Stages 2 to 4 again and this cycle repeats about every ninety minutes throughout the night. As the night continues sleep in Stages 3 and 4 lessens until only Stage 1 and 2 of NREM plus REM sleep are returned to by the end of the night (see figure 2.2). This ninetyminute cycle is the ultradian rhythm of sleep. Recalling a dream often depends on which stage a specific awakening occurs. REM sleep has been called ‘dream sleep’ or the ‘D state’ and some have gone as far as to call it the ‘third state of existence’. Eighty percent of the time, when sleeping volunteers are woken during REM sleep, they’ll report that they have been dreaming. The nature of REM’s reflects the content of the dream. Other terms for REM sleep Dement and Kleitman (1957) made observations and noted that REM sleep is associated with highly active brain activity yet the body is in a paralysed state; actually, this is called ‘atonia’: ‘without movement’, switched on by a part of the brain called the locus ceruleus at the commencement of REM sleep and off when it finishes. Dement and Kleitman coined the term paradoxical sleep to describe this apparent contradiction, the paradox being that the brain is full of activity while the body is inactive. Modern researchers would prefer REM sleep to be renamed as Stage 5 sleep (Bentley, 1999). Meddis (1979) referred to NREM sleep as quiet sleep and REM sleep as active sleep. These terms were coined due to the brain activity shown by the EEG traces. Meddis further subdivided quiet sleep into light quiet sleep (LQS) with synchronised slow patterns of EEG traces and deep quiet sleep (DQS) which is representative of larger, regular wave-like EEG traces. Stage 2 sleep would be seen as light quiet sleep and 38 Stage 4 would be seen as deep quiet sleep. Stage 1 and REM sleep would be seen as Active sleep (AS). Table 2.1 displays the difference in physiological characteristic of NREM and REM sleep in humans and Table 2.2 shows the different terms that are used to describe REM and NREM sleep. Table 2.1: Differences in Physiological Characteristics of NREM and REM in Male Humans at/during Sleep Measurement NREM Sleep REM Sleep Scalp EEG* Slow waves and spindles Low voltage, mixed frequency Hippocampal EEG Variable Rhythmic theta activities Eye movements None or few slow movements Conjugate rapid movements Chin electromyography (EMG)* Decreased from wakefulness Almost absent Body movements A few gross movements Twitches Respiration Regular, deep Variable, shallow Heart rate Regular, slow Variable, rapid Blood pressure Below waking level Variable Penile erection Normally absent Normally present Mentation Thought-like, repetitive Dream-like, dramatic Galvanic skin response Frequent Rare From: Freemon, (1972) Sleep Research: a critical review. Springfield. Table 2.2: Terms Synonymous with REM and NREM Sleep REM NREM Dreaming Paradoxical Fast Active D-sleep Desynchronised Nondreaming Orthodox Slow Quiet S-sleep Synchronised From: Anch et al (1988) Sleep: A Scientific Perspective, Prentice Hall, Englewood Cliffs, New Jersey. 39 Figure 2.1 Examples of waveforms that differentiate sleep stages Cps - cycles per second. From: www.rtmagazine.com/issues/articles accessed 22nd June 2009. 40 Figure 2.2: The progression of sleep stages across a single night sleep in a normal adult. From: http://somnience.com/images/sleep_cycle.jpg accessed June 22nd 2009 41 Summary This section deals with the physiology of sleep. It has highlighted the main stages of sleep, these being, Stage 1 NREM sleep which lasts for fifteen minutes, Stage 2 NREM sleep which lasts for twenty minutes and brain waves get slower and sleep spindles begin to emerge. Stage 3 NREM sleep shows a further decrease in heart and breathing rate leading onto Stage 4 NREM sleep which is also known as deep sleep where only a significant noise can arouse a person from sleep and finally REM sleep and dreaming occurs which occurs thirty minutes into Stage 4 NREM sleep, in this stage the brain has been shown to be more active and a key feature of this stage is that the eyes will also start to move more rapidly under closed eyelids and the person is most difficult to arouse. 42 2.1.3 The classification of sleep disorders Introduction The last 15 years have seen a major advancement in sleep medicine, the ability to diagnose, evaluate and treat disorders of sleep and arousal, leading to the discovery of more than 60 disorders. Sleep disorders are not prevalent in just one particular age group; they affect all ages. Disorders can be mild or life threatening; these advancements would not have been made without improved knowledge of the physiology of sleep, the technological advances which have allowed researchers to measure the physiological variables affecting sleep. Historical background The early 1970’s saw a growing clinical interest in sleep disorders and arousal. As with any common interest, there was a lack of common terminology and diagnostic framework for the various disorders. This showed that there was a need for a classification system that would allow the definition and specification of a disorder. It is important to note that most medical disorders can still be described using the phenomenological method, which looks at the effects on certain body systems as reported by individuals from their subjective experience. Many medical conditions are classified according to the cause of the disease; such disorders are described as being infectious, metabolic, neoplastic, and traumatic. The aetiology of sleep and its disorders remains unknown, thus resulting in the clinician relying upon the phenomenological method rather than the aetiological classification of sleep disorders. Diagnostic Classification of Sleep and Arousal Disorders (1979) 1979 saw the development of the Diagnostic Classification of Sleep and Arousal Disorders (DCSAD) by The Association of Sleep Disorders Centers (ASDC) and the Association for the Psychophysiological Study of Sleep (APSS). It was important for the committee members to produce a diagnostic criterion that had validity and was standardised too. The production of the manual allowed the various included entities to be challenged and tested and if proven valid to be revised in future editions. 43 The following table illustrates the main categories of the system: Table 2.3: The Diagnostic Classification of Sleep and Arousal Disorders A. Disorders of initiating and maintain sleep (DIMS) (Insomnias) B. Disorders of excessive somnolence (DOES) (Hypersomnias) C. Disorders of the sleep-wake cycle D. Dysfunctions associated with sleep, sleep stages or partial arousal (Parasomnias) The International Classification of Sleep Disorders (ICSD) (1990) The DCSAD was a useful tool and widely used but over the years a number of issues were highlighted, these being entries included twice, for example, sleep apnoea which was included in both DIMS and DOES and, as discussed earlier, this was due to the fact that the classification system was based upon symptoms rather than aetiology. Other sleep disorders were not classified accordingly and this only became apparent once the DCSAD had been integrated into the sleep medicine community and as mentioned previously a new edition would suffice if there were also new sleep disorders identified. Due to these issues with the DCSAD, The International classification of sleep disorders was produced in association with the American Academy of Sleep Medicine (AASM) with the European Sleep Research Society, the Japanese Society of Sleep Research and the Latin American Sleep Society in 1985 and was finally published in 1990; the classification was a revised edition form of the DCSAD. The ICSD (1990) was based on the formation of a questionnaire survey completed by sleep specialists. As a result of this survey it was stated that the ICSD would not be based on symptom but by the physiological manifestations of the presenting sleep disorder. Due to the advancements made in the last ten years or so since the first classification manual emerged, it was thought to be possible to be able to do this. Further evidence and research allowed parasomnias (discussed in section 2.1.4) to be given subcategories; further diagnostic information was needed through research on respiratory and neurological disorders. 44 The International Classification of Sleep Disorders-2 (2005) Introduction The American Academy of Sleep Medicine published the second edition of the International Classification of Sleep Disorders (ICSD-2) in 2005. The goals of the ICSD-2 were to scientifically and clinically describe all current sleep and arousal disorders and that the presentation of the disorders was scientifically valid and rational and lastly to ensure that the sleep and arousal disorders were compatible with the ICD-9 and the ICD-10. Originally it was thought that it would be possible for a common framework in which sleep disorders could be categorised, this notion had to be abandoned as it proved to be a impossible task. The ICSD-2 sorts the sleep disorders into eight categories which appear to be pragmatically and empirically valid (ICSD-2, 2005). In the ICD-2 some disorders are based on a common complaint (e.g., insomnia or Hypersomnia), other disorders are based on a basic aetiology, for example biological clock disturbances for circadian rhythm sleep disorders. Other disorders are based on depending which organ system the disorder arises from. The eight categories are: • Insomnia • Sleep related breathing disorders • Hypersomnias of central origin • Circadian rhythm sleep disorders • Parasomnias • Sleep related movement disorders • Isolated symptoms and normal variants • Other sleep disorders The members of the sleep committee who revised and updated the ICSD-2 understand that there are probably many cases of sleep pathologies that may not yet have been adequately documented in the sleep literature. To include a new disorder within the ICSD-2, it was necessary for the complaint to appear at two different sleep 45 centers, each of which had to have a minimum of two cases and published in specific reputable journals with a valid evaluation of the new disorder. With the ICSD-2 there may be a particular sleep disorder which may clearly belong to a particular sleep category but, for example, cannot be diagnosed as any specific disorder within that category because it does not satisfy the necessary diagnostic criteria. As well, if a particular sleep disorder cannot be classified due to the fact that there is not sufficient detail available to know whether or not all the diagnostic criteria have been met, then the clinician is required to select “unspecified” or “not otherwise specified” (NOS) as the appropriate diagnosis. The ICSD-2 can be used to classify sleep disorders in both adults and children. Differences between the ICSD-1 and ICSD-2 Although there were a large number of changes that concerned the individual’s sleep disorder, there were, however, also structural changes which occurred between the ICSD-1 and the ICSD-2. These are listed below: • There is no axial system for the ICSD-2, the ICSD-2 is only concerned with diagnosing sleep disorders as in axis A in ICSD-1. • The ICSD-2 does not contain a list of current procedures that the ICSD-1 did which were used to diagnose the sleep disorder. The committee felt that the procedures used in the study of sleep disorders across the world vary and differ. • In order to group the sleep disorders into eight categories it was agreed to eliminate the terms “intrinsic dyssomnias” and “extrinsic dyssomnias” • In the ICSD-2 the category ‘secondary sleep disorders’, for example those due to mental, neurologic and other medical disorders are not included. The rules of the ICD stresses that if the underlying mental, neurologic or other medical disorder is diagnosed then it no longer remains secondary, it becomes a primary disorder and therefore the category in which it falls under, for example mental, neurologic or medical are the symptoms. 46 • In the ICSD-2 there have been modifications made to the text outline used to describe the individual disorder. Impact on other classification systems Impact on ICD-9-CM Classification of sleep disorders within the current International Classification of Diseases (ICD-9-CM) was revised at the same time that ICSD-2 was published, in order to establish greater concordance between the systems. Many sleep disorders are now grouped into a single new series within the "Diseases of the Nervous System" section of ICD-9-CM, although some remain in other sections of ICD-9-CM (especially the "Mental Disorders" section). Limitations of the International Classification of Sleep Disorders-2 One of the key limitations of the ICSD overall is that as one revision is made, newer sleep disorders, sleep assessment tools and classification systems are being continually developed due to the advancement in knowledge and extensive research being conducted and contributing towards the ongoing development within the field of sleep medicine. Summary In summary it is important to see how rapidly the changes have occurred within the field of sleep medicine; this has been reflected in the way in which sleep disorders are classified. As advancements in research occur and our knowledge expands so will the current classification systems continue to develop. The specialists who have developed the latest edition of the ICSD-2 state that as the classification went to print there were already newer sleep disorders being discovered. The limitations of the ICSD-2 have also been discussed. 47 2.1.4 Sleep Disorders Section 2.2 described the classification systems of sleep disorders. This section will describe in detail the range of sleep disorders and sleep behaviours that have been identified using the ICSD-2 and information on the main features is provided. Section 2.1.5 will describe the range of methods of assessments that are available and Section 2.1.6 will introduce treatment strategies. Introduction Awareness of sleep disorders Sleep disorders are very common; they also have a very serious health, economic, social and occupational implication (Dement and Mitler, 1993). Professionally and educationally it has been shown that sleep medicine training is a neglected area both in medicine and psychology (Rosen, Rosekind, Rosevear, Cole and Dement, 1993; Wiggs and Stores, 1996). Despite sleepiness being a common symptom, those who suffer from sleep problems maybe reluctant to trouble their general practitioner (GP). Friends and family of the patient and sometimes the patient themselves are also known to trivialise their symptoms; for example, a person who snores heavily may have an underlying disorder such as obstructive sleep apnoea (OSA) so their symptoms will be shrugged off and the serious respiratory condition is left undetected (Shneerson, 2005). In the UK, sleep disorders remain amongst the most under-diagnosed and undertreated group of medical conditions (‘Dead Tired’ Report, 2006). In humans, sleep occupies approximately 8 hours of each 24-hour cycle but, according to recent research, much less attention has been paid to the medical problems associated with it than to those that occur during wakefulness (Shneerson, 2005). Justifications have been put forward to explain this. Patients are often reticent about events that occur during sleep (Shneerson, 2005). Patients usually regard this time as a personal and private time and are more reluctant to talk about problems occurring during sleep than about those occurring during wakefulness. Patients can also be unaware of any disorders surrounding their sleep at night and may only be 48 informed by a bed partner of disorders that involve irregular movements of limbs and perhaps obstructive sleep apnoeas. Usually sleep problems are attributed to problems that occur during the day or everyday life. This can be related to tiredness due to overwork or age but perhaps it may derive from a sleep disorder. Sleep disorders and sleep deprivation is on the increase in developed societies but the awareness of such disorders does not reflect the rate at which this increase is occurring (Groeger, Zijlstra and Dijk, 2000). Public education is required about the importance of sleep, its main components and good sleep hygiene. The effects of shift work and its consequences on sleep should also be made available (Terzano and Parrino, 2000). Awareness of these issues should be an important influence on those who have to make decisions regarding, for example, best practices at work, those who work in educational establishments and those who work in government establishments and have control over policies and regulations. These could help those who have to drive for long hours and such decisions can be made on motorways, on which there is greater risk related to sleepiness (‘Sleep SOS’, 2004). Medical staff and those who work as health care professionals are also generally less aware of sleep disorders, the assessment of sleep disorders, management of sleep disorders and the issues arising during the day with those who have sleep disorders (‘Sleep SOS’, 2004). Patients who go to see their physician usually do so during the day whilst they are awake and therefore no diagnosis can be made concerning their sleep issues. A survey concerning medical schools showed that sleep education was very minimal throughout undergraduate and postgraduate medical education (Stores and Crawford, 1998). Overseas, it is a similar story: an American survey of patients who attended a clinic to complain about their insomnia showed that on average only 2.5 questions were asked concerning the patients sleep complaint throughout the consultation. This is due to the fact that clinicians are not trained to deal with such complaints and are unaware of the possible causes and the effects of the symptoms upon the person (‘Sleep SOS’, 2004). This leads to a lack of any management plan to help the patient (Shneerson, 2005). 49 Costs of sleep disorders Through research it has been found that the costs of sleep disorders to society are potentially considerable (‘Sleep SOS’, 2004). Untreated obstructive sleep apnoeas have been associated with strokes or myocardial infarction, which may be avoided if the sleep disorder is recognised and dealt with early enough (Sert Kuniyoshi, 2008). Another factor is that of the reduction in the quality of life (Reimer and Flemons, 2003). Through extensive research into this area it has been found that excessive daytime sleepiness leads to irritability and difficulties in interpersonal relationships. This not only impairs social activity but also can reduce and will reduce productivity at work. Studies involving patients diagnosed with OSA before and after continuous positive airway pressure treatment have been shown to have a reduced quality of life before treatment; after treatment QoL improves (McArdle, Kingshott, Engleman, Mackay and Douglas, 2001). Patients diagnosed with narcolepsy have been shown to have the same life quality decrease prior to being prescribed modafinil (a drug that ensures wakefulness) and after treatment show a significant increase. Lastly, excessive daytime sleepiness impairs work productivity and can lead to accidents that may have considerable financial consequences, due to those who have to take time off work. Daytime sleepiness and insomnia appears to be on the increase (Shneerson, 2005). These costs can be avoided with better awareness of sleep disorders and the treatment and advice made available to patients (‘Sleep SOS’, 2004) The cost of providing facilities whereby such diagnosis and prognosis can be made should be offset against potential savings (‘Sleep SOS’). Indeed sleep laboratories, polysomnography and training staff is expensive but surely the cost to society when lacking in these facilities is more costly. Costs of treatment can be reduced if the simplest and effective methods are used first rather than the more complex and timeconsuming ones, such as polysomnography. Most drugs that are available to treat sleep disorders are available at a reduced cost, such as benzodiazepines, hypnotics and antidepressants. Treatments such as CPAP and light therapy are more expensive. The intervention of the medical team together with supervision of the patient has to be balanced against the benefit they provide. 50 The ICSD-2 It is important to note that the sleep disorders and behaviours mentioned in this section are not mutually exclusive. One particular sleep disorder may occur at the same time as another and one may even have an impact on another. It is also important to clearly define at this stage certain terms that are associated with sleep, these being ‘behaviour’, ‘problem’ and ‘disorder’. So, a behaviour associated with sleep may or may not be a problem, for example night waking is physiologically normal; it only becomes a problem if the individual or perhaps the individual’s bed partner is troubled by it (the bed partner may continue to remain awake during the night because of their partner’s snoring). Laymen tend to equate sleep problems with sleep behaviour but disorders are when there is something physiologically abnormal about the individuals sleep. In these terms, the behaviour and the problem associated with sleep may not be a disorder. In this thesis, ‘sleep disorder’ implies a behaviour that is a problem, regardless of whether or not it is dependant on abnormal physiology. Sleep behaviours such as teeth grinding, sleep taking and hypnogogic jerks are not necessarily a problem. Insomnia The ICSD-2 defines insomnia as a “repeated difficulty with sleep initiation, duration, consolidation, or quality that occurs despite adequate time and opportunity for sleep and results in some form of daytime impairment” (ICSD-2, 2005). Adjustment Insomnia (Acute Insomnia) With adjustment insomnia the essential feature is the presence of insomnia in association with an identifiable stressor. The sleep disturbance is of short duration from a few days to a few weeks. The sleep disturbance will resolve once the main stressor has been dealt with or if the individual is able to cope with the stressor. Psychophysiological Insomnia With psychophysiological insomnia the essential feature is heightened arousal and learned sleep-preventing associations that result in a complaint of insomnia and the associated decreased functioning during wakefulness. 51 Idiopathic Insomnia With idiopathic insomnia the essential feature it is usually a life-long inability whereby the patient is unable to obtain adequate sleep and this may perhaps be due to an abnormal neurologic control of the sleep-wake system; this being a neurochemical imbalance of either the arousal system or the many sleep-inducing and sleepmaintaining systems. Insomnia due to Mental Disorder In insomnia due to mental disorder the essential feature is the occurrence of insomnia that is caused by an underlying mental disorder. The insomnia usually begins at the onset of the mental disorder and will usually mirror the disease as it changes. Inadequate Sleep Hygiene One of the essential features of inadequate sleep hygiene is that the insomnia is associated with daily living activities that are inconsistent with the maintenance of good quality sleep and full daytime alertness. The specific behaviours that are a common element of this disorder can be classified into two general categories, behaviours that produce increased arousal and behaviours that are inconsistent with the principles of sleep organisation. Insomnia due to Medical Condition One of the essential features associated with this condition is that it is caused by a coexisting medical or physiological condition. Usually this particular sleep disorder is associated with sleep initiation or maintenance and non-restorative and poorquality sleep. Sleep related Breathing Disorders The disorders in this sub-group share one common feature: disordered respiration during sleep. 52 Primary Central Sleep Apnoea One of the essential features of primary central sleep apnoea (PCSA) is of unknown aetiology (idiopathic) and is usually characterised in the polysomnogram by recurrent cessation of respiration during sleep with the apnoea having no associated ventilatory effort. Usually in patients with CSA ventilation and ventilatory effort repetitively ceases over the course of the night. This pattern leads to sleep fragmentation and tends to produce excessive daytime sleepiness and or frequent nocturnal awakenings. Cheyne Stokes Breathing Pattern One of the descriptions of Cheyne Stokes breathing is that it produces recurrent apnoeas, hypopnoea or both apnoeas and hypopnoeas which can alternate with prolonged hyperpnoea which leads to the tidal volume to gradually increase and then decrease, this prolonged increasing and decreasing pattern of hyperpnoea is the hallmark of Cheyne-Stokes breathing pattern and it also distinguishes it from other forms of CSA. Central Sleep Apnoea due to Drug or Substance Users of long-acting opioids may have central apnoea during sleep. The most common drug to cause this sleep disorder is methadone, but, time-release morphine and hydrocodone can also be responsible. Obstructive Sleep Apnoea Syndromes Also known as sleep apnoea, sleep apnoea syndrome, obstructive apnoea, mixed sleep apnoea, sleep-disordered breathing, sleep hypopnoea syndrome and lastly upper airway obstruction. Obstructive sleep apnoea (OSA) is characterised by repeated episodes of complete apnoea or partial hypopnoea in which the upper airway is obstructed during sleep. OSA often results in reductions in blood oxygen saturation; these events are usually terminated by brief arousals from sleep. Apnoeic and hypopneic events last by definition, a minimum of ten seconds; most events last from ten to thirty seconds in 53 duration but can persist for one minute or longer. Apnoeic and hypopneic events can usually occur in any stage of sleep but are most frequent in stage 1 and 2 NREM and REM sleep rather than in stage 3 or 4NREM sleep. Events that occur in REM sleep take longer and associated with more severe decreases in oxygen saturation; this usually returns to baseline values once normal breathing has resumed. Snoring usually occurs between apnoeas as reported by bed partners as do episodes of choking and gasping with frequent movements that disrupt sleep. Symptoms are exacerbated following the ingestion of alcohol prior to sleep or an increase in body weight. Patients report feeling unrefreshed from their sleep upon awakening, symptoms such as disorientation, unsteadiness, mental dullness, in-coordination, severe dryness of the mouth and morning headaches. Sleep-related Hypoventilation/Hypoxemic Syndromes Sleep-related Non-obstructive Alveolar Hypoventilation, Idiopathic This sleep disorder is characterised by a decrease in alveolar ventilation; this results in sleep-related arterial oxygen desaturation in patients with normal mechanical properties of the lung. When patients present with diurnal as well as nocturnal hypoventilation without a readily identifiable pulmonary, endocrine, neurological, ventilatory, muscle or cardiac cause, the condition will be referred to as idiopathic alveolar hypoventilation. Typically, the sleep-related hypoventilation develops in the early stages of the condition that is a result of removal of the wakefulness stimulus to breathe. Sleep- related Hypoventilation/Hypoxemia due to Lower Airways Obstruction These disorders are characterised by obstruction or an increase airflow resistance in the airway below the laryngeal apparatus. Sections 2.9 and 2.10 discuss the nature of chronic obstructive pulmonary diseases and bronchiectasis, which are both lower airways diseases respectively. Hypoxemia is a medical term used to describe insufficient oxygenation of arterial blood. Patients who are diagnosed with chronic obstructive pulmonary disease and 54 bronchiectasis or other lower airway obstructions are increasingly predisposed to developing hypoventilation/hypoxaemia as the severity of the underlying lower airways obstruction increases. Other Sleep Related Breathing Disorders Sleep Apnoea/Sleep related breathing disorder, unspecified. These terms are used for sleep related breathing disorders (SRBD) which cannot be classified elsewhere or may not neatly fit into one category but are due to respiratory disturbance in sleep. Hypersomnias of Central Origin not due to a Circadian Rhythm Sleep Disorder, Sleep Related Breathing Disorder or other cause of disturbed Nocturnal Sleep. Alertness is necessary for well-being and performance in modern society (ICSD-2, 2005). Individuals who experience sleepiness are predisposed to developing serious performance impairment in a number of areas of function as well as their own personal and social areas. This section includes a group of disorders in which the primary complaint is daytime sleepiness but the cause of the primary symptom is not disturbed nocturnal or misaligned circadian rhythms. Other sleep disorders may be present and they must be first treated prior to establishing diagnoses within this category. Narcolepsy with Cataplexy This sleep disorder is primarily characterised by excessive daytime sleepiness and cataplexy. The symptoms associated due to narcolepsy with cataplexy are present due to an unusual inclination to transition rapidly from wakefulness into REM sleep and to experience dissociated REM sleep events. One of the most disabling symptoms of this sleep disorder is excessive daytime sleepiness. Patients with narcolepsy with cataplexy usually have repeated episodes of lapses into sleep across the daytime. Patients will usually sleep for a short duration and awaken refreshed but within two of three hours will begin to feel sleepy again. This pattern is repeated throughout the day. Sleepiness usually occurs in monotonous situations (a lack of 55 cortical stimulation). Sleep attacks can also occur in unusual situations such as eating, walking and sleeping. Sleepiness will usually vary in severity and cannot be easily distinguished whether it is due to insufficient sleep or other sleep disorders. Cataplexy is usually characterised by a sudden loss of bilateral muscle tone and is provoked by strong emotions that are usually positive such as laughter, pride, elation or surprise. Negative emotions such as anger can also be a trigger. Cataplexy can be localised or can include all skeletal muscle groups. Lower and upper limbs, including the neck, mouth or eyelids can be affected; those areas that are affected are the knees, face and neck. Vision can be blurred, respiratory muscles are never affected but patients may experience a choking sensation if the cataplexy occurs in an awkward position. The duration of the attack of cataplexy is usually short and can range from a few seconds to several minutes and recovery is immediate. Narcolepsy without Cataplexy One of the key features of narcolepsy without cataplexy is excessive daytime sleepiness and is associated with naps that are refreshing in nature while nocturnal sleep is normal or moderately disturbed without prolonged periods of sleep. Other characteristics that may be present are sleep paralysis, hypnagogic hallucinations or automatic behaviour. The attacks can last for 3 minutes or so. One of the features necessary for diagnosis for this sleep disorder is that sleep latency must be less or equal to eight minutes and two or more sleep onset rapid eye movement periods (SOREMPs) on a multiple sleep latency test (MSLT) must be present. Narcolepsy due to Medical Condition One of the causes for narcolepsy due to a medical condition is a coexisting medical or neurological disorder. In patients presenting with this condition, the narcolepsy must be clinically or polysomnographically documented. The severity of daytime sleepiness is usually varied. Other characteristics such as sleep paralysis, hypnagogic hallucinations, insomnia or automatic behaviour may or may not be present. 56 Medical conditions, such as tumours or sarcoidosis of the hypothalamus, multiple sclerosis plaques that impair the hypothalamus, have been shown to produce genuine characteristics of secondary narcolepsy with cataplexy. Recurrent Hypersomnia (including Kleine-Levin syndrome and MenstruationRelated Hypersomnia A key feature of this sleep disorder is recurrent episodes of hypersomnia, typically occurring weeks or months apart. Episodes of hypersomnia usually last from a few days to several weeks and can appear once to ten times a year. Episodes are often preceded by prodromes such as fatigue or headaches that can last for a few hours (ICSD-2, 2005). Idiopathic Hypersomnia with Long Sleep Time A characteristic feature of this disorder is characterised by severe excessive sleepiness but with unrefreshing naps of up to three or four hours and a prolonged major sleep episode and a greater difficulty in waking up either in the morning or at the end of a nap. Idiopathic Hypersomnia without Long Sleep Time The diagnostic feature of this sleep disorder is that patients complain about constant and severe excessive daytime sleepiness. Such excessive daytime sleepiness usually results in unintended naps which are generally of an unrefreshing nature. Behaviourally Induced Insufficient Sleep Syndrome This sleep disorder often occurs when patients persistently fail to obtain the amount of sleep usually required to maintain normal levels of alertness and wakefulness. Patients diagnosed with this sleep disorder often have unintentional chronic sleep deprivation and upon examining patients this reveals unimpaired or above-average ability to initiate and maintain sleep. 57 Hypersomnias not due to Substance or known Physiological Condition (Nonorganic Hypersomnia) A characteristic feature of this disorder is excessive nocturnal sleep, daytime sleepiness; excessive napping is usually reported. Patients will report their sleep to be of poor quality and unrefreshing. Patients tend to focus on their hypersomnia and after episodes of interviews and psychometric testing psychiatric symptoms become apparent. Circadian Rhythm Sleep Disorders Sleep disorders that fall into this subgroup arise when the physical environment is altered relative to internal circadian timing or the circadian rhythm timing system that is altered relative to the external environment. Circadian Rhythm Sleep Disorder, Delayed Sleep Phase Type, (Delayed Sleep-Phase disorder) This disorder is marked by the following factors: 1. Sleep-onset and wake times are later than desired. 2. Actual sleep-onset times at nearly the same daily clock hour. 3. There is little or no reported difficulty in maintaining sleep once sleep has begun. 4. Extreme difficulty in waking up at the desired time in the morning. 5. An inability to advance the sleep phase to earlier hours by ensuring sleep and wake times. There is usually no psychopathology present. 58 Circadian Rhythm Sleep Disorder, Advanced Sleep Phase Type, (Advanced SleepPhase disorder) The advanced sleep-phase disorder is marked by a patient’s chronic inability to delay the onset of evening sleep, the patient may also sleep later into the morning to enforce conventional social sleep and wake times. Circadian Rhythm Sleep Disorder, Irregular-Sleep Wake Type, (Irregular SleepWake Rhythm) Patients with Irregular Sleep-Wake Rhythm may have a total of 24-hour sleep time averagely, but the single sleep period is by no means of normal length; there is, too, unpredictability in the patient being asleep at any particular time of the day. Circadian Rhythm Sleep Disorder, Shift-Work Type, (Shift Work Disorder) This disorder arises from irregularly scheduled hours of work during the habitual hours of sleep; this can be shift work-rotating or permanent shifts, roster work, or irregular work hours. The patient will report an inability to maintain a normal sleep duration when the major sleep episode has begun in the morning after a night shift. There is usually a reduction in sleep length, by one to four hours, which affects REM and stage 2 sleep (Folkard and Barton, 1993). Parasomnias This particular group of sleep disorders are classed as parasomnias and are usually undesirable physical events or experiences that occur during entry into sleep, within sleep or during arousals from sleep. These particular events usually manifest through the central nervous system (CNS) activation transmitted into skeletal muscle and automatic nervous system channels. Parasomnias involve abnormal sleep related movements, behaviours, emotions, perceptions, dreaming and automatic nervous system (ANS) functioning. 59 Disorders of Arousal (from Non-Rapid Eye Movement Sleep) Confusional Arousals Patients diagnosed with confusional arousals usually have such symptoms due to mental confusion or confusional behaviour during or following arousals from sleep, these arise from slow-wave sleep in the first part of the night, and also when patients attempt to awaken from their sleep in the morning. Sleepwalking also known as Somnambulism Sleepwalking consists of a series of complex behaviours that originate during slow wave sleep and result in waking during sleep. Patients can either just sit up in bed or sleepwalk or display frantic attempts to escape. It is usually difficult to wake the patient and when aroused they are mentally confused. Sleep talking is also present during sleepwalking. Sleep Terrors also known as Night terrors Sleep terrors arise from arousals from slow-wave sleep that can be accompanied by a cry or a piercing scream and ANS and behavioural manifestations of intense fear. The person usually sits up in bed and is unresponsive to external stimuli and if the patient is awakened during the episode they will be confused and disorientated. Parasomnias usually associated with Rapid Eye Movement Sleep Rapid Eye Movement Sleep Behaviour Disorder (Including Parasomnia Overlap Disorder and Status Dissociatus) REM sleep behaviour disorder (RBD) is characterised by abnormal behaviours that emerge during REM sleep which can cause injury or sleep disruption. This is associated with electromyographic (EMG) abnormalities during REM sleep. The electromyogram will demonstrate an excess of muscle tone or phasic EMG twitch activity during REM sleep. Nightmare Disorder This sleep disorder is often characterised by recurrent nightmares that are disturbing mental experiences, tending to occur during REM sleep and often resulting in 60 awakening. For patients with this sleep disorder the actual nightmare episode will appear to be very real and will become increasingly disturbing as the nightmare unfolds. Anxiety, fear, or terror will usually accompany the episode; however, emotions such as anger, rage, embarrassment, disgust and other negative feelings are associated with nightmares. Other Parasomnias Sleep Related Dissociative Disorders These sleep disorders emerge throughout the sleep period during well-established EEG wakefulness. This can occur at either the transition from wakefulness to sleep or within several minutes after an awakening from stages 1 or 2 NREM sleep or from REM sleep. The three categories to date that have been associated with nocturnal dissociative disorders are dissociative personality disorder (formerly known as multiple personality disorder), dissociative fugue, and dissociative disorder that has not been specified. Sleep Related Eating Disorder Sleep related eating disorder (SRED) consists of recurrent episodes of involuntary eating and drinking during arousals from sleep with problematic consequences. They can occur during partial arousals with partial recall from the patient. Patients usually cannot be brought to full consciousness during an episode. Sleep Related Movement Disorders Sleep related movement disorders are conditions that are primarily characterised by relatively simple and usually stereotyped movements that disturb sleep or other sleep related monophasic movement disorders, such as sleep related leg cramps. Restless Legs Syndrome Restless legs syndrome (RLS) is a sensorimotor disorder that is characterised by a complaint of a strong, nearly irresistible, urge to move the legs. The urge to move the legs is often but not always accompanied by an uncomfortable sensation felt deep inside the legs or a feeling which is simply difficult or impossible to describe. The sensations can be painful too. The urge to move usually occurs or is made worse by 61 resting (lying and sitting) and walking or moving the legs often relieves the sensations. The sensations are worse in the evening and during the night. Sleep related Leg Cramps These are usually painful sensations that are caused by sudden and intense involuntary contractions of muscles or muscle groups. The cramps occur in the calf or small muscles of the foot and occur during the sleep period and they may arise from either wakefulness or sleep. The cramps can be sudden or in some cases be preceded by a less painful warning sensation. The contractions can last for a few seconds or up to several minutes and then diminish spontaneously. Cramps can be relieved by intense stretching of the affected limb or by massaging the site. Sleep Related Bruxism This is an oral activity characterised by grinding or clenching the teeth during sleep that is often associated with sleep arousals. During sleep jaw contraction usually occurs, this contraction can take on two forms, the first being sustained jaw clenching which are also known as tonic contractions or a series of repetitive (phasic) muscle contractions termed rhythmic masticatory muscle activity (RMMA). When the contractions occur during sleep they are very strong and they tend to produce tooth-grinding sounds and this often referred to as sleep related bruxism. This often leads to abnormal wear of the teeth and also causes tooth pain, jaw muscle pain and or temporal headaches. Sleep is often disrupted during severe episodes of sleep related bruxism. The disorder is usually brought to the attention of dental or medical professionals because of the tooth damage which the grinding causes, and the unpleasant sounds made by the patient with can be disturbing to any bed partner. Isolated Symptoms and Normal Variants These are disorders which lie at the borderline between normal and abnormal sleep or that exist on the continuum of normal to abnormal events in sleep (ICSD-2, 2005). 62 Long Sleeper A long sleeper is a patient who consistently sleeps longer than is considered normal for his/her age group. Sleep architecture is present and normal. Again there are no complaints about quality of sleep, daytime sleepiness, or impaired daytime functioning. Sleep that is more than ten hours per 24 hours is considered unusually long in young adults. Sleeping less than this amount leads to daytime symptoms of excessive sleepiness in this group. Short Sleeper A short sleeper is a patient who has a shorter sleep episode than is considered normal with no complaints about the quality of sleep or reduced daytime wakefulness and functioning. Sleep episodes of less than five hours per 24-hour period is usually considered short before the age of 60 years. Snoring Snoring is a respiratory sound that is generated in the upper airway during sleep that typically occurs during inspiration but can also occur in expiration. The snoring that occurs within this subgroup occurs without episodes of apnoea and or hypoventilation. The intensity of the snoring can vary and will often disturb a bed partner. This particular type of snoring does not cause daytime sleepiness or insomnia. Sleep Talking This condition consists of utterances of speech/sounds during a sleep episode without any detailed awareness of the event. Bedpartners and household members may find that emotional stress is not an underlying cause; however, the episodes may be frequent; nightly longer speeches occur which can be hostile and aggressive. It can be spontaneous. Sleep Starts (Hypnagogic Jerks) These are sudden, brief, simultaneous contractions of the body or one or more body segments occurring at sleep onset. Sleep starts consist of a single contraction that 63 often affects the body asymmetrically. The jerks can often be spontaneous or brought on by stimuli. Patients often report a feeling of falling, a sensory flash or a visual hypnagogic dream or hallucination, and the jerks often occur in a succession. Other Sleep Disorders These are sleep disorders that cannot be classified elsewhere in the ICSD-2 and are listed within this sub-group usually the final diagnosis will have a physiological or medical related diagnosis Other Physiological (Organic) Sleep Disorder This category can also act as a final diagnosis for those disorders that cannot be diagnosed are also classified here. Sleep disorders not classifiable elsewhere throughout the ICSD-2 but with a medical, a substance, or a psychiatric aetiology are classified here. Other Sleep Disorder not due to Substance Abuse or known Physiological Condition These disorders usually have a underlying psychiatric or behavioural factor. Environmental Sleep Disorder This is a sleep disorder usually caused by sleep disturbances due to a disturbing environmental factor which causes a complaint of insomnia or daytime fatigue and somnolence. Summary Not every sleep disorder has been discussed in this chapter. The list, while exhaustive with regard to current knowledge, must be acknowledged to be perpetually incomplete as there are newer sleep disorders being continuously discovered. The succeeding editions of the ICSD have been designed to accommodate these changes as they arrive. Some of the similarities between disorders, self evident throughout this chapter, derive from underlying behavioural, physiological and psychiatric factors that are usually present throughout all known sleep disorders. 64 2.1.5 Assessment of Sleep Disorders To understand what can go wrong during sleep and to assess these problems, it is important to be able to understand normal sleep. When initially investigating disordered sleep it is important to obtain a detailed historical account during an interview with the patient and often with other members of the family. This detailed account should be supplemented by a physical examination where appropriate (Shneerson, 2005). Although there are a range of techniques available to assess disordered sleep, any such examination should only be conducted with clear aims (Shneerson, 2005). This section assesses the use of the sleep history and examination and the methods used to assess sleep and its disorders. History taking For clinical reasons it is often more difficult to take a patient’s history of a sleep disorder than it is to enquire about their complaint that occurs during wakefulness. Obviously, this is because the patient usually has little or no awareness of the problem and it is often important to obtain the bed partner’s (if any) views of the events that occur during the sleep episode and during wakefulness (Shneerson, 2005).The aim of this procedure is to be able to establish whether or not there is a sleep disorder and to assess the relative contribution of psychological, medical and social factors to the complaint (Shneerson, 2005). The symptoms and the sequence of the appearance of the complaints should also be recorded, together with when the complaint started and how it has progressed (Shneerson, 2005). As part of the investigation process, detailed sleep questionnaires, such as the Pittsburgh Sleep Quality Index (PSQI) have been developed to cover important questions that need to be asked during the interview phase. Questionnaires such as the PSQI supplement a conventional history and can also act as a substitute if the history is unavailable. Usually a detailed history is preferable and usually the first step of the diagnostic process is to assess the patient’s complaint or the reason for seeking attention. It is important to establish whether the presenting problem is primarily insomnia, excessive daytime sleepiness or abnormal experiences or movements during sleep. Once this has been established it is important to establish when the sleep problem began and whether there was any relationship to an external 65 factor, which may be physical, such as a head injury, or one more subtle and psychological in nature. Factors to consider during history taking It is often useful to consider the details of events during sleep and wakefulness as a twenty-four-hour-cycle. Within this twenty-four-hour-cycle the events that should be examined are as follows: The sleep-wake patterns of the patient; this includes what time the patient goes to bed, what time the patient goes to sleep, what time the patient wakes up in the morning and what time they get out of bed and any events which may occur during the night. Events on awakening; does the patient feel refreshed? Are there any symptoms such as frontal headaches, sometimes an indicator of carbon dioxide retention, caused by hypoventilation during sleep? Is the patient alert? It is also important to note daytime activities; for example are naps being taken during the day and if this is the case, how long are the naps lasting for and how often are they being taken? Important factors to note within this particular observation are any sensory symptoms that the patient displays, especially delirium tremens. These may be indicative of an underlying cause. Are there any memory or concentration problems? And are there any symptoms related to motor problems? Excessive daytime sleepiness; firstly, it is important to distinguish between true hypersomnia and hypersomnolence, the former being based on sleep patterns which are abnormal in the sense that the subject will sleep for a long period during a twenty-four-hour-cycle and the latter being the sensation of sleepiness. It is also important to distinguish between these two symptoms; they should be distinguished from mental fatigue with poor concentration or motivation, physical weariness or fatigue that may have an organic cause or may be related to insomnia, and the feeling of subalertness. The duration, frequency and timing of naps should also be considered and whether or not these episodes are refreshing. 66 Clinicians can usually gauge the severity of daytime sleepiness by its frequency and the type of situation in which the subject falls asleep. If it is mild, it only occurs infrequently during periods when sleep would be most expected, for example between 2 PM and 4 PM or during late evening or during monotonous events. Cyclical sleepiness may be due to intermittent sleep deprivation. In this case, patients find themselves sleeping little during the week and tend to catch up on their sleep debt over the weekend. This then leads to a cycle of sleepiness and recovery. Longer cycles that occur are usually indicative of other disorders. Other factors which should also be included in the history taking are factors such as: pre sleep activities and symptom, other related problems (muscle aches, headaches), social history, general health, medical history, family history, drug history and a short physical examination which can be a good indicator for specific disorders. Factors to consider when examining the patient physically are attitudes of the patient and any bed partner to the presenting sleep complaint are important. Clinicians may also want to note the weight and neck circumference and examine the nose and the pharynx that may suggest obstructive sleep apnoeas. Checking the teeth is also important, as ground-down teeth are a presenting feature of bruxism. The clinician will usually perform a detailed examination of the patient presenting with the complaint to rule out any other underlying disorders. Objective methods Polysomnography Polysomnography, also known as a sleep study, is a multi-parametric test (Carskadon and Rechtschaffen, 2005). It is used in the study of sleep and as a diagnostic tool in sleep medicine. The sleep study is a broad recording of the biophysiological changes that occur in a subject’s sleep. The test is usually performed at night, although some sleep laboratories do accommodate shift workers or those with circadian rhythm sleep disorders. The polysomnogram monitors body functions including brain (electroencephalogram (EEG), eye movements (Electro-oculogram-EOG) and muscle activity or skeletal muscle activation (Electromyogram) and heart rhythm (Electrocardiogram) during the patients sleep. Other factors such as respiration 67 together with pulse oximetry are also investigated and will be discussed in a later section. Polysomnography can be used to diagnose many sleep disorders and eliminate those that are not present. Disorders such as narcolepsy, restless legs syndrome, REM behaviour disorder, parasomnias and sleep apnoea can be diagnosed with a polysomnogram. The polysomnography test is being replaced by actigraphy. Actigraphy This is usually a non-invasive method of monitoring human rest/activity cycles. The patient, to measure gross motor activity, wears a small actigraph unit, also known as an actimetry sensor. The part of the body whose motor activity is often under test are wrist movements. Sleep actigraphs are generally watch-shaped and worn on the wrist of the non-dominant arm. Actigraphs are useful in determining sleep patterns and circadian rhythms; they can be worn for weeks at a time. These tests are useful for measuring and assessing daytime sleepiness in situations where a laboratory or a sleep latency test (discussed later in a different section) is not appropriate. The actigraphs can be used to clinically evaluate insomnia, circadian rhythm sleep disorders and excessive sleepiness and restless leg syndrome. The actigraph can also be used to assess the effectiveness of pharmacologic, behavioural, phototherapeutic and chronotherapeutic treatments for such disorders. Actigraphy has not been traditionally used in routine diagnosis of sleep disorders but is increasingly being used in sleep clinics to replace full polysomnography. The technique is more extensively used in academic research and is being increasingly employed in new drug clinical trials where sleep quality is seen as a good indicator of quality of life (American Academy of Sleep Medicine, 2002). Actigraph units tend to vary widely in size and features and can be expanded to include additional measurements. There are a number of limiting factors, however, such as fastest sample rate, the amount of memory available, battery usage, the weight of the unit and water resistance qualities so that the actigraph can be worn in the shower. The actigraph does have some advantages such as watch functionality, for example making the device more attractive to the user. User input, most 68 actigraphs now include a button so the user can indicate a specific event that occurs, subjective input, to allow surveys at specific times and sensors which monitor temperature, ambient light, sound levels, parkinsonian tremor, skin resistance and a full EEG data stream can be included. Video and audio recording Video recordings are usually often used together with various other methods of sleep assessments, providing additional information. Video recordings can reveal particular parasomnias. Infrared cameras and those sensitive to low light levels reduce the level of interference with the individual’s sleep. Video and audio recordings have been used in conjunction with other measures when investigating sleep related breathing disorders (Stradling, Thomas, Warley, Williams and Freeland, 1990; Ali, Pitson and Stradling, 1993). Vos and Stradling (1991) have developed a system to automatically process video and audio recordings or movements as a measure of sleep disturbance and degree of snoring as a measure of disordered breathing. Subjective Methods The above mentioned assessments of sleep and its disorders are very specialised methods; in some cases such methods may not be available or required. The following section describes subjective methods of assessments and discusses their usefulness in research and clinical settings. Questionnaires Questionnaires can be a useful method for assessing sleep. Questionnaires can be designed to assess both children and adults. Questionnaires can be used to obtain information about a wide range of sleep disorders and behaviours plus their severity. Questionnaires can be used to assess excessive sleepiness, quality of sleep, sleep disordered breathing. In this section questionnaires used to assess the quality of sleep will be discussed. Questionnaires that measure excessive sleepiness and sleep disordered breathing will be discussed in a different section. “Sleep quality is an important clinical construct” (quoted from Buysse, Reynolds, Monk, Berman and Kupfer, 1988). Patients will often complain about their sleep and 69 epidemiological studies have shown that fifteen to 35% of the adult population commonly complain about their quality of sleep. Difficulty in falling asleep and difficulty maintaining sleep are frequent complaints (Karacan, Thornby, Anch, Holzler, Warheit, Schivab and Williams, 1976; Karacan, Thornby and Williams, 1983; Lugresi, Cirignotta, Zucconi, Mandini, Lenzi and Coccagna, 1983; Welstein, Dement, Redington and Guilleminault, 1983 and Mellinger, Balter and Uhlenhuth, 1985). Research has found that sleep quality that is poor can be an important marker for many sleep and medical disorders (Kripke, Simons, Garfinkiel and Hammond, 1979). Complaints about the quality of patients’ sleep are particularly important in psychiatry (Buysse et al, 1988). Some of the underlying factors, which contribute to general complaints about the quality of sleep, are anxiety and stress (Karacan et al, 1983). Although it is often difficult to define and objectively measure sleep quality (Buysse et al, 1988), objectively, sleep quality includes quantitative measures such as duration of sleep, sleep latency, the number of arousals throughout the night, as well as those aspects of sleep quality which can be subjectively collected, these being depth of sleep and restfulness of sleep (Buysse et al, 1998). Usually research which wishes to focus on a person’s sleep quality will often be affected by the type of study being conducted and the tools used to measure the variable. Usually large population surveys tend to focus on a few general questions about the individuals quality of sleep (Bixler, Kale, Soldatos, Kales and Karacan, 1979; Karacan et al, 1983). Diaries Sleep diaries or sleep logs are usually kept by the individual when requested to do so by medical or academic staff. The sleep diary is a record of the individuals sleeping and waking times with related information; the diary is usually kept over several weeks. The diary is self-reported or can be used by the caregiver on the patient’s behalf. The sleep diary is a tool used by clinicians (Perlis, Jungquist, Smith and Posner, 2005). It is often a useful tool used to diagnose circadian rhythm disorders and in monitoring whether or not the treatment used for the disorder is useful. Sleep diaries can often be used together with actigraphy. It is also useful for the patient in order to 70 understand what is affecting their sleep. This alone can often help individuals understand and self-diagnose. Sleep assessment for sleep-related breathing disorders Objective methods It is often important to accurately obtain a careful history to assess disorders of the upper airways. The issues, however, that should be considered when there is sleep disturbance, too, are as follows: What kind of noise is the patient making? This should include factors such as duration, severity and the type of noise that is being produced and if this noise is becoming louder and more frequent. What is the respiratory pattern like when the noise is being generated? Is the bed partner aware of how the breathing starts and stops, and is there any noise associated with this sound? The patient may however occasionally awaken during the night for no apparent reason; this could be due to the noise or due to the sensation of choking. Are there any associated symptoms, for example physical restlessness during the patients sleep? Does the patient experience excessive daytime sleepiness? Is there any cause for any upper airway obstruction? Has the patient gained weight or has their collar size increased? Does the patient have any nasal obstructions? Do they smoke, drink alcohol, take medication; is there anything wrong with their sleep hygiene? Is there any aspect of their medical history that the clinician should be aware of, especially concerning the patients face or nose? The above questions will usually be asked together with a physical examination; the clinician will pay particular attention to any weight gain and observe if there is obesity and if the patient presents with any upper airway abnormalities and abnormalities of the neck. The patient will usually be observed during a sleep study; if there is any obstruction during sleep then the patient will usually have either noisy 71 breathing or intermittent silences during the apnoeas followed by a snort or similar noise at their termination. If the apnoea is present, this will also be further supported by the observation of the chest movement which will be paradoxical. Once these preliminary tests have been performed, initial assessments will also include a thyroid function test; tests for arterial blood gases, ECG and an echocardiogram. A chest x-ray and respiratory function tests are only carried out if there is a respiratory disorder already present. Respiratory movements are also measured using inductance, impedance or magnetometry methods or by using mercury strain gauges. If there are any upper airway obstructions or airway abnormalities then there may be paradoxical chest movement. Respiratory effort can be estimated by measuring oesophageal pressure, which will reflect the intrapleural pressure. The technique is invasive in that it requires swallowing a balloon or catheter into the oesophagus. Pulse Oximetry Pulse oximetry has become the standard approach for recording blood oxygen desaturation during overnight sleep studies. Pulse oximeters measure arterial oxygen saturation; this is measured by using a spectrophotoelectrical technique through a two-wavelength light transmitter and a receiver placed on either side of a pulsating arterial vascular bed. Sites that are used are the digits, ear and nasal sites. Usually any changes detected by the receiver depend upon the change in arterial pulse. The wavelengths are transmitted through the arterial vascular bed and arterial oxygen saturation of the arterial haemoglobin. The device is very sensitive and will not interfere with arterial oxygen saturation measurements. It is important to correctly align the light transmitter and receiver. If the sensor is applied to a digit then the digit must be immobilised, this is so that the device can detect a pulsatile flow. 72 Assessment of daytime sleepiness This section describes the techniques used for evaluating self-reported sleepiness. The Multiple Sleep Latency Test (MSLT), pupillography and ECG approaches are discussed, along with the Maintenance of Wakefulness Test and vigilance testing are described. The limitations and advantages of using self-reported sleepiness tests are also discussed. Introduction Excessive sleepiness is a serious condition, which does not just affect the patient but also his or her colleagues, friends, and family; it can be life-threatening (Mitler, Carskadon and Hirshkowitz, 2005). Clinically it is very important to assess daytime sleepiness (Mitler, Carskadon and Hirshkowitz, 2005). The right tools are required, however, to assess the condition. There are specific issues relating to measurement, in particular the tools used to measure daytime sleepiness. The first issue concerns difference between withinsubject comparisons and between-subject comparisons. The second issue concerns self-report, factors concerning whether the patient is under or over exaggerating can be a cause for concern (Mitler, Carskadon and Hirshkowitz, 2005). The third issue concerns clinical testing of sleepiness that usually involves daytime testing. A traditional and a more conceptualised method for assessing daytime sleepiness was based on three factors: physiologic sleepiness, manifest sleepiness and introspective sleepiness (Carskadon and Dement, 1982). This model provides an organisational method of understanding and measuring sleepiness. Physiological sleepiness is described as the underlying biological drive to sleep, this being the speed at which the individual falls asleep. Manifest sleepiness originates from three perspectives, these being behavioural signs of sleepiness, the individual’s inability to remain awake and the decline in the performance of psychomotor or cognitive tasks. Thirdly, introspective sleepiness deals with an individual’s self-assessment of an internal state. 73 Physiological measures of sleepiness The MSLT is a series of opportunities for the patient to nap (approximately four to six) that is presented at two-hour intervals and these begin at approximately two hours after initial morning awakening. Those who undergo the MSLT are often instructed to allow themselves to fall asleep or not to resist falling asleep. Those who undergo the MSLT are often tested in standardised conditions and in their street clothing and do not have to remain in bed between the test sessions. Patients are also asked not to engage in any vigorous pre-test activity that can alter the outcome of the test. During test conditions the room is often dark and quiet and electophysiologic measures are carried out to detect sleep onset and to score sleep stages. Respiratory flow and sounds in patients who snore will also be recorded. The MSLT is useful for documenting treatment response (Dement, Carskadon and Richardson, 1978; Lamphere, Roehrs and Wittig, 1989 and United States; Modafinil in Narcolepsy Study Group, 1998). The MSLT is also useful in revealing any residual sleepiness in those patients who no longer report to be feeling sleepy after treatment (Zorick, Roehrs and Conway, 1983). The MSLT has a direct, objective and quantitative approach. Prior to undergoing the MSLT the patient will have a full polysomnogram and will be tested to see if sleepiness is pharmacologically induced. The American Academy of Sleep Medicine (AASM) Standards of Practice Committee has published new practice parameters for the clinical use of MSLT (AASM, 2004). These parameters set by the AASM were developed by the basis of a comprehensive evidence-based medicine review process. Other measures of physiological sleepiness Pupillography Pupil stability and size are affected by exposure to light and by an individual’s arousal level. The change in pupil size from pupil constriction to dilation can be reflected in the autonomic nervous system. Change has been researched as a potential measure of sleep tendency (Schmidt and Fortin, 1982). Electronic pupillography is an objective method for monitoring the size of the pupil, but it is difficult to compare individual’s normative data with one another and the technique has not come into general use for clinically evaluating sleepiness. 74 Electroencephalography It has long been thought that EEG delta activity can be used to index sleepiness. Sleep-related EEG delta activity increases in response to experimental sleep deprivation (Borbely, Baumann and Brandeis, 1981). In essence, the MSLT uses EEG markers (macroarchitectural features) of sleep onset to quantify sleepiness. Tests to assess manifest sleepiness Maintenance of Wakefulness Test Mitler and colleagues (1997) have stated that the procedures used to conduct the MWT are similar to those used for the MSLT. The difference between the two tests is the instruction given to the individual, in this case the individual is asked to remain awake. In the case of the MWT the assessment focuses on the individual’s capability of not to be overwhelmed by sleepiness, so in this case the functioning of the underlying wakefulness system is assessed. In the MWT there is no actual task other than to remain awake. During this test an individual is monitored for EEG sleep onset during four to six sessions which is scheduled at two-hour intervals beginning two hours after awakening from the previous night’s sleep. The MWT will also include questions on the effect of acute sleep deprivation, age, time of testing and drugs. The MWT measures often reveal improvement in those patents that have been treated and who continue to be physiologically sleepy. Performance and Vigilance Tests Behavioural or manifest sleepiness can be measured using a variety of performance tasks. Performance and vigilance tests attempt to measure cognitive slowing, such as the digit symbol substitution test, whereas others cover changes in attention. Vigilance tests often tend to mimic the tedious and palling situations of watching for blips on a radar screen or for ships on a horizon. This test is relevant for those patients diagnosed with disorders of sleep and arousal. There are a variety of tests available that measure performance, vigilance and sustained attention. The most common test used in sleep laboratories is the psychomotor vigilance tests which was created by Dinges and colleagues (Kribbs, Pack and Kline, 1993; Doran, Van Dongen and Dinges, 2001). This test employs trials with duration of about tenminutes in which a hand-held computerised display-and-response unit quantifies 75 response latency to multiple light emitting diode (LED) presentations of a stimulus. Data with this inexpensive method has been validated with the Stanford Sleepiness Scale (SSS) and the MSLT. The Oxford Sleep Resistance (OSLER) test is also another performance related test used in sleep laboratory setting and has been validated with the MWT. The OSLER test is based on four forty minute long trials during which there are several LED signal presentations. In this test the patient is asked to respond to each signal with a simple press of a button. Trials usually last forty minutes or if the patient fails to respond to a signal, assuming the patient has missed the signal as he or she has not been able to maintain wakefulness. Introspective Sleepiness Profile of Mood States Although this test is designed to assess mood states it can also be used in sleep research, (McNair, Lorr and Droppleman, 1992). The profile of mood states (POMS) test include a dimension assessing sleepiness, however it was removed as it was found to overlap with other scales. Through extensive research it has been shown that sleepiness loads several POMS scales in particular vigour, which is negative, confusion and fatigue. On the other hand, to a lesser extent sleepiness is associated with increased scores on depression and anger scales. Stanford Sleepiness Scales The SSS was the standard measure of sleepiness (Hoddes, Zarcone and Smythe, 1973). Patients who are given the SSS as a measure of their sleepiness are asked to choose one of seven statements that can describe their self-assessed current state. The SSS is a momentary assessment scale and can detect sleepiness as it changes over the course of the day. The SSS is easy to administer and can be taken repeatedly. Individuals who undergo experimental sleep deprivation score highly on the SSS. There is no normative data available, however, for the SSS, therefore no clinical judgements can be made and it is difficult to compare introspective sleepiness between individuals. 76 Epworth Sleepiness Scale The popularity of the ESS arises from the fact that it is simple to use and the fact that it is validated through various research studies, has ensured that ESS is one of the most commonly used self-reported scales used to assess daytime sleepiness. The problem with the ESS is the question of the usefulness of the test when it is readministered within a certain brief time interval. It is also not useful in evaluating circadian rhythm influences on sleepiness, factor such as sensitivity to age, acute sleep disturbance or deprivation and the reaction to drugs is not known. This questionnaire has been discussed in section 3.2.4 Summary This section has provided an overview of the different methods that are used to assess sleep currently in a clinical setting and in research. Both objective and subjective tests have been discussed and described. It is important to note that the choice of the assessments depends entirely on the aim of assessment; for example, whether it is for research purposes or clinical purposes. This is not to say that other factors are considered to be unimportant, such as age and presence of any specific conditions such as underlying disorders. 77 2.1.6 Treatments for sleep disorders This section will provide an overview of the various treatments available for sleep disorders. Different sleep disorders require different approaches. In this chapter the three approaches described are: medication, other physical treatments and psychological approaches. Only treatments for adults are described in this chapter with emphasis on sleep related breathing disorders because only adults were studied within this programme of research. Medication This section describes the main pharmaceutical treatments used to treat sleep disorders. One of the most common forms of medication prescribed in clinical practice is hypnotics. In the United States, the most frequent clinically used sedatives/hypnotics include five benzodiazepines (“valium-like” compounds); these are available in both proprietary forms and generic forms and two non-benzodiazepines (Zolpidem and Zaleplon) and these are available via prescription. The drugs represent a large market and tend to involve on average 27 million prescriptions that in 2002 were at a value of $1.2 billion; in the same year the same number of nonhypnotics were prescribed for aiding sleep. Trazadone, which is an antidepressant, was one of these drugs prescribed; this alone accounted for 10 million prescriptions (Mendelson, 2005). Hypnotics Hypnotic drugs, also known as soporific drugs, are a class of psychoactives; the primary function of these drugs is to induce sleep and such drugs are also used in the treatment of insomnia (Mendelson, 2005) and in surgical anaesthesia. Drugs that fall within this category are usually dose-dependent and range from anxiolysis to the production of unconsciousness; collectively they are referred to as sedative-hypnotic drugs (Mendelson, 2005). Hypnotic drugs are habit forming and the clinician will usually offer alternatives. If the clinician does prescribe such drugs it is often for a short time. 78 Benzodiazepines These are the best known and often prescribed hypnotic medications at present. There are few studies that have researched the effects of drugs such as lorazepam, nitrazepam and diazepam but those that have studied their uses indicate that they are effective hypnotics (Mendelson, 2005). Studies have shown that 10 milligrams of diazepam both decreases sleep latency and increases total sleep when taken for several days (Mendelson, 2005). There are no studies that have shown the effects of taking ten milligrams of diazepam for longer than seven days. Patients have also reported their preference for diazepam over flurazepam. Diazepam is not officially recognised as a sleeping medication in the United States. Flurazepam is better studied than diazepam. Flurazepam is shown to shorten sleep latency and decrease intermittent awakenings and increases total sleep. It also decreases slow wave sleep. Thirty milligrams of flurazepam decreases the amount or percentage of REM sleep; this does not however decrease the REM density. Nonbenzodiazepines The nonbenzodiazepines are a class of psychoactive drug whose pharmacological actions are similar to those of the benzodiazepines; however, the nonbenzodiazepines are structurally unrelated to the benzodiazepines chemically. Clinical trials of the use of nonbenzodiazepines in the treatment of sleep disorders have demonstrated efficacy (Mendelson, 2005). There is some limited evidence, which suggests that tolerance to nonbenzodiazepines is slower to develop than with benzodiazepines. These data are limited, however and no conclusions can be drawn from them. There are also limited data available on the long-term use of nonbenzodiazepines. Clinically, there is little understanding of how hypnotics actually work. One approach suggests that hypnotics work by altering the perception of sleep and wakefulness (Mendelson, 1990). This arose from the work by Rechtschaffen, who observed that poor sleepers when experimentally aroused earlier than normal in stage 79 2 sleep reported that they had been awake, whereas good sleepers reported that they had been asleep (Rechtschaffen, 1968). Replication of this work by Mendelson in 1993 and 1995 demonstrated that when doses of triazolam or Zolpidem were administered, patents that had been diagnosed with insomnia reported to have been asleep compared to when the same group of patients were given a placebo. Other Physical Treatments Positive pressure devices Nasal Continuous Positive Airway Pressure (CPAP) is the current treatment of choice for the majority of adults with sleep-related breathing disorders. Nasal CPAP has proven to be a very successful treatment. 95% of patients can be definitively treated with this device, including patients with mild disease (Redline, Adams and Strauss, 1998). Nasal CPAP has been shown to improve many aspects of sleeprelated breathing disorders including daytime sleepiness (daytime sleepiness will be discussed in greater detail in section 2.4.5) (Engleman, Cheshire and Deary, 1993) and quality of life (D’Ambrosio, Bowman and Mohsenin, 1999) and patients have fewer hospital stays (Peker, Hedner, Johansson and Benden, 1997). One of the biggest disadvantages of using nasal CPAP is that clinicians had to rely upon the patients report regarding usage. Now, however, CPAP machines contain timers to measure hours of usage and on average it has been found that the apparatus is used five hours per night (Engleman, Martin and Douglas, 1994; Reeves-Hoche, Meck and Zwillich, 1994; Engleman, Asgari-Jirhandeh and Mcleod, 1996). Behavioural Interventions for OSAS Apart from medication and physical treatments that are available, good medical care will also incorporate the patient’s lifestyle. This is necessary to ensure that the patient’s lifestyle does not complicate the underlying medical problems. There are a number of lifestyle considerations that need to be considered which can increase the risk. 80 Weight Loss Obesity can have adverse effects on the upper airway function; this is due to the mechanical influence of the upper airway geometry (Strollo, Atwood and Sanders, 2005). Animal studies have shown that upper airway resistance is usually influenced by mass loading of the anterior neck; this may stimulate the clinical scenario of excessive adipose tissue deposits in this area (Koenig and Thach, 1988). The data provided from animal studies supports the notion that fat deposits around the neck area do appear to cause upper airway resistance and this can be seen in patients diagnosed with obstructive sleep apnoea/hypopnoea syndrome as they have thick necks and the increased circumference is a predictor of obstructive sleep apnoea/hypopnoea syndrome. Smoking cessation Smoking has damaging effects on sleep. Individuals who smoke tobacco usually have difficulty in initiating and maintaining sleep and also report daytime sleepiness (Philips and Danner, 1995). There are a variety of possible explanations for this, including the impact of nicotine withdrawal. This could be due, as well, to the predictable association of smoking and sleep disordered breathing (McCardle, Grove and Devereux, 2000). Smokers are four to five times more likely to suffer from sleep disordered breathing than non-smokers (McCardle, Grove and Devereux, 2000). Those who smoke heavily are at a greater risk. Cigarette smoking may cause upper airway dysfunctions during sleep as it elicits mucosal oedema and increased upper airway resistance (Strollo, Atwood and Sanders, 2005). Sleep Hygiene and Sleep Deprivation We live in a sleep-deprived society (Bonnet and Arand, 1995). The effects of sleep deprivation were discussed in section 2.6.1. However, repetitive sleep deprivation may predispose to or worsen symptoms in patients diagnosed with obstructive sleep apnoea/hypopnoea syndrome. Patients are also encouraged to maintain good sleep hygiene; sadly, this advice is not always maintained and could be due to a number of reasons, ranging through 81 financial pressure and social pressures. It is important for clinicians to encourage patients to maintain their sleep hygiene, as poor sleep hygiene can have an impact on their sleep disorder, which in turn causes their sleep to be of a poor quality. Body Position One of the oldest interventions to prevent snoring in patients with obstructive sleep apnoea/hypopnoea syndrome is for the bed partner to prompt the individual to move to the lateral recumbent position; those who sleep supine have greater sleep disordered breathing events (Cartwright, Lloyd, Lilie and Kravitz, 1985; George, Millar and Kryger, 1988). Upper airway occlusion is increased when sleeping in the supine position due to the effect of gravity on the tongue. Body position is also inversely related to obesity (Cartwright, 1984). Patients who are clinically obese are more likely to suffer from obstructive sleep apnoea/hypopnoea syndrome regardless of body position (Cartwright, 1984). Alcohol Alcohol can increase the chances of upper airway obstruction in individuals who otherwise only snore and also tends to increase the frequency in patients who have been diagnosed with obstructive sleep apnoea/hypopnoea syndrome (Issa and Sullivan, 1982). Alcohol not only increases the frequency of sleep-disordered breathing but it also increases the duration of these events (Gleeson, Zwillich and White, 1990). Alcohol can have an effect, as well, on daytime alertness in those patients diagnosed with obstructive sleep apnoea/hypopnoea syndrome. Psychological approaches Psychological and behavioural treatments are readily available for primary insomnia. Basic sleep hygiene education, psychological and behavioural interventions are one of the few options that are available for patients diagnosed with insomnia. One of the main objectives for employing psychological and behavioural approaches is to target specific factors that perpetuate or exacerbate sleep disturbances. These factors can include poor sleep habits, irregular sleep-wake schedules, misconceptions and excessive worrying about sleep and hyperarousal. It is important to deal with these 82 factors when dealing with the sleep problems (Spielman and Glovinsky, 1991). One of the other goals of treatment is to be able to teach patients self-management skills to cope more adaptively with residual sleep disturbances. Cognitive Therapy Cognitive restructuring therapy works by altering dysfunctional cognitions about sleep. Cognitive therapy works by restructuring the negative thought processes that the patient holds about their sleep, for example when a person is unable to sleep at night they will begin to think about the consequences of their lost sleep on their performance the following day, this then sets off a viscous cycle of insomnia, emotional distress, and more sleep disturbance. Cognitive therapy is designed to short-circuit the self-fulfilling nature of this vicious cycle. Cognitive therapy is useful in the sense to be able to teach patients coping skills to prevent or minimise recurrence of sleep disturbances after treatment. Sleep Hygiene Education This treatment is intended to provide information about the patient’s lifestyle, this being their diet, exercise and substance use if any and environmental factors such as light, noise and temperature which can all interfere with or promote better sleep (Lichstein, Wilson and Johnson, 2000). This treatment includes general sleepfacilitating recommendations, such as teaching the patient to relax before bedtime and providing the patient with information about maintaining sleep schedule. Summary This chapter has shown that there are a wide range of treatments available for those patients who have been diagnosed with a specific sleep disorder. In this chapter pharmacological treatments have been discussed, newer drugs are being developed continuously to improve this form of treatment plan, different drugs behave in different methods, and clinicians will usually tailor a care package for their patient to get the most out of treatment. Treatment can involve more than one treatment plan for example a pharmaceutical intervention along with a behavioural intervention. For those patients with severe upper respiratory tract obstructions, there are a number of surgical options available. Lastly psychological and behavioural interventions have 83 been discussed and once again there are a range of treatment plans to choose from, the clinician or the allied health professional will usually adopt the most suitable care plan for the patient. 84 2.2 Respiratory Diseases Overview This section deals with the aetiology and pathogenesis of obstructive diseases, in particular asthma and chronic obstructive pulmonary diseases (COPD) (emphysema and chronic bronchitis), bronchiectasis and the differential diagnosis of obstructive diseases, the clinical features and tests of pulmonary function and other diagnostic procedures. Introduction Obstructive diseases of the airways are a diverse group, they have one thing in common and that is the narrowing of the airway that results in an increase in the work of breathing. Obstruction can occur in the upper airways as well as the site of the bronchioles. The mechanisms of airway obstruction involved in obstructive lung diseases are quite varied, for example the decrease in maximal expiratory air flow in emphysema is due to the loss of lung elastic recoil secondary to the breakdown of lung tissue and the enlargement of the alveolar spaces, However in chronic bronchitis, which is an inflammatory disease of the airway, the narrowing will occur in the airways themselves. Even so these two diseases are difficult to differentiate clinically and thus in the past clinicians have pooled these two obstructive diseases and have given them the common name of COPD. Another important factor to bear in mind is the difficulty in defining the diseases, for example, chronic bronchitis is defined clinically by the chronic presence of cough lasting longer than 1 month and sputum production. Classifying the various obstructive diseases has its advantages in terms of treatments and prognosis. This is mainly due to the combination of differences due to the signs and symptoms, the various tests used for structure and function, the responses to the different treatment modalities that enable the clinician to deal effectively with the different airway obstructive disease presented. It is important to note that the exact cause of most airway diseases is not very well understood. Research has shown that cigarette smoking is associated with chronic 85 bronchitis and emphysema. Researchers are still puzzled by why cigarette smoking causes lung tissue damage in some people, predominantly chronic bronchitis in others and yet no detectable illness in most people; the same can be said about asthma, the pathologic mechanisms still puzzle us. With the case of asthma, often allergic mechanisms are involved and with many adult asthmatic patients they will not present with allergic symptoms and it is usually these patients who have severe asthma. 86 2.2.1 Asthma Definition Clinically physicians are confident in their ability to recognise the symptoms of asthma. Nevertheless, agreement on a definition of asthma has proved to be difficult (Davis, 1996). Difficulty has arisen from the early definitions of the disease and the overreliance on the characteristics of physiologic abnormality. Definition of any disease is most satisfactory when it has been derived from the identification of a discrete single causative agent or from detection of a characteristic pathologic abnormality (Boushey, Corry and Fahy, 2000). Due to the fact that there has been no single agent identified which can be a central causal component and no pathologic feature is unique to asthma, the disease has been more described than defined (Boushey et al, 2000). Some of the symptoms of asthma are shared with diseases of other systems. Even if the symptom of breathlessness is thought to be due to lung disease, there are numerous relatively common lung diseases and differentiation of an airway disorder needs to be made from both infections and pulmonary thromboembolic disease and restrictive lung disorders (Thorax, 2003; p. 13). The British Guidelines on the Management of Asthma also states within Thorax the respiratory journal that any features of an airway disorder such as cough, wheeze and breathlessness should be confirmed where possible by measurement of airflow limitation. These symptoms could present either due to a localised airway obstruction for example a foreign body or perhaps a generalised issue such as asthma. Such attempts to define asthma have been made over a number of years to establish an unambiguous definition of the disease that is recognised as asthma. An early definition prior to The British Guidelines on the Management of Asthma was provided from a Ciba symposium in 1959 and referred to asthma as a condition that varied spontaneously either with time or in response to therapy (Ciba Guest Symposium, 1959). The definition applied by Ciba does apply to many patients but it 87 raises the question of how much variability is needed before the diagnosis can be made and what are its acceptable limits. Other attempts to define the disease have been made as a result of various international symposia and consensus reports (American College of Chest Physicians/American Thoracic Society, 1975; International Asthma Management Project, 1982). More recent attempts to date have incorporated the concept of bronchial hyperactivity; nonetheless, this does appear in other conditions, too, so it cannot be used as a single entity to define asthma. From this, a consensus definition for asthma has been developed that recognises this disorder to be a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role; those which play a central role are mast cells, eosinophils, T lymphocytes, neutrophils, and epithelial cells. In individuals who are susceptible to such a disorder, the inflammation that is present will cause recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly at night and/or in the early morning. Such episodes of inflammation are present due to the widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment. The inflammation also tends to cause an associated increase in the existing bronchial hyperresponsiveness to a variety of stimuli (Lemanske et al, 2003). Risk factors Those studies conducted with adults have looked at factors weakly associated with asthma: male gender, low birth weight, prematurity, maternal smoking in pregnancy, parental smoking, and high intake of salt (Wilfond and Fost, 1990; Barasch et al, 1991). Factors such as family size have also been investigated (Riordan, 1999; Denning et al, 1992) and consumption of oily fish (Gregory et al, 1991). Work conducted by Kalin et al (1999) has shown that there is no primary prevention study that has shown that reduction of any identified risk factor, even house dust mites, did not significantly reduce asthma prevalence but larger trials are now underway. There are various factors associated with the onset of asthma; symptoms such as an ordinary cold often precede asthma exacerbations. Asthma has also been suspected of having a strong genetic component at least since 1860, when Henry Salter stated 88 that he found “distinct traces of inheritance...in two cases out of every five” (Salter, 1864). What is asthma? So what exactly is asthma? Asthma is known to be a chronic condition that primarily tends to affect the air passages in the lungs and at present there is no cure. The classic symptoms of asthma that a patient presents upon examination are usually breathlessness, tightness in the chest, cough and wheezing. The airways in the lungs are usually characterised by inflammation and an increase in irritability, these two presenting symptoms is what causes the airways to narrow and therefore has a knock on effect on the other presenting symptoms in asthma. This tends to happen variably but is maybe worsened by triggers such as infection, exercise and allergens. Inflammation can reverse spontaneously or in response to treatment, episodes of asthma attacks can be severe. Death from asthma is uncommon. Airway narrowing can be due to mucus in the airways of the lungs, swelling of the lining of the airway, or to spasm of the muscle in the walls of the airways or a combination of all three. Recognising asthmatic symptoms Those who live with the disease will usually describe the disease process very differently to what would be written in a medical textbook. Describing the sensations experienced with any disease to someone who does not live with it is usually difficult. Most of the time we are unaware of our breathing except during physical exertion where even a small amount of shortness of breath can affect the physically fit. During exercise, breathing is more deep and rapid, there is a certain rawness in the chest, which occurs due to the drying up the surface of the air passages and this can be relieved by breathing moist air, this sensation is not however unpleasant, however, until the point of exhaustion is reached there is usually a feeling of satisfaction that the breathing is meeting the demands of the body, although this is not the case with asthma. When there is bronchial narrowing this slows the movement of air into and out of the lungs. There is difficulty in breathing in and breathing out. The individual will require more effort to achieve an adequate airflow, which means greater effort intrudes itself into the consciousness. The greater the effort is required the more there 89 is a sense of difficulty in breathing which is very unpleasant and frightening. The breathing difficulty experienced by an asthmatic patient is qualitatively different and therefore requires a different set of descriptive words; common words that are used to describe such sensations are tightness, congestion and wheezing (Lane, 1987). Like many words used to describe the symptoms, ‘congestion’ means one thing to the sufferer and another thing to the clinician. The medical world has a definition for almost every symptom but congestion to the patient basically means the individuals chest filling up with phlegm and that it needs to be cleared (Lane, 1987). Patients try to put into words the sensations of wheezing and distension of their lungs. A New Zealand physician who had been a lifelong asthmatic remembered describing this sensation as a child in these words: ‘It’s just as if your chest had been blown up with a bike pump and then put into an iron clamp.’ (Lane, 1987). The pattern of asthmatic symptoms The symptoms that the asthmatic patient presents clinically do not help to recognise asthma so much as the circumstances in which they occur. Most of the symptoms that occur in asthma are also present in other chest diseases; in asthma, however, they occur in seizures. These could be brief episodes of wheezing, which can last up to an hour or so, merging into a full-blown asthma attack. The asthmatic patient will also recognise that his/her lungs are sensitive to the weather; this can be apparent especially during the cold winter months, when there can be tightness and a momentary shortness of breath. The change from a cold environment to a warm dwelling can also produce similar sensations. There can be but not necessarily sensitivity to certain products such as perfume, petrol, wood, smoke and cigarettes. Violent movements of the chest such as coughing and laughter can also bring on a sudden paroxysm of wheezing. Such details may demonstrate the extreme sensitivity of the asthmatic patient’s airways to irritant stimuli. These sensations are not an attack in itself, just brief episodes. A prolonged episode of wheezing would need to be triggered by a stronger stimulus, such as exercise. For all patients with asthma, especially those with adult onset asthma, there is a history of an extremely rapid progression of symptoms (Wesserfallen et al, 1990; Benatar, 1986) and a history of anaphylactic sensitivity to certain foods, such as nuts 90 and shrimps for certain patients (Sampson et al, 1992; Kemp et al, 1995), ingestion of aspirin or foods likely to contain sulphites (dried fruits, restaurant salads) as these can provoke severe life-threatening attacks in patients who otherwise have features of mild or moderate asthma (Samter and Beers, 1968). The asthma attack Aretaeus, an ancient Greek physician who practised in the 1st century CE described the symptoms of the attack as: ‘The symptoms of its approach are heaviness of the chest; sluggishness to one’s accustomed work’ (Lane, 1987). There are changes in mood, irritability that is difficult to rationalise, coupled with depression or apprehension; there is also a forced gaiety in mood of a few, prior to the commencement of wheezing, and coughing. The cough is irritating and nonproductive. Skin irritation may also persist in some patients, Lane (1987). During the height of the attack, psychological symptoms of distress, anxiety will be experienced, speech is impossible and the patient will usually be gasping for breath, with beads of sweat forming on the brow which is present in severe cases. Speech is impossible; feelings of restlessness and fright are also present. Asthma attacks do sometimes settle spontaneously; during the present time they can be aborted with medication and there are only a few that persist to the descriptions set out by Aretaeus: ‘If these symptoms increase, they sometimes produce suffocation after the form of epilepsy’ (Lane, 1987). Once the main attack has subsided, the sense of distension is the first to go, breathing becomes easier, the wheeze remains and there may be an increase in the loudness of airflow. Secretions are released; the phlegm is clear or white and may contain pellets or strands which have a branched appearance that may have been trapped in the smaller bronchi and have been released during the attack. After the attack the tension is relaxed and mood elevates. The individual will usually want a drink and have great hunger and want rest. The asthma attack itself is the hallmark of asthma. 91 Pulmonary Function Testing There are characteristic changes that can be seen once a pulmonary function test has been performed between attacks or even after long periods of remission. Reductions in maximal expiratory flow are the easiest to detect Tests of peak flow are dependent upon effort, however they can be reliable if performed on a cooperative patient and can be repeatedly measured with any several lightweight, portable and inexpensive devices which meets the criteria set out by the American Thoracic Society (ATS) for accuracy (ATS, 1995). The monitoring of ambulatory patients is the best use of peak flow in such patients; changes in peak flow can serve as a guide to patients for adjusting treatments (Lahdensuo, 1996). Calculations of peak flow variability are also a good guide to use to detect abnormal airway lability as an indirect measure of bronchial responsiveness (Ryan et al, 1982). Peak flow is determined by the diameter of central airways, it is less sensitive to changes in peripheral airways than are measurements of flow at lower lung volumes. Such flows contribute to FEV1, which explains why peak flow underestimates FEV1, by 10% to 20% in 30% to 50% of asthmatics (Ritchie, 1962; Meltzer et al, 1989). FEV1 (the volume of air expired in the first second of a forced expiratory manoeuvre from total lung capacity) is the best-standardised and most widely used test to measure airflow obstruction. The hallmark of asthma is an improvement in FEV1 of more than 12% and more than two hundred millilitres after the administration of a bronchodilator (American Thoracic Society, 1995). Interpretation of scores of an FEV1 usually requires simultaneous measurement of the forced vital capacity (FVC), which tests the total volume exhaled from total lung capacity (TLC) to residual volume; the reduction in FEV1 exceeds the reduction in FVC and therefore the ratio of FEV1/FVC is low in asthma. This is however not the same in severe asthma, where the residual volume is increased so that the reduction in FVC is proportional to the reduction in FEV1. Studies have shown that treatment may reverse the narrowing of the peripheral airways which will then allow exhalation at a greater volume before airway closure occurs, therefore allowing the improvement in FVC to be greater than the improvement in FEV1 (McFadden and Lyons, 1969). 92 Other factors which contribute towards the prevalence of asthma Ethnicity Ethnic origin plays a major part in the epidemiology of many important chronic diseases and therefore it is pertinent to consider what effect, if any, it has in asthma. Within the United Kingdom (UK) work conducted in Blackburn (1987) studied the clinical situation that asthma admissions among ethnic Asian adults were more frequent than expected, which concluded that the rise was not due to the readmissions, this was then revisited during the early nineteen nineties when exactly the same findings were produced. The authors stated that this was perhaps due to the fact that asthma prevalence was higher in this group or that cultural factors might explain the observed difference. Work conducted in Southampton during the late nineteen eighties compared the prevalence of asthma amongst Asian and European children. It was suggested that differences found amongst the two were due to the prevalence reported from primary care which might result from either more severe or less adequately treated asthma among Asians or from a lower threshold for seeking medical attention in this group. The latter point is supported by data from a study in London in the early nineteen nineties which highlighted the risk of under-diagnosis and under-treatment was higher for Asian children. It has been suggested that it might be more common for foods such as fizzy drinks, fried foods and nuts to act as a trigger to asthma in Asians; it is unclear whether or not this is due to the fact that perhaps Asians tend to eat this particular food more frequently than other ethnic groups. Summary Asthma is a chronic long-term condition that affects the airways. Patients who have been diagnosed with asthma tend to have over-sensitive, narrow and inflamed airways; this usually makes it difficult for the patient to breathe. Although asthma is a serious condition, it can be well controlled with the right care plan. Common symptoms include a cough, wheeze, shortness of breath and tightness in the chest. The likelihood of a patient being diagnosed with asthma is increased if the symptoms are variable and unpredictable, intermittent and especially if they are worse at night. Environmental pollutants and pets, exercise and viral infections and chemical 93 pollutants such as chemicals and tobacco smoke can often trigger symptoms. Diagnosis is usually first made by the patients family GP after a series of tests and investigations which measure the volume and speed of air that the patients can breathe, expire and inspire. A patient can be referred to a specialist if the GP cannot control the patient’s disease. Treatment plans usually include the patient achieving control of their symptoms. Treatment plans are usually tailored to the patient according to the patient’s lung function test. 94 2.2.2 Chronic Obstructive Pulmonary Disease Introduction In the early twentieth century tuberculosis (TB) was the major pulmonary disease occupying the work of physicians. In the latter part of the twentieth century the two main pulmonary diseases that have taken over from TB are now carcinoma of the lung and COPD. The death rate trend of these two conditions is very similar. The prevalence of COPD, however, including both chronic bronchitis and emphysema with their symptoms of cough, expectoration, wheezing and laboured breathing is higher. Definitions COPD According to Snider (2003) it is important to be able to differentiate between the definition of a disease and its diagnostic criteria. The common properties specifying the group of abnormal persons are the defining characteristics of a disease and on whom the description of the disease is based. A number of expert panels which include The American Thoracic Society (ATS), the European Respiratory Society (ERS) and The British Thoracic Society have all defined COPD slightly differently over the last ten years or so (Snider, 2003). The Global Initiative for Chronic Obstructive Lung Disease (GOLD) and an expert panel that was joined by the National Heart, Lung and Blood Institute and the World Health organisation have produced a report and have defined COPD as: A disease state characterised by airflow limitation that is not fully reversible. Airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. www.goldcopd.com (Accessed on 20th April, 2007). Chronic bronchitis and emphysema may occur with or without airflow limitation, whereas asthma by definition (ATS, 1962) is always associated with discernible airflow limitation. According to the frequent etiological factors associated with 95 chronic bronchitis and emphysema they often occur together (Burrows, 1987). With asthma, however, which is a disease whose hallmark is reversible airflow limitation, can lead to fixed airflow limitation (Peat et al, 1987; Lange et al, 1998). Clinically, these three diseases are often similar physiologically and therefore any precise classification of the patient’s disease is often difficult. To overcome this problem a variety of terms have been developed to use synonymously for patients who evidence one or more of the diseases and these are: chronic obstructive airway disease, chronic obstructive lung disease and, of course, COPD. It is difficult to define COPD so it has been agreed that COPD should only be used for patients who present with airflow limitations that have been ascertained objectively. According to Higgins (1991) chronic bronchitis and emphysema may present without much evidence of airflow limitation. The definition of COPD has evolved over time from one being based on a clinical diagnosis of chronic bronchitis or anatomical findings of emphysema to one based on the presence of abnormal lung function (Pauwels et al, 2001; Snider, 2003). The GOLD criterion have been used to classify the severity of the obstructive lung disease, which has been adopted by the ATS as well as the ERS. The criteria are classified on the basis of postbronchodilator lung function into various categories, as shown: The GOLD criteria for classifying obstructive lung disease on the basis of postbronchodilator lung function. Stage 0 (at risk) FEV1/FVC ≥ 0.70 and FEV1 ≥ 80% predicted and symptoms of chronic bronchitis, Stage 1 (mild): FEV1/FVC < 0.70 and FEV1 ≥ 80% predicted, Stage 2 (moderate): FEV1/FVC < 0.70 and FEV1 < 80% predicted and FEV1 ≥ 50% predicted, Stage 3 (severe): FEV1/FVC < 0.70 and FEV1 < 50% predicted and FEV1 ≥ 30% predicted, Stage 4 (very severe) : FEV1/FVC < 0.70 and FEV1 < 30% predicted. Chronic Bronchitis The American Thoracic Society (ATS) (1962) and the Ciba Foundation Guest Symposium (1959) have stated that chronic bronchitis should be defined in 96 epidemiological terms as the presence of a chronic productive cough for 3 months in each of 2 successive years in a patient in whom other causes of chronic cough, such as infection with mycobacterium tuberculosis, carcinoma of the lung, bronchiectasis, cystic fibrosis and chronic congestive heart failure have been excluded. For the ease of clinical purposes, chronic bronchitis can simply be defined in a patient who presents with a chronic productive cough without a medically discernible cause which may be present for less than 2 years. Although this is a simpler definition to use clinically there are problems with the fact that patients may present with similar symptoms if they have a chronic irritation induced by inhaled substances. Recognising COPD symptoms History Cough is the most frequent symptom that is reported by patients who present with COPD. This particular symptom precedes the onset of dyspnoea and sometimes this occurs at the same time for most patients. Although patients who are diagnosed with COPD do manifest cough, expectoration and dyspnoea, it is usually the dyspnoea that causes them to seek medical attention. The coughing in this case does not usually interfere with day-to-day activities and usually the patient if often unaware of the cough. According to Seemungal (1998) the use of a cough suppressant for a chronic productive cough is believed to lead to retention of secretions; a daily cough is predictive of frequent exacerbations. With regards to sputum production, this is usually quite insidious in its onset and in most patients it is ‘scanty’, defined as less than several tablespoons per day. Clinically assessing COPD During a physical examination of some patients with COPD there is little abnormality revealed, especially during quiet breathing. Although coarse crackles early in inspiration may be present, this has been usually associated with obstructive lung disease; other sounds may be present, too. For example rhonchi are more prevalent in patients who complain of dyspnoea and this is usually presented during both inspiration and expiration. With regards to wheezing this is not usually a consistent finding and therefore cannot be related to the severity of the obstruction. The most objective and consistent finding in patients with symptomatic COPD is the 97 prolonged expiratory time; this is best determined by listening over the larynx during a forced expiratory manoeuvre. If the expiratory phase is longer than the normal 4 seconds than this is indicative of a significant obstruction. As the severity of the COPD increases, patients begin to demonstrate more apparent physical changes and signs. These are barrel shaped chest, pursed lip breathing, emaciation and usually inguinal hernias which may appear in some. Patients will also display the position of tripodding, which is usually where patients can be observed sitting forward and leaning on their elbows, or supporting their upper body with extended arms. This position is usually adopted to maximise intrathoracic volume. From another perspective, pulmonary hypertension may also be noted with a loud pulmonary component of the second heart sound; this is due to the fact that heart sounds maybe displaced to the middle due to hyperinflation. Computed Tomography (CT) CT scans can be used to further determine a diagnosis much better than the traditional chest radiographs. CT scans also be used to quantitate the amount of air trapping by a comparison of images during inspiration and full expiration (Knudson et al, 1991). Pulmonary Function Test These measurements serve to assess the severity of airflow limitation, which quantifies the presence of the various abnormalities and to be able to identify and quantify reversible airflow limitation. Pulmonary function tests are helpful in documenting the progress of disease and in making a prognosis. With airflow limitation there is the development of a systemic dysfunction and impairment of gas exchange and this is one of the most significant functional defects in chronic bronchitis and emphysema. In emphysema there is a loss of elastic recoil this then allows the collapse of distal, poorly supported airways at much higher lung volumes than normal. This leads to the increase in pleural pressure during active expiration by the patient which then worsens the collapse of the distal airways and may give rise to dynamic narrowing of the trachea and large bronchi as the gradient between the extraluminal and intraluminal pressures indent their soft posterior walls (Stevens et al, 1969; Beck and Heiner, 1981). Peripheral airway narrowing from luminal mucus, 98 fibrosis, and inflammation of the walls and from increased smooth muscle is related to airflow limitation (Cosio et al, 1978). The FEV1 test cannot distinguish between these lesions. Due to the loss of elastic recoil of the lung which none of the sensitive parameters of airflow obstruction can be derived from the single-breath nitrogenbreath nitrogen curve, the frequency dependence of compliance, or the density dependence of maximum expiratory flow, is specific for peripheral airway disease. Forced Expiratory Spirometry This is one of the most useful tests of airflow dynamics. According to West (1998) various indices can be determined from the volume time record, one of the few being the volume expired in the first second (FEV1), the flow in the first one fourth of the FVC (FEF0-25) or the middle half of the FVC (FEF25-75), and the peak expiratory flow (PEF) during forced expiratory effort. The PEF and the FEF0-25 are mostly based on effort. The FEF25-75 is relatively effort independent. Maximal flow is largely volume dependant, so therefore when flow limitation is severe, ventilation can be maintained only by prolongation of expiratory time or increasing the lung volume. Maximal flow and ventilation are characteristic of COPD. PEF can be measured with peak flow meters inexpensively whereby patients are usually taught. The other parameters, FEV1, FVC and PEF rate can be measures by using portable pneumotachographbased spirometers that are now readily available. During exacerbations the PEF rate and FEV1 cannot necessarily be determined by portable equipment. The FEV1 has less variation and is more accurately predictable from age, sex and height than the FEF0-25. The FEV1/FVC ratio is poorly maintained in patients with obstructive lung disease but can be maintained or increased in those with restrictive lung disease, making it an important differential point. FEV1 and the FEV1/FVC ratio tend to fall progressively in patients with COPD and they also tend to have limited improvement in airflow in response to a bronchodilator although airflow usually does not normalise. According to Anthonisen et al, (1986) repeated testing increases the number of patients with reversibility. Lung Volumes Total lung volume is increased in emphysema. This is due to the loss of elastic recoil which permits the inspiratory muscles to stretch the lungs to a greater maximal 99 volume. There are variations in the pattern of lung volume abnormality which can be observed in some patients these patients tend to have a markedly increased total lung capacity with a relatively well-maintained vital capacity with marked increases in residual volume. Some patients may reveal a near-normal total lung capacity with greater decrease in vital capacity and a modest increase in residual volume (Burrows et al, 1986; Burrows et al, 1989). These differences tend to disappear as the disease becomes more severe. Sputum Examination Those patients diagnosed with bronchitis and who are stable tend to have sputum which is rather viscid. However during an exacerbation the sputum will become grossly purulent. There are usually several cultures present upon examination of the sputum, various tests such as the Gram stain usually shows certain cultures that can demonstrate the presence of certain organisms. These cultures provide only qualitative data as they are usually found in the URT. However according to Chodosh (1985) the number and type of organisms observed in a culture specimen can help guide physicians in delivering appropriate antibiotic therapy and therefore selecting the most appropriate drug. Snider et al, (1992) have shown that cultures and Gram stain are rarely necessary for instituting antimicrobial therapy unless the patient who is receiving it has had an exacerbation during or soon after receiving a course of antibiotics. Treatment Overview Patients diagnosed with COPD can be managed in an ambulatory setting except for when they have experienced an exacerbation that can give rise to the development of acute respiratory failure. This particular type of therapy can be classified into three categories; specific, symptomatic, and secondary, the latter is based on whereby the therapy improves the whole person without affecting lung function. Specific Therapy There is little available in the way of directed therapy. Evaluation of occupational and other environmental inhaled irritants should be evaluated carefully and dealt with 100 as circumstances dictate. Those patients aged over 65 years and usually with known conditions are usually given an annual dose of the influenza vaccine and then a booster after every 5 years. This then prevents the serious pneumococcal infections in COPD patients but again this still quite controversial. Smoking Cessation Smoking is one of the important cofactors in the cause of COPD and since the government issued its Smoking Kills White Paper on Tobacco during the late 90’s to help the population to stop smoking, every effort should be made to help the patient to stop; this should be particularly important if the airflow is mild to moderate. There are services that patients’ physicians can utilise to help their patients to quit. Services of smoking cessation now run within the community in local pharmacies, GP surgeries and community groups and hospitals. Development of New Therapeutic Initiatives The concept that lung function maybe restored after its loss is also undergoing reassessment. All studies that have been designed to improve natural history of COPD face a common problem, because the progression of the disease is slow, a relatively long time is needed to demonstrate any reduction of that progression (Auerbach et al, 1972). As well, any changes observed will be relatively small, especially if the findings are compared to other physiological measures used to assess COPD, such as Spirometry. Anthonisen et al (1991) has pointed out that due to this if studies were to be conducted then more than 1000 patients would need to be selected for any statistical test to have adequate statistical power. This has led to the thought that more responsive measures of outcome in COPD are needed urgently. Measures such as a high resolution CT scan, QoL assessments and measures of surrogate markers of inflammation by histology induced sputum measures and exhaled air analysis. It is hoped that these measures will help to prevent the progression of emphysema in those who have the beginnings of the disease but are unable to stop smoking. 101 Other factors which contribute towards the prevalence of COPD Gender, Race and Socioeconomic Status Sherrill et al, (1990) have reported that most population studies have shown a higher prevalence of respiratory symptoms in men than in women, even when data have been controlled for smoking. Burt et al, (1994) additional data became available with the publication of the Third National Health and Examination Survey. Rates of mortality in COPD are higher in whites than in nonwhites but this difference is decreasing over time among men (Higgins et al, 1990). Higgins et al, (1990), Sherrill et al, (1990) and the US Surgeon General (1984) have reported that morbidity and mortality rates are related inversely to socio-economic status (SES), measured by the level of education and income. Generally, it is higher for blue-collar workers than for white-collar workers. Faling et al, (1993) have stated that COPD may aggregate in families. Tobacco Smoking This has been established as one of the firmest risk factors for COPD. Longitudinal, cross-sectional and case-control studies have shown that cigarette smokers compared to non-smokers have higher death rates from chronic bronchitis and emphysema. Cigarette smokers also have a higher prevalence for, and incidence of, chronic bronchitis, emphysema and obstructive airways disease and higher frequencies of respiratory symptoms and lung function abnormalities than non-smokers. Smokers also have a greater decline annually in FEV1. Occupation Population studies that have been based on measures of mortality and morbidity have suggested that occupations where the atmosphere is polluted with chemical fumes or non-hazardous dust give rise to an increased prevalence of chronic airflow obstruction and an increase in the rate of decline of FEV1. Occupations such as farming or working within dusty occupations are said to increase the risk of developing chronic bronchitis twofold to threefold; coupled with smoking this increases to six fold (Frost et al, 1994; Melbostad, 1997). Although being exposed to some materials may be very hazardous, most studies have shown that cigarette smoking is still a much greater a risk compared to occupational hazards. 102 Summary COPD is a term used to for a number of chronic airway conditions, these being chronic bronchitis and emphysema. COPD leads to damaged airways in the lungs that causes them to become narrower which makes it harder for air to leave and enter the lungs. One of the most common causes of COPD is smoking; patients who do not smoke are often advised to quit smoking. There are occupational factors such as coal dust, genetic factors such as inherited problems and environmental factors such as pollution that contribute towards COPD. The symptoms of COPD often include cough, phlegm and shortness of breath. Spirometry can best confirm a firm diagnosis of COPD. Further tests and referrals can be made available to those patients who are difficult to diagnose. COPD can contribute towards feelings of anxiety because of breathlessness. COPD cannot be cured but the treatments available to help relieve the symptoms include stopping smoking, as mentioned earlier, patients eating a well balanced diet, remaining mobile, using bronchodilators and sometimes using antibiotics and steroids. Oxygen therapy is also an option. Other factors that may contribute towards the severity of the symptoms include occupational factors, gender, race and the patient’s socio-economic status, too. 103 2.2.3 Bronchiectasis Introduction The term bronchiectasis is derived from the Greek words broncos, “windpipe,” and ektasis, “stretching” or “extension” (Baum et al, 1983). This refers to an abnormal dilation of the proximal medium-sized bronchi greater than 2mm in diameter that has been caused by destruction of the muscular and elastic components of their walls. Usually this dilation is associated with chronic bacterial infection and the production of large amounts of foul smelling sputum. Bronchiectasis is not always associated with purulent expectoration; sometimes when it involves areas of the lung with dependent drainage, such as the upper lobes, which are usually involved in patients with pulmonary tuberculosis (TB). In these cases the bronchiectasis is referred to as dry, which is to distinguish it from the more common wet or productive variety. Lander in 1946 showed that bronchial dilation might be temporary, as it occurs in areas of atelectasis after acute pneumonia. A study by Pontius in 1957 showed that complete reversal of bronchiectasis after several years is possible. Even so, bronchiectasis is generally thought to be a persistent if not a permanent pathological process. Clinicians tend to use the word process to describe bronchiectasis because they stress that bronchiectasis is not a discrete disease entity unless it is solely caused by bronchial obstruction or untreated infection. It is usually more commonly referred to as a pulmonary manifestation of systemic disorders, disorders such as cystic fibrosis and primary ciliary dyskinesia. Fraser et al, (1965) have stated that bronchiectasis is a focal process compared to chronic bronchitis, which is not, as it involves the entire lung. Bronchiectasis can result from local airway obstruction and infection and therefore may be confined to one area. This was probably not true prior to the development of antibiotics; however, because before the advent of antibiotics bronchiectasis was still often generalised. Patients whom have been diagnosed with chronic bronchitis usually do still have some bronchial dilation as do patients diagnosed with bronchiectasis may 104 show changes pathologically especially if they smoke (Heard et al, 1979). There the two conditions tend to overlap quite significantly (Mysliwiee, 1999). Recognising bronchiectasis symptoms Patients diagnosed with bronchiectasis may display symptoms referable to the bronchiectatic process alone or to underling disorders. Symptoms include chronic cough, purulent expectoration, fever, weakness and weight loss. Sputum production often increases during acute respiratory infections. Bronchiectasis can be classified into mild, moderate and severe categories developed by Ellis et al, (1981). Although dyspnoea is not a universal finding, reported only by some patients, dyspnoea may relate more to those with chronic bronchitis and pulmonary emphysema than to pure bronchiectasis (Ellis et al, 1981). Breathlessness is also a common symptom. The effect of cigarette smoking and the presence of severe airflow obstruction on pulmonary function testing may correlate better with subjective complaints than with the extent of bronchiectasis. Baum et al, (1966) highlighted that haemoptysis is also common; it is said to be less common amongst patients with wet bronchiectasis than amongst those with dry bronchiectasis, including those patients diagnosed with pulmonary tuberculosis. Haemoptysis is generally mild and it often consists of the expectoration of purulent sputum flecked with blood. The bleeding usually originates from bronchialpulmonary anastomoses under systemic pressures. Clinically assessing bronchiectasis Diagnosis The disease maybe suspected on the basis of clinical presentation, especially if the process involves purulent expectoration and especially if disorders such as pneumonia, emphysema and lung abscess have been ruled out. The onset of bronchiectasis may be traced back to a clear-cut aspiration or febrile illness, especially in those patients with postobstructive or infectious bronchiectasis. In those patients where bronchiectasis occurs due to underlying disorders such as cystic fibrosis or primary ciliary dyskinesia is more likely to have an insidious onset but may be associated with discrete infectious episodes as well. 105 Clinically, sputum analysis should reinforce the diagnosis of bronchiectasis. Analysis of sputum usually include a visual inspection of the expectorated sputum which has been allowed to settle into the characteristic three layers, an upper frothy and watery layer, a middle turbid and mucopurulent layer and a bottom layer that is purulent and opaque (Sepper et al, 1995). Firm diagnosis of bronchiectasis is usually made by roentgenographic studies. Chest roentgenograms have not been shown to be useful in distinguishing chronic bronchiectasis in patients with cystic fibrosis from acute exacerbations of the disease (Greene et al, 1994). Bronchography a technique that is now completely obsolete but was once used to determine the presence of bronchiectasis. This procedure could be performed with the installation of contrast material via a catheter or bronchoscope. Although bronchography provides adequate visualisation and it is a safe procedure to use, it can be dangerous in patients who have respiratory compromise (Richman-Eisenstat et al, 1993). Bronchography has been replaced by High Resolution Computed Tomography (HRCT) scans of the chest, as they involve little discomfort and have few adverse complications (Lynch et al, 1999). Bronchoscopy is less helpful than bronchography or HRCT for visualisation of the entire bronchiectatic segments. Bronchoscopy is usually useful for detecting aspirated foreign and other obstructing lesions. Treatment The introduction of antimicrobial drugs 40 years ago has been the mainstay of treatment for bronchiectasis. The choice of the drugs is usually dependable upon sputum, bronchoalveolar lavage fluid culture for aerobes, anaerobes and mycobacteria whenever possible. If there is mixed flora present then often a broadspectrum antibiotic is given to the patient to identify a specific pathogen (Ramsey et al, 1996). Most clinicians prefer to give broad-spectrum antimicrobial agents during acute worsening of the condition; some clinicians tend to prescribe such agents on a regular basis. 106 Other treatments include chest physical therapy with postural drainage, chest clapping, humidification, the use of mucolytics and other measures have also been recommended, Mortensen et al (1991). Techniques such as chest clapping can be administered by family members and is said to be of psychological benefit, however the physiologic utility has not been well demonstrated, however when a metaanalysis conducted by Thomas et al, (1995) showed that chest physical therapy resulted in significantly greater sputum expectoration than no treatment, whereas therapy and exercise were associated with a significant increase in expiratory flow rates. A new approach to treat bronchiectasis is anti-inflammatory therapy. Long-term mechanical ventilation, including that administered by facemask, may be useful in patients with bronchiectasis and sever chronic respiratory failure (Benhamou et al, 1997). In addition to the above-mentioned therapies there are also specific therapies that maybe appropriate when the underlying cause of bronchiectasis has been identified. Although medical management of bronchiectasis should prove to be successful, consideration should also be given to surgical resection in certain instances. The first ever, wholly successful surgical resection was carried out in 1901. It should also be mentioned that double-lung and heart-lung transplantation is also available for some patients who have severe generalised bronchiectasis (Scott et al, 1988; Whitehead et al, 1991). Prevention Prevention involves the administration of vaccines against measles, pertussis, influenza and other infections that may predispose the person to bronchiectasis. It also includes the prompt removal of foreign bodies and obstructing lesions in the airways and aggressive use of antibiotics for further bacterial bronchopulmonary infections. This also highlights the need for further research into the systemic disorders which are associated with bronchiectasis in many patients. Summary Bronchiectasis is a permanent abnormal dilation in one or more of the bronchioles. Extra fluid is usually collects in the areas that have been dilated and is prone to infection. The extent to which damage occurs in the airways in patients diagnosed 107 with bronchiectasis is varied. Those areas that are widened are damaged and inflamed. The cause is often not clear and in almost half the cases. Conditions that often contribute towards bronchiectasis are diseases such as TB, inherited conditions, inhaled objects and other inflammatory diseases such as rheumatoid arthritis. Patients presenting with bronchiectasis usually have symptoms such as sputum production, feeling tired, poor concentration, wheeziness, breathlessness and recurring chest infections. Diagnosis is usually confirmed through a CT scan, other tests may be used if an underlying cause is suspected. Treatments often include antibiotics, physiotherapy, a steroid inhaler, immunisation, bronchodilators, stopping smoking and in some cases surgery. There is lack of published research within this area that considers the psychological symptoms associated with this disease. There is also no research that has investigated patients sleep quality, QoL, mood or how cognitive functions can be affected too. 108 2.1.4 Asbestos related conditions Historical background Asbestos is an ancient mineral exploited by humans from prehistoric times because of its properties of durability and heat resistance and its fibrous nature, which enable it to be spun (International Labour Office, 1997; Rom, 1998; Harber et al, 1995). The Finns used asbestos in the fashioning of pottery as early as 2500 BC; the Vestal Virgins in Rome used it for the wicks of their oil lamps and Marco Polo was said to have marvelled at the fire-resisting cloth made by the Chinese during his travels through Asia. Commercial use of asbestos began in the 19th century, starting in open pit mining and grew as mechanisation replaced hand cobbing (International Labour Office, 1997; Rom, 1998) and growth was exponential between the two world wars. Production peaked at more than 5 million tons per year in 1976 and stabilised at approximately 4 million tons per year in the early 1980’s, faltering only in the latter part of that decade when the ill health effects of exposure became a matter of increasing public concern (International Labour Office, 1997). During the 1980s the use of asbestos decreased in Europe and North America, the use of substitutes increasing proportionately (since 1999, the use of asbestos has either been completely banned or severely restricted). However, on the Asian, African and South American continents asbestos continues to be in demand as a cheap and durable material for use in water reticulation and in housing projects. Asbestos is originally a Greek word meaning “unquenchable” (Harber et al, 1995). Currently, it is used as a collective term for naturally occurring mineral silicates of the serpentine and amphibole group. Despite different origins and physical and chemical properties, these silicates have in common a fibrous habit, that is, they occur naturally in bundles of parallel, radiating, or interlaced fibres that usually can be separated readily. The term fibre is of more than pedantic use, because the fibre particle dimensions are determinants, probably important ones, of biologic potency. The non neoplastic effects of exposure to asbestos can be classified into: circumscribed pleural plaques (CPP), diffuse pleural thickening (DPT) and benign asbestos pleural effusion (BAPE). 109 Pleural Plaques Definitions Pleural plaques are discrete areas of hyaline or calcified pleural fibrosis, which have been localised on the parietal pleura of the chest wall, diaphragm and mediastinum. Diffuse pleural thickening is a condition of more extensive, active and progressive pleural fibrosis, which involves the visceral pleura. Calcification may also occur in longstanding DPT. Diffuse Pleural Thickening Definition This pleural thickening appears more closely related to amphibole than chrysotile exposure (Hussain et al, 1999). In asbestos cement workers, diffuse pleural workers, diffuse pleural thickening is more common in those with more heavily exposed and also increases in incidence with increasing time since first exposure (Ribotta et al, 1998). There is also no consistent relationship between smoking status and diffuse pleural thickening. Clinically assessing asbestosis related illnesses The criteria used for diagnosing patients with asbestosis usually depend upon the purpose for which a diagnosis is required. Clinically, diagnosis depends on establishing the presence, extent and nature of pulmonary fibrosis and whether there has been a exposure of a duration and intensity sufficient to put the individual at risk for developing asbestosis (Jones, 1991). Clinically, the fewer the features, the less certain the diagnosis and the more trivial the exposure and therefore the less likely that it is causal. When radiological or lung function changes are marginal, CT or HRCT often tend to reveal the presence of parenchymal abnormalities usually associated with pleural thickening or plaques (discussed later in this section). A biopsy of the lung can also be performed if there is absence of adequate exposure history. The biopsy is usually conducted to establish the nature of the disease and establish the presence and burden of asbestos in the lungs. 110 The diagnosis of asbestosis for the purpose of legal reasons requires reliable certainty and the use of criteria that vary accordingly to the legal administrative system involved (Rom, 1998; Harber et al, 1995; Parkes, 1994; Churg, 1998). Published papers usually consider histopathological criteria as the best means of establishing the diagnosis (Harber et al, 1995; Bégin et al, 1989). In the absence of histopathological criteria the following criteria are proposed: 1) a reliable history of asbestos exposure; 2) an appropriate lag time between exposure and detection; 3) there also needs to be evidence of lung fibrosis on the chest radiograph or HRCT scan; 4) a restrictive pattern of lung function; 5) bilateral fixed inspiratory crackles; and lastly 6) clubbing of the fingers or toes, or both. Of these history or exposure and evidence are considered essential and others are regarded as confirmatory (Bégin et al, 1989). Clinical Features Most patients diagnosed with asbestosis are asymptomatic for at least 20 to 30 years after the initial exposure. Asbestosis has been referred to as a monosymptomatic disease because of the most distressing symptom, dyspnoea (Selikoff, 1978). Dyspnoea first occurs after heavy effort and then as the disease progresses it occurs progressively on diminishing levels of exertion. Clinically, dyspnoea precedes other evidence of disease and therefore the clinician, because of its subjective nature, may underrate this. The relationship of dyspnoea to exposure levels in studies of exposed work forces has been a good reason to take it seriously in any exposed individual (Becklake et al, 1991). Another symptom, which usually manifests, is a persistent cough and sputum is also commonly reported (Ernst, 1991; Huuskonen et al, 1978). The cough is dry, occurs with distressing spasms and has been attributed to the stimulation of lung receptors. A productive cough is usually associated with smoking. Chest tightness or pain, or both, is not uncommon and may be caused by acute asbestos-associated pleural reactions. Another early distinctive feature of asbestosis is basal crackles which are usually fine crisp sounds, often heard first over axillary and basal regions and then generally as the disease advances (International Labour Office, 1997; Parkes, 1994). Other sounds include coarse crackles and rhonchi that usually reflect airway disease that maybe 111 related to cigarette smoking or to dust in the occupational environment (Becklake, 1989). Clubbing of the fingers and occasionally the toes develops in some subjects. Late manifestations include respiratory and circulatory failure and these, with cancer, are common causes of death (Huuskonen et al, 1978). Lung Function Asbestosis, which has been established, is usually associated with a restrictive lung function profile. FVC and the diffusing capacity in less advanced radiologic disease are usually reduced; reduction in flow at low lung volumes is a common finding in keeping with small airway abnormality (Wright et al, 1992; Bégin et al, 1989; Bégin et al, 1995; Ernst et al, 1991). Management, prevention and health monitoring Clinical management of asbestos-related lung conditions is different from management when there is no history of asbestos exposure. The clinician is bounded by law to make the appropriate notification of any case of asbestos-related diseases; another issue is that the clinician must face how to advise the patient of any future employments issues; guidance is usually based on the natural history of the disease processes with or without further exposure (Becklake, 1991; Ernst et al, 1991; Craighead et al, 1982). No active treatment measures have been shown to influence the course of asbestosis. Drugs advocated for interstitial lung diseases prove to be less effective as the active agent remains in situ in the lungs. Control and prevention of the disease is a public health issue as discussed earlier. This requires a successful control of the work force environment, setting and enforcing of standards and pre-employment or in-service health examination for exposed workers as part of a health-monitoring program. Quitting cigarette smoking benefits the asbestos-exposed individual (International Agency for Research in Cancer, 1996). Summary Asbestosis is a chronic restrictive lung disease that affects the parenchymal tissue of the lungs. It often occurs after minimal exposure to asbestos. Patients diagnosed with asbestosis usually suffer from dyspnoea. One of the primary symptoms of asbestosis 112 is the slow onset of shortness of breath upon exertion. Coughing is not a typical symptom. Most cases of asbestosis do not become apparent until five to ten years after the initial exposure to the material. Asbestosis is scarring of the lung tissue due to the inhalation of the asbestos fibres. Here are two types of fibres, amphibole and serpentine. There is no curative treatment; oxygen therapy is often necessary to relieve the shortness of breath along with physiotherapy and chest percussion. Nebulised medication may also be offered. Currently there is no research being conducted to investigate the psychological consequences of living with asbestosis and related illnesses and if sleep is disturbed in such a disease. 113 2.3 Studies investigating disturbed sleep and psychological well-being in individuals diagnosed with respiratory diseases This chapter provides a review of the literature which has focused upon disturbances in sleep and psychological well-being in individuals diagnosed with respiratory diseases. Appendix 1 describes the databases and keyword search terms used for the literature review. The review has been grouped into three sections. • Firstly, sleep studies of individuals with respiratory diseases using physiological and questionnaire methodology. • Secondly, studies which have focused on the psychological aspects of being diagnosed with respiratory diseases; these studies have used the questionnaire method to collect data on psychological functioning and how this affects an individual’s well-being. • Thirdly, studies, which have looked at psychological functioning in individuals diagnosed with obstructive sleep apnoea syndrome. These studies have been presented as they have focused on the variables that are being researched in the present study; these being excessive daytime sleepiness, mental health, general health, mood and memory, these studies also use similar methods to the present study and, finally, a conclusion. Sleep disorders are common in the general population but certain populations such as older adults, women and individuals with medical conditions (for example, respiratory diseases) are at greater risk (Zee and Avidan, 2006). This is an area of research which has been neglected. 2.3.1 Sleep studies of individuals with respiratory diseases The studies reviewed in this section are concerned with sleep in individuals diagnosed with respiratory diseases. These studies have investigated disturbed sleep using physiological studies and the questionnaire method to investigate disrupted 114 sleep. Asthma and COPD are the most extensively studied respiratory diseases in terms of investigating disturbed sleep but the investigation has still been very limited (Douglas, 1994). Each disease will be discussed in turn in relation to sleep. Sleep in individuals diagnosed with asthma using objective methods The number of individual studies with asthma in relation to asthma and sleep are rather limited, despite the potential importance of such work (Avidan and Zee, 2004). It is not clear from the sleep literature whether the incidence of asthmatic attacks is greater or lesser in sleep than during waking hours. Pulmonary disease specialists state that the incidence of asthmatic attacks is more frequent during the evening hours and during sleep than during daytime (Avidan and Zee, 2004). Only a few studies have actually attempted to determine whether asthma is more likely to occur at one time of the night than another and whether it occurs more often in one stage of sleep or another (Avidan and Zee, 2004), due to the fact that only small numbers are involved it is quite difficult to draw a conclusion. However having said this, the following studies highlight the sleep disturbance in individuals diagnosed with asthma. A study by Ravenscroft and Hartmann (1968) studied three individuals diagnosed with asthma on twenty one subject nights. During this there were thirty seven asthmatic attacks. The investigators found that twenty attacks occurred during Stage 1 REM sleep. When the asthmatic attack occurred during NREM sleep the individuals still reported dreaming in 62% of the instances. The investigators concluded that there is a strong temporal correlation of nocturnal asthma with sleep stage REM. In NREM, attacks are associated with reports of dreaming, and occur in Stage 1 or 2. No attacks occurred during Stages 3 and 4. The conclusions of this study are, however, based on just three individuals diagnosed with chronic asthma. A further study by Kales, Beall, Bajor, Jacobson, and Kales (1968) monitored twelve individuals with asthma with continuous all-night recordings of EEG, EOG, EMG and respiration for a total of thirty five nights. During the sleep study period, ninety three asthmatic episodes were noted, from these, seventy three occurred during REM sleep, eighteen in REM sleep, and two after lengthy awake periods. The attacks were 115 scattered throughout the night except for a lower incidence in the first hour of sleep. The investigators observed no obvious relationship between the asthmatic attacks and sleep stages, time of night, or both. Individuals with asthma did have disordered sleep and they also obtained less total sleep time than normal controls because of frequent awakenings and earlier final awakenings. They also had significantly less Stage 4 sleep, but REM percent was comparable to the normal controls. It can be said from this that asthma does disturb sleep and that the attacks are not related to any particular sleep stage or time of night in adults. Sleep in individuals diagnosed with asthma using questionnaire studies This section will present studies concerned with sleep quality and sleep disturbances in those individuals diagnosed with asthma. These studies have employed questionnaires as the method to collect their data. Asthma causes a variety of respiratory symptoms, which can impair the quality of life and lead to sleep disturbance, and this could persist even in individuals with hitherto well-controlled asthma by clinical parameters. This is an area that requires greater study. Studies of nocturnal asthma (Caterall, Calverley and Brezinova, 1982; Kales, Kales and Sly, 1968; Kales, Kales and Sly, 1970; Montplaisir, Walsh, Malo, 1982) have provided some data on sleep in patients diagnosed with asthma but these studies have been conducted in sleep laboratories which can affect the pattern of sleep due to the sophisticated instruments that are used to monitor sleep patterns. Recent attempts by Janson, Gislason and Boman (1990) and Fitzpatrick, Engleman and Whyte (1991) are the only studies that have attempted to highlight the problem of self-reported sleep disturbances in patients diagnosed with asthma and the effects that this can have on daytime functioning. Janson et al (1990) showed that the most common sleep disturbances amongst asthmatic patients were early morning awakening, difficulty in maintaining sleep (DMS) and excessive daytime sleepiness coupled with decreasing asthma control and increased number of acute asthmatic attacks. Patients also experienced an increase in DMS, nocturnal wakefulness nocturnal breathing problems and bronchodilator inhalations at night. 116 Fitzpatrick’s et al (1991) highlighted the problem of sleep quality and cognitive functioning in patients diagnosed with nocturnal asthma. Patients with asthma had poorer average scores for subjective sleep quality, objective overnight sleep quality. Daytime cognitive functioning was worse in patients with nocturnal asthma and generally took longer completing cognitive tests, achieved a lower score on the tests compared to their healthy counterparts. Sharpley (1996) has stated that the impact of daytime sleepiness in individuals with asthma can have potentially serious effects. Sleep disturbances in patients with asthma are likely to be under-reported (Van Keimpema, Ariansz, Nauta and Postmus, 1995) but the problems that patients face with sleep also include factors that are applicable to the non-asthmatic general population. These include insufficient or ineffective sleep, circadian rhythm disturbances and inadequate sleep hygiene. Nevertheless the few studies that have been conducted in this area have highlighted that asthma per se can disrupt sleep, these factors being troublesome day-time and nocturnal symptoms, lack of disease control and contributing psychological reactions of a chronic condition, such as anxiety, irritability and depression which can further trigger disrupted sleep and reduced Quality of Life. It has been estimated that more than 70% of people with asthma are troubled by sleep disturbances, which leaves them tired and unwell the following day (NAC, 2002). In a sleep study conducted in 2003 a significant deficit was found in the sleep ‘efficiency’ experienced by people with asthma compared to those without asthma (Hindmarch, 2003). Those with asthma enjoyed far less of the deep and restful sleep stages 3 and 4 than those without asthma and spent far more time awake. Many patients are unaware of the consequences that the lack of sleep brings, a survey of patients in one particular practice admitted to disturbed sleep because of their asthma, despite insisting their asthma was well controlled (Crockett, 1998). Sir John Floyer, who was an asthmatic patient himself, was the first person to give a clear description of nocturnal asthma in 1698 (Floyer, 1698). The mechanisms of this particular asthma are still not understood clinically (Douglas, 1985). Previous studies on nocturnal asthma in sleep laboratories have reported poor quality and shorter duration of sleep in asthmatic patients (Caterall et al, 1982; Montplaisir et al, 1982). 117 A significant feature, which has not received the attention it deserves, is the effect of asthma on the quality of sleep itself. Some efforts have been made to highlight the nature of sleep disturbances in asthmatic patients and its effect on daytime performances (Janson et al, 1990; Fitzpatrick et al, 1991) and Vir et al (in press). Current opinion indicates that the impact of daytime sleepiness, which has serious effects, has been underrated (Sharpley, 1996). Epidemiological studies have shown altered patterns in sleep in patients with obstructive lung diseases (Klink and Quan, 1987). This problem was highlighted by Turner-Warwick (1988) in a study where 7729 asthmatic patients being treated by their GP’s were observed: 74% reported they woke at least once a week due to symptoms relating to asthma; 64% woke at least three nights a week and 39% reported doing so every night. In a study by Janson, Gislason, Boman, Hetta and Roos (1990) sleep complaints and sleep disturbances was studied prospectively in ninety eight individuals diagnosed with asthma attending an out-patient clinic, by means of questionnaires and sleep diaries. The results from the individuals were compared to healthy age and sex matched group individuals. In individuals diagnosed with asthma early morning awakening, difficulty in maintaining sleep and daytime sleepiness was most commonly reported. As the individuals’ control of asthma decreased the disturbance in sleep increased, this being difficulty in maintaining sleep, nocturnal wakefulness, nocturnal breathing problems and bronchodilator inhalations at night. Shah et al (1997) reported that the commonest sleep disturbance observed in their research was maintaining sleep (60%) and early morning awakening (47%). No gender variation was reported in sleep disturbances but difficulty in maintaining sleep had a significant association with daytime naps in asthmatics. In one study individuals diagnosed with asthma reported more sleep disturbances and daytime somnolence than healthy controls, although individuals reported decreased sleep quality, decreased daytime mental fitness and an increase in daytime somnolence, there was no relationship between lung function and bronchial hyperactivity or nocturnal asthma (Van Keimpema, Ariaansz, Nauta and Postmus, 1995). 118 A random population study of young adults in three European countries aimed to investigate whether asthma is associated with decreased quality of sleep and increased daytime sleepiness. Amongst the assessments was a questionnaire on sleep disturbances, participants also estimated their sleep times and made peak expiratory flow recordings during a period of one week. Analysis revealed that individuals diagnosed with asthma reported difficulties inducing sleep, early morning awakenings and daytime sleepiness compared to healthy participants (Janson, Backer, Gislason, Plaschke, Björnsson, Hetta, Kristbjarnarson, Vermeire and Boman, 1996). Excessive daytime sleepiness is one of the most prominent symptoms that have been associated with obstructive upper airway disorders during sleep (Guilleminault, 1985; Guilleminault, 1994). Consequently excessive daytime sleepiness brings about significant deterioration in daily performance of patients in psychosocial and cognitive functions (ATS, 1998), mood swings and emotional distress (Churchill and Dilsaver, 1990; Jovanovic, 1991; Totterdell et al, 1994; Hill et al, 1996), poor performance on the job and during leisure activities (Pilcher and Huffcutt, 1996; Smith-Coggins et al, 1994) and creating a lack of general physical (Theoell et al, 1995) and mental well-being (Kupfer, 1995). Sleep in individuals diagnosed with COPD using objective methods Sleep quality is often poor in individuals diagnosed with moderate to severe COPD (Quan and Zee, 2004). Interrupted sleep can have serious negative consequences for individuals diagnosed with respiratory diseases, resulting in hypoxemia (Insufficient oxygenation of arterial blood) and hypercapnia (increase in carbon dioxide in the blood); these, in turn, can disturb sleep (Mohsenin, 2005). Hypoxemia and hypercapnia are likely to contribute to the disturbed sleep of individuals diagnosed with COPD. The worsening of hypoxaemia during sleep in individuals with COPD has been documented since the early sixties (Trask and Cree, 1962) and has since been confirmed by polysomnographic studies (Koo, Sax and Snider, 1975; Leitch, Clancy, Leggett, Tweeddale, Dawson and Evans, 1976). In a sleep study by Fleethan, West, Mezon, Roth and Kryger (1982) twenty four individuals diagnosed with COPD were recruited to compare oxygen therapy with air breathing in an attempt to 119 gain insight into oxygen desaturation during sleep. Fleethan et al found that during REM sleep the lowest mean of oxygen saturation occurred; only two individuals had episodes of sleep apnoea. Less than 23% of the individual’s sleep time was occupied with oxygen saturation, more than 5% below awake values. Age matched individuals were shown to have better sleep quality, sleep time, fewer sleep stage changes and decreased arousal frequency. Those individuals diagnosed with COPD in the study exhibited increased arousal frequency during reduced arterial oxygen saturation when they were breathing room air. Since no relief from the high arousal frequency was obtained with supplemented oxygen, the investigators concluded that hypoxemia itself was not to blame but hypercapnia. To further support this view, a study by Ballard, Clover and Suh (1995) assessed the influence of sleep on respiratory function in five individuals with COPD. Sleep was monitored during sleep in a horizontal body plethysmograph (a horizontal plethysmograph designed to accommodate supine subjects). Neither lung volume nor lower airway resistance changed in association with sleep. The investigators noticed a change in upper airway resistance during sleep and were highest during REM sleep, during wakefulness, stages 2, 3-4, respectively. Tidal volume was reported to decrease during sleep, resulting in a sleep associated decrement in minute ventilation during wakefulness, stages 2, 3-4, and REM sleep. The studies mentioned in this section so far have highlighted the respiratory problems that occur during sleep in individuals diagnosed with COPD. The majority of the studies have used polysomnography to investigate the disturbance in sleep, a reliable and objective method for investigating nocturnal disturbances. Sleep in individuals diagnosed with COPD using questionnaire methods Sleep quality is often impaired in patients with COPD (Cormick et al, 1986; Fleetham et al, 1982; Brezinova et al, 1982). During desaturation sleep fragmentation and arousals frequently occur Sandek et al, 1999). Philip et al (1994) has shown that fragmented sleep and frequent arousals lead to daytime sleepiness both in healthy normal adults and in patients with sleep disordered breathing (SDB). Cormick (1986) and Orr et al (1990) have both revealed that the scarce data available 120 regarding daytime sleepiness in patients with COPD are contradictory. A study by Saaresanta et al (2005) has highlighted that patients with moderate to severe COPD without acute exacerbations do not complain about excessive daytime sleepiness (EDS) as much as patients with obstructive sleep apnoea syndrome (OSAS) do. Many patients with COPD have frequent and prolonged episodes of hypoxemia during sleep (Flick et al, 1977; Interiano et al, 1972). According to Wynne (1978) these episodes maybe nocturnal or may occur during daytime naps, Wynne et al, (1978). Those mechanisms which mediate hypoxemia usually include airway obstruction, central apnoea, hypoventilation and oxygen desaturation without apparent breathing abnormalities (Koo et al, 1975). Patients with COPD usually show a combination of these etiological mechanisms during a single night’s sleep. There are several studies which have shown that recurrent transient hypoxemia during sleep is frequent in patients with COPD (Douglas et al, 1981; Becker et al, 1999). As mentioned earlier, hypoxemia is clearly marked in patients with a blue and bloated clinical phenotype and frequently occurs during REM sleep. As mentioned in the previous paragraph, symptoms related to sleep disturbances are common in moderate to severe COPD, as noted in a study by Bellia et al, (2003), particularly in elderly patients in the form of morning tiredness and early awakenings. Both depression and arthritis were the most significant independent correlates for the majority of sleep scores in the elderly population with COPD. In severe cases, the sleep disturbance is usually related to nocturnal cough, wheezing, and shortness of breath due to worsening of pulmonary mechanics and gas exchange during sleep. In a large survey of patients with COPD, Klink et al, (1994) found that with one respiratory symptom (cough or wheezing) present, 39% reported insomnia and 12% excessive daytime sleepiness. With both symptoms present the prevalence of insomnia and excessive daytime sleepiness were 53% and 23%, respectively. Sleep studies in COPD conducted by Calverley et al, (1982) and Fleetham et al, (1982) have shown poor-quality sleep as judged by marked increase in sleep stage changes, frequent arousals and awakening, and decreased total sleep time (summed Stages 2, 3, 4, and REM) with increased number of arousals. However, in an adult community 121 setting and part of the Sleep Heart Health Study, Sanders et al (2003) found that patients with mild obstructive airway disease (FEV1/FVC 63.8 ± 6.6%, mean ± SD) did not perceive themselves to have excessive daytime sleepiness and had minimally altered sleep quality and sleep architecture. Sleep disturbances are very common in the elderly (Prinz et al, 1990). A progressive decrease in duration and deterioration in quality of sleep may be assumed as a hallmark of aging. According to Douglas (1998) and Martin (1993) patients with COPD and asthma undergo changes in respiration along with other body functions along with nocturnal sleep. As a knock on effect, nocturnal exacerbations are frequently recorded in such patients. Banerjee et al, (1998) and Dow (1999) have illustrated that under-diagnosis in the elderly occurs frequently and the association between chronic airflow and sleep complaints in the elderly therefore deserve special attention as the prevalence of this association may be underestimated. As well, factors such as the role of physical limitation, cognitive decline and depression in influencing this association have not yet been evaluated. Although COPD and asthma are two different diseases nevertheless there is a risk of misdiagnosis in the aged (Ulrik et al, 1999); this is due to the loss of reversibility which accompanies longstanding asthma, therefore assessing the impact of asthma and COPD on the type of and severity of sleep impairment may contribute towards differentiating these conditions in the elderly. Studies which have used both objective and questionnaire methods to assess sleep and psychological functioning in respiratory diseases Within the literature search only one study was found which used both a sleep study and a survey method to assess sleep quality and daytime sleepiness in individuals diagnosed with COPD. This rare study, conducted by Saaresranta, Irjala, Aittokallio and Polo (2005), set out to investigate individuals with COPD who have impaired sleep quality without excessive daytime sleepiness and analysed the aetiological factors. Fifteen females with moderate to severe COPD and 20 healthy age matched women were studied. Individuals with respiratory diseases completed a questionnaire (BNSQ), had a polysomnography and a blood test. Healthy controls filled in only the 122 questionnaire. The average score for individuals diagnosed with COPD versus controls in terms of sleepiness and insomnia derived from the BNSQ was low. Although a high proportion of the individuals diagnosed with COPD reported having never slept well (70%) and sleeping restlessly, only a minority reported feeling tired in the morning (33%). Healthy controls reported better sleep quality, less tiredness and sleepiness. With polysomnography the total sleep time was four hours and forty one minutes ± one hour and twenty minutes in individuals diagnosed with COPD, sleep was also observed to be fragmented, the proportion of Stage 1 sleep was high and REM latency was delayed. It is important to use methods other than objective ones as some patients with good PEF may still report a poor QoL and vice-versa. Although PEF and QoL are correlated, this is not usually a strong correlation, as QoL can be affected by many other factors than PEF. Asthma care is not simply about managing the patient’s condition and correcting their respiratory function, it is also about maximising the patient’s QoL (Feeney et al, 1991). Clinicians and investigators have assumed that if clinical indices improve, then the patient must be feeling better. This may not be the case; conversely, some patients may experience an improvement in daily functioning that is not captured by the conventional outcomes (Juniper et al, 1995). An important factor, which has been highlighted through research investigating QoL and living with asthma, is that although physical functioning can be improved by better physiological control, the emotional aspects of asthma are more readily changed by psychological factors. The management of asthma involves both a physiological and psychological component. QoL assessments help the health professional to detect any psychological upset as well as to measure its improvement following effective patient management. Such measures can reflect the intangible cost of asthma and can also be a predictor of compliance (Rutten et al, 1995). COPD is associated with intermittent worsening of symptoms and lung function impairment. Not only do the exacerbation of symptoms contribute towards mortality and morbidity but also they considerably affect the QoL experienced by patients (Murray et al, 1997; Celli et al, 2004). Worsening usually occurs due to bacterial pathogens that are present in the LRT. Studies by Sethi et al, (2000) and Patel et al, 123 (2002) have shown that exposure to certain allergens and pollutants may also worsen symptoms. Saint et al, (1995) showed that although antibiotics are usually the main course of treatment for such patients, nevertheless their efficacy is debatable. Some studies under controlled conditions have shown that they do work and some have shown that they do not. Kim et al in 2004 have shown that the uncontrolled use of antibiotics in COPD exacerbations is very expensive and may contribute to the serious problems of emerging resistance to valuable antibiotics. Most asthmatic patients are usually treated with theophylline along with inhalers; it is not however known to what extent theophylline contributes to sleep impairment. There are reports to suggest that theophylline does contribute to disturbed sleep in patients who are unaccustomed to this drug, (Janson, Gislason, Almqvist and Boman, 1987). Patients who have been diagnosed with nocturnal asthma tend to benefit from the drug symptomatically. In a study by Janson and colleagues (1991) asthmatic patients who received theophylline and had reported sleep problems were given an alternative form of the drug known as enprofylline (both drugs have the same properties, the difference being that enprofylline is not a CNS stimulant). It was found that the difference in the drugs did not improve the quality of sleep in those patients treated with theophylline, suggesting that there may be some other underlying biological factors affecting the patients sleep. A study conducted by Hellgren, Omenaas, Thórarinn, Gíslason, Jögi, Franklin, Lindberg, Janson Torén on behalf of the RHINE study group (2007) conducted questionnaire research on a random population sample from North Europe aged between thirty and fifty four years of age; it was analysed in relation to perennial non-infectious rhinitis (nasal symptoms such as nasal blockage and secretion in the absence of common cold). Seventeen percent of the total sample reported perennial non-infectious rhinitis and this was said to be associated with an increase in having difficulty in maintaining sleep, early morning awakening and daytime sleepiness. This study showed that perennial non-infectious rhinitis is an independent risk factor for sleep disturbances in asthma. 124 2.3.2 Psychological studies of respiratory diseases Psychological well-being The studies mentioned in this section focus on the psychological well-being of individuals diagnosed with respiratory diseases. According to Osler (1903) most clinicians of this era would have agreed that there is a neurotic element to having been diagnosed with asthma. In 1966, Houston, Joiner and Trounce confirmed this statement in a popular textbook stating that there is some form of psychological influence that controls every asthmatic’s anxieties, whether starting them or maintaining them. The need for scientific support for an established association between psychological factors and asthma had its roots firmly established in the first part of the twentieth century. However, post-1990, references to psychological or psychosocial aspects of living with any respiratory disease, including asthma, is minuscule (Harrison, 1998). There appears to be a steady increase amongst academics and clinicians alike in understanding that psychological factors are associated with asthma (Greaves, Eiser, Seamark and Halpin, 2002). It is important to state that most studies concerned with psychological well being in respiratory disease are focused upon individuals diagnosed with asthma and a few individuals diagnosed with COPD; other areas still remain under researched to date. Previous studies have usually focused on the aspects of asthma dealing with morbidity, mortality and compliance in relation to emotional states such as depression, panic, fear and denial (Adams, Smith and Ruffin, 2000; Adams, Pills and Jones, 1997; Yellowlees and Ruffin, 1989) and cognitive factors have also been linked to asthma outcomes (Janson-Bjerklie, Ferketich and Benner, 1993). Individuals diagnosed with asthma have frequently been associated with having underlying psychological distress, such as depression and anxiety (Wright, Rodriguez and Cohen, 1998). In a study cited in Thorax (1997) the psychological characteristics of individuals with asthma were studied. Although there is no specific personality profile of individuals diagnosed with asthma (Chetta, Gerra and Foresi, 1998; Michel, 1994) there is, however, evidence of an association between atopic illnesses and depression (Wamboldt, Hewitt and Schmitz, 2000). A study by Janson, 125 Björnsson, Hetta and Boman (1994) has found an association between respiratory and psychiatric symptoms in healthy participants without respiratory diseases. In a study by Vamos and Kolbe (1999) levels of psychological distress, social support factors and emotional adjustment were measured in a sample of individuals with severe asthma. A sample of eighty individuals was recruited from a hospitalbased asthma clinic designed for individuals with severe asthma. Self-reported questionnaires were used to measure anxiety, depression, social support, emotional adjustment to asthma. Vamos and Kolbe found that at least 25% of the sample population had possible caseness for anxiety while fewer than 11% had caseness for depression. 25% had inadequate social support in some way. It was concluded that individuals diagnosed with severe asthma have high levels of distress, particularly anxiety. Although asthma is known to be influenced by a variety of physical, psychological and social parameters, the relationship between such parameters is less well understood (Jones, Kinsman, Dirks and Dhalem, 1979; Spittle and Sears, 1984; Nocon and Booth, 1991). In a study by Miles, Garden, Tunnicliffe, Cayton and Ayres (1997) these variables were further explored using a case control study on twenty-nine well-characterized brittle and non-brittle asthmatics in the West Midlands Region to assess their level of psychological morbidity. The GHQ and the Living with Asthma questionnaire was used and participants’ responses to changes in asthma symptoms, using the Asthma Symptom Checklist and a taped interview. The study highlighted the association of brittle asthma with greater psychological morbidity and altered strategies for coping with deteriorating asthma symptoms. Further support is provided by Dales, Spitzer, Schechter and Suissa (1988) who examined the influence of psychological status on respiratory symptoms was explored. Six hundred healthy subjects were selected from a population of just fewer than four thousand. Healthy subjects were defined as being between fourteen and fifty five years of age, having never smoked, had no diagnoses of respiratory diseases, no heart, kidney, thyroid disease or anaemia and having a normal spirometry (defined as FEV1 and FVC>eighty percent of predicted). Subjects’ scores from the American Thoracic Society respiratory symptom questionnaire (ATS-Q) 126 and Ilfeld Psychiatric Symptom Index (PSI) scores were compared. Dales and colleagues found that associations were found between respiratory symptoms (cough, phlegm, wheeze and dyspnoea) and PSI subscales (anxiety, anger, depression and cognitive disturbance). Methodologically, it is difficult to study respiratory symptoms together with psychological status. For example, it is often difficult to ascertain whether those individuals with higher levels of anxiety are more aware of their cough symptoms and whether it is the anxiety which has led to the increased awareness of the cough or whether if it is the underlying disease which is present which has led to the increase in anxiety and the increased reporting in the respiratory symptoms (Dales et al, 1988). Further studies exploring the relationship between anxiety and depression in relation to respiratory symptoms and asthma have been investigated by Janson and colleagues (1994), who further explored the relationship between psychological status and respiratory health. Seven hundred and fifteen individuals aged between twenty-two and forty-four took part in the European Commission Respiratory Health Survey. The study collected various respiratory data alongside a structured interview and psychological status was assessed using the HADS questionnaire. Significant correlations were found between anxiety and depression and asthma-related symptoms. The authors came to the conclusion that there is an association between reported respiratory symptom and psychological status. This also results in the indication that it may be valuable to include psychological status indicators in respiratory symptom questionnaires. The impact of psychological distress on the health of the population with asthma is not well described (Adams, Wilson, Taylor, Daly, d’Espaignet, Grande and Ruffin, 2004). In a study by Ware, Kosinski and Keller (1994) of a small sample of individuals diagnosed with asthma in the Medical Outcomes Study, asthma was associated with significant negative effects on the Mental Health Component Summary of the SF-36. 127 Quality of Life These studies focus on quality of life in individuals diagnosed with asthma and COPD. The relationship between QoL in adults with asthma is believed to be important but has not been well studied (Archea, Yen, Chen, Eisner, Katz, Masharani, Yelin, Earnest and Blanc, 2006). Quality of life in asthma is increasingly recognised as a clinically important health measure, reflecting the effect of disease from the perspective of the patient (Juniper, 2003). According to Rutten-Van, Custers, Van Doorslaer (1995), measures used to study quality of life are increasingly important in evaluating outcomes in asthma care. Questionnaires used include generic measures such as the SF-36 and respiratory specific measures such as the St George Respiratory Questionnaire (SGRQ) (Jones, Quirk, Baveystock, 1991) and the Asthma Quality of Life Questionnaire (AQLQ) (Juniper, Guyatt, Ferrie, 1993). There is also little information available in relation to asthma and QoL in elderly patients. A Medline literature search conducted between 1986 and 1997 using keywords such as “asthma”, “aged” and “QoL” detected only thirty-seven articles; most of the studies, however, were only of questionnaire validation studies, including a small sample of the elderly population (Burr et al, 1979; Burrows et al, 1991). In a study by Adams and colleagues (2004) a study showing the prevalence of psychological distress in asthma in the general population and its associations with QoL showed that psychological distress was more frequent in those with asthma and a higher proportion with asthma were at higher risk for anxiety or depression. Mental health conditions were also more common as was frequency of those who sometimes or always felt a lack of control over their health. People with both asthma and psychological distress scored significantly lower on the SF-12 physical component score than those with asthma or distress alone. There was also no difference in scores amongst individuals with asthma on the mental component score who had psychological distress. Although asthma remains one of the most frequently reported chronic respiratory disorders, if managed effectively, patients can be helped. According to the British 128 Thoracic Society, the guidelines for managing asthma indicate that the primary aim is to restore optimal lung function and to abolish or minimise symptoms and this is while using minimum medication, this being an objective measures of lung function. It is well reported that psychological and respiratory symptoms are mutually related. Work by Dales, Spitzer and Schecter (1989) shows that healthy participants are more like to report respiratory symptoms, these being cough, phlegm, wheeze and dyspnoea; the participants diagnosed with having a psychological disorder, such as anxiety, depression, anger or cognitive disturbances are also often reported. A study by Janson, Bjornsson and Hetta (1994) demonstrated the association between respiratory symptoms and psychological status. Patients diagnosed with asthma were no more anxious or depressed than any other participants with respiratory symptoms. Work by Cooper, Ryland, and Davies (1997) observed as well that the same relationship exists between psychological status and morbidity in patients with severe asthma. Most studies of asthma are conducted in secondary care as part of a specific study protocol with tight inclusion and exclusion criteria. Those patients who attended a secondary care facility using the inclusion and exclusion criteria results in patients who are not typical of the general population (Rimington, Davies, Lowe and Pearson, 2001). Insufficient patient knowledge, being able to manage with exacerbations, poor adherence to treatment and socioeconomic factors all affect the patient who suffers from asthma (Neville, Gribbein and Harrison, 1991; Padget and Brodsky, 1992; Reed et al, 1985). Psychological factors have also been suggested: Janson-Bjerklie et al (1992) suggested that the degree of distress during an asthma attack, perceived danger from asthma and the all important appraisal of social support were significant predictors of emergency room (ER) visits. In a study where asthmatic patients were asked to describe one episode from the previous month, Janson-Bjerklie et al (1992) concluded that the frequency of ER visits was not only significantly correlated with perceived and actual severity, suggesting ER visits to be the behavioural manifestations of the patients appraisal of danger and threat, but it was also found 129 that patients reported delaying before seeking help, suggesting that ER visits occur as a last resort and often after a period of unsuccessful coping with a flare-up. Psychological, psychosocial and attitudinal factors have been studied as possible contributory factors to illness and death in a variety of diseases (Watson and Pennebaker, 1989; Barsky and Wyshak, 1990; Steptoe, 1991; Viinamaki et al, 1993) as well as asthma (Yellowlees et al, 1988). Hypothesised pathways include effects on lung function directly (Hyland, 1990), on symptom reporting (Watson and Pennebaker, 1989; Dirks and Schraa, 1983), on healthcare use (Rea et al, 1986) and compliance with treatment (Dirks and Kinsman, 1982). In addition to this it has been shown that socioeconomic and psychological factors act as risk factors for poor outcome (Rea et al, 1986; Strunk et al, 1985; Miller, 1987). Studies looking at anxiety, fear and panic have consistently attracted the greatest interest; it has been shown that panic and fear occur at higher rates in people with asthma compared to non-asthmatic individuals (Kinsman et al, 1973; Dirks et al, 1973). This is measured as a response to the experience of breathlessness in one study (Thompson and Thompson, 1985). In 1989 a study published by Dales and colleagues found a strong positive association between respiratory symptoms and psychological status. Several studies have put forward explanations, the first one being that breathlessness is a known somatic product of anxiety (Bass and Gardner, 1985). As mentioned earlier, those patients with known psychological symptoms may be more likely to report respiratory ones (Bass and Gardner, 1985). Other studies have also suggested that patients diagnosed with bronchial asthma may be more likely to suffer from anxiety disorders and depression (Lyketsos, Karabetsos, Jordanoglou, Liokis, Armaglanidid, and Lyketsos, 1984). Such studies looking at the relationship between psychological and social factors should be taken into account when plans for the management of asthma are being devised. In studies that have looked at near-fatal asthma attacks (Sibbald, 1989; Campbell et al, 1995) the use of the General Health Questionnaire (GHQ) is found. Both Sibbald and Campbell et al found a prevalence of psychiatric illness of 38% 130 and 43% respectively. The scores obtained correlated with days lost from work/school and the frequency of asthma attacks (Campbell, 1995) which suggest an association between asthma and morbidity. It has been proposed that perhaps psychiatric morbidity may decrease an individual’s ability to care for themselves. Nevertheless, in Sibbald’s study the GHQ scores were not found to be associated with self-care in acute asthma as judged by the response to a hypothetical attack of asthma (Sibbald, 1989). Self-reports that are dependent on the respondents’ perception of physical sensations may be influenced by psychological factors. Further support has been provided by a study that reported significant differences in GHQ and living with asthma; this reinforced the presence of psychological factors in those patients living with asthma (Miles et al, 1997). Self-reports, dependent upon the participant’s perception of their own physical sensations, are inevitably and often importantly influenced by psychological factors. It follows that psychological factors could reduce bias and the precision of results. For example, participants who are exposed to atmospheric pollution would be expected to be more anxious and worried about their health and/or angry about their working conditions than those who are not exposed (Ware, Ferris, Dockery, Spengler, Strom and Speizer, 1986; Cotton, Graham, Li KYR, Froh, Barnett and Dosman, 1983). Another factor which may affect respiratory symptom reporting could be differences in psychological status which may be associated with personality characteristics which determine the selection of type of work or area of residence (Dales, Spitzer, Schechter and Suissa, 1988). The symptoms of COPD most frequently interfere with various aspects of living such as work life, family role, socialization daily living activities (Hanson, 1982). Individuals diagnosed with COPD have also been reported to be severely depressed, withdrawn, anxious and fearful (Rowlett and Dudley, 1978; Sandhu, 1986). Impairment in QoL, specifically depression, anxiety, fatigue, social role-functioning and home management activities were reported to be particular problems compared to healthy individuals (McSweeny, Grant, Heaton, Adams and Timms, 1982). 131 From the literature presented it can be seen that COPD is a progressively debilitating disease with an insidious onset. The symptoms which manifest in this condition frequently interfere with various aspects of living, such as work life, family roles, socialisation and the activities of daily living (Hanson, 1982). Guyatt et al, in 1987 conducted an extensive study that identified dyspnoea and fatigue as major problem areas in a survey of 100 subjects who were asked how their lives were negatively affected by COPD. In a study by Rowlett and Dudley (1978) and Sandhu (1986) factors such as depression, withdrawal, anxiety and feelings of fearfulness were reported. In a study comparing 203 healthy individuals with those living with COPD showed that the latter had a greater impairment in QoL. Again, factors such as depression, anxiety, fatigue, social-role functioning and home management activities were particular problem areas. Although assessment of QoL appears to be a particularly strong theme amongst rehabilitation nursing, from the literature presented so far most studies and most clinicians tend to heavily rely upon the clinical aspects of the patient’s condition rather than qualitative aspects of how they are coping with the condition with which they have to live. QoL has a variety of alternative terms that have been used such as life satisfaction, well-being, adjustment and self-esteem. QoL can be objectively measured by observing components such as income, housing, physical functioning work, SES and support networks and by measuring the subjective components, such as attitudes, perceptions, aspirations and frustrations (Frank-Stromborg, 1988). There are several studies that have looked at the QoL of patients living with COPD (Anderson, 1995; Brown et al, 1981; Guyatt et al, 1987 and Traver, 1988) and coping (Barstow, 1974; Chalmers, 1984; Post and Collins, 1981; Rowlett and Dudley, 1978). But none have looked at other factors that too are important and prevalent in patients whom have been diagnosed with COPD. The symptoms that are associated with COPD, such as breathlessness, wheezing and coughing, can have considerable effects on the physical and emotional and social aspects of a patient’s life. 132 2.3.3 Psychological functioning in individuals diagnosed with obstructive sleep apnoea syndrome This section has been included as it is the only area within sleep medicine that has been thoroughly investigated. The studies within this area have focused upon objectively studying OSAS using polysomnography and using questionnaire methodology. These studies are included as they closely research many of the variables that have been studied in the current research, these being; excessive daytime sleepiness, general health, mood, memory and cognitive functioning using questionnaires. Psychologically, secondary depression along with anxiety, irritability, and despair are associated with OSAS. Individuals with OSAS who have an increase in body weight will also experience increased severity in their symptoms. In the USA and other western countries it has been well established that obesity is progressively increasing (Kuczmarski, Flegal, Campbell and Johnson, 1994; Bjorntorp, 1998). This finding is important as visceral obesity and body fatness is associated with adverse health effects such as hypertension, coronary heart disease, stroke, insulin resistance type 2 diabetes, osteoarthritis and psychological problems (Bjorntorp, 1998). Nevertheless, there is not much evidence available relating to the respiratory complications of obesity and reduced exercise capacity, hypoxaemia and hypoventilation during sleep. The most common respiratory disturbance is the development of upper airway obstruction during sleep, which results in OSAS. A study performed with individuals with severe obesity (mean body mass index (BMI) > 42.4) showed that more than 50% of individuals without reported sleep-related disorders had OSAS. Individuals who are clinically obese do report having daytime sleepiness and fatigue. They have also reported having a lower QoL (Resta, 2001). Excessive daytime sleepiness has as well been reported to cause social and family problems (Johns, 1998). Little is known about the sleep-patterns and the sleep-related symptoms of obese people who do not present with OSAS; however, a study by Vgontzas, Tsigos, Bixler, Stratakis, Sachman, Kales, Vela-Bueno and Chrousos (1998) found that obese people without OSAS often report daytime sleepiness and fatigue. A study by Resta, Caratozzola, Pannaccrulli, Stefano, Giliberti, Carpagnano 133 and De Perzola (2003) showed that individuals with severe obesity, even those who did not have OSAS, had sleep related disorders and EDS; the authors reported that these findings could be due to a lower QoL, a higher prevalence of medical complications and an increased risk of occupational injury and social and family problems. Other associated features commonly reported with OSAS are cardiac arrhythmias, mild hypertension, hypoxemia and blackouts. Another feature of OSAS is cognitive impairment (Findley, Barth, Powers, Wilhoit, Boyd and Suratt, 1986; Engleman and Douglas, 2005; Kales and Caldwell, 1985; Ulfberg, Carter and Talback, 1996; Grunstein et al, 1995; Colt, Haas and Rich, 1991; Martin, Deary and Douglas, 1996; Roers, Zorick, Wittig, Conway and Roth 1989; Jennum and Sjol, 1993). In a disease specific inventory, two thirds experienced memory disturbance and three quarters problems with concentration (Flemons and Reimer, 1998). In most studies data have suggested an impairment of the so-called ‘executive functions’, a concept initially introduced by Luria (1996) and Lezak (1982), who defined cognitive functions as planning, programming, regulation and verification of goal-directed behaviour. Cognitive complaints are also present and frequent in elderly persons but their clinical significance remains uncertain (Schofield et al, 1997). For the sake of this thesis, other co-morbidities were taken into consideration but studies, which have investigated subjective cognitive complaints and cognitive performance, have given inconclusive results. Some studies have demonstrated a weak association (Schofield et al, 1997; Jonker et al, 1996) whereas other studies have failed to show any associations (Jorm et al, 1997; Blazer et al, 1997; Taylor et al, 1992; O’Connor et al, 1990). Many of these studies, undermining their usefulness, were based on cross-sectional data or clinical samples (Schofield et al, 1997; Jonker et al, 1996). Summary A review of the literature dealing with sleep and psychological functioning (QoL, mood and memory) in individuals diagnosed with respiratory diseases has been presented. The first set of studies presented were those studies that used physiological sleep studies to investigate the sleep of individuals diagnosed with 134 respiratory diseases. Asthma and COPD are two of the most extensively researched respiratory diseases in terms of sleep. It has been shown from these studies that sleep in individuals diagnosed with COPD and asthma is disturbed. Polysomnographic studies in individuals diagnosed with COPD have revealed disturbed sleep during REM, wakefulness, Stages 2, 3-4. Disturbed sleep can result in hypoxemia and hypercapnia but this can also cause the disturbed sleep in individuals diagnosed with COPD. Further polysomnographic studies have revealed that individuals diagnosed with asthma usually have asthmatic attacks during Stage 1 REM sleep, those attacks that occur during NREM sleep are usually reported as dreams by individuals Asthma attacks can also occur during Stage 2. This leads onto studies which have used the questionnaire method to investigate the psychological functioning, QoL and sleep in individuals diagnosed with respiratory diseases. Again, asthma and COPD are the only two respiratory diseases that have been studied extensively in relation to psychological functioning and QoL. Employing this form of methodology, only sleep in individuals diagnosed with asthma has been reported. All the studies reported in this area have highlighted the relationship between anxiety and depression in relation to respiratory symptoms. QoL is reported low in individuals diagnosed with asthma and COPD and sleep quality is reported as being poor in individuals diagnosed with asthma. These areas are still very much under researched and although there are specific areas from a psychological perspective which have been investigated there isn’t, however, research being published linking all these factors and understanding how the patient’s disease and psychological and social well being can contribute towards the symptoms. Only a few studies reported to have used both polysomnography and questionnaires to investigate sleep disturbances in individuals diagnosed with COPD. These individuals compared to their healthy controls reported to have never slept well, slept restlessly and had poor quality sleep. 135 The final section dealt with the psychological functioning (QoL, mood and memory) of individuals diagnosed with OSAS. These studies have been presented because OSAS has been thoroughly investigated both subjectively and objectively. The studies within this area have focused upon the variables that have been researched within the present study using questionnaires. This area has been extensively researched by both academics and clinicians. There is convincing evidence presented to suggest that this group of individuals do have poor psychological functioning (QoL, mood and memory) and disturbed sleep. This hopefully highlights the need for conducting this project in helping to investigate the disturbed sleep and psychological functioning in those individuals diagnosed with not just asthma but COPD, bronchiectasis and asbestosis. The studies within this area have provided a framework for further concepts to be explored which have not previously been investigated together using a combination of valid psychometric assessments. The review has also highlighted the need for further research within specific respiratory diseases these being; asthma, COPD, bronchiectasis and asbestos and related conditions. This is further discussed in the next section, 2.4. 136 2.4 Need and requirements for further research in individuals living with respiratory diseases concerning their sleep and psychological functioning The following points and issues emerge from the review of the literature that has been presented in the first part of this thesis. 1. Individuals with respiratory diseases are not a homogeneous group and there are considerable individual differences that can be identified from the literature in the introductory chapters. There is very little evidence which describes sleep disturbances and psychological functioning in patients who have been diagnosed with respiratory diseases, specifically asthma, COPD, bronchiectasis and asbestosis. However these studies have shown that individuals diagnosed with asthma and COPD will have some form of psychological dysfunction, particularly in their QoL, mood and memory. The present research conducted has suggested that the individuals symptoms and the consequences they have on the individuals general health and well-being adds to the overall anxiety, stress and poor health. 2. The limited amount of research that has been conducted on sleep problems in chronic illnesses has been difficult to interpret for a variety of reasons. Firstly, some studies have used a variety of physiological measures to measure sleep disturbances but have not had clear aims and outcomes for why sleep was studied and how it has impacted the individual. Secondly, although disturbed sleep has been reported in a variety of chronic illnesses, it is difficult to draw any conclusions about chronic illness and sleep disturbances. Thirdly, researchers have exclusively paid most attention to excessive daytime sleepiness without reference to other forms of underlying sleep disorders that may be present. Fourthly, much of the research has been conducted with individuals who are generally of a retired age; sleep changes with age and this has not been considered in some of the research. Further research should also take into account the following points: 137 1. Studies should include groups that have been diagnosed with respiratory diseases exclusively rather than other cohorts who have other underlying comorbidities, which may interfere with the results. 2. Further research should make comparisons between healthy cohorts and those with respiratory diseases to indicate the relative size and nature of the sleep problem and to be able to assess the possibility of characteristic types of sleep disturbance which may require particular types of management. 3. To be able to assess sleep problems and to take into consideration the wide range of sleep behaviours and disorders and to be able to use appropriate methods to study them. 4. Assessments used to study psychological function should be shown to be psychometrically valid and reliable and relevant to the theoretical issues involved. 5. Findings should be representative of similar populations and should only include appropriate sample populations. The next section deals with the methodology and data analysis from the present study, describing a survey in which an attempt was made to meet these requirements. It is the first study of its type known to the author. 138 3 A cross sectional survey of sleep disturbance and general well-being in participants with respiratory diseases and matched healthy controls To aid the reader, a detailed structure of this section is outlined below: 3.1 Aims 3.2 Method 3.2.1 Design 3.2.2 Procedure 3.2.3 Participant recruitment 3.2.4 Assessments 3.2.5 Ethical Approval 3.2.6 Data analysis 3.3 Results 3.3.1 Demographic characteristics Demographic characteristics of respiratory and control Groups Ethnicity Occupational status Highest level of education achieved Current Illnesses or physical disorder that patients and participants have at present or have had in the past 3 months Illnesses or physical disorders that participants have ever had Sleep disturbances in other family members 3.3.2 Sleep disorders and behaviours Asthma and asthma controls Disorders of initiating and maintaining sleep Features associated with obstructive sleep apnoea Other disorders/behaviours occurring during sleep Sleep related disorders/behaviours occurring during the day Time required for sleep and sleep duration COPD and COPD controls Disorders of initiating and maintaining sleep Features associated with obstructive sleep apnoea Other disorders/behaviours occurring during sleep Sleep related disorders/behaviours occurring during the day Time required for sleep and sleep duration Bronchiectasis and bronchiectasis controls Disorders of initiating and maintaining sleep Features associated with obstructive sleep apnoea Other disorders/behaviours occurring during sleep Sleep related disorders/behaviours occurring during the day Time required for sleep and sleep duration Asbestosis related conditions and controls Disorders of initiating and maintaining sleep Features associated with obstructive sleep apnoea 139 Other disorders/behaviours occurring during sleep Sleep related disorders/behaviours occurring during the day Time required for sleep and sleep duration Summary of 3.3.2 3.3.3 Daytime sleepiness Asthma and asthma controls COPD and COPD controls Bronchiectasis and bronchiectasis controls Asbestosis related conditions and controls Summary of 3.3.3 3.3.4 Quality of Life (QoL) Asthma and asthma controls COPD and COPD controls Bronchiectasis and bronchiectasis controls Asbestosis related conditions and controls Summary of 3.3.4 3.3.5 General Health Questionnaire-12 (GHQ-12) Asthma and asthma controls COPD and COPD controls Bronchiectasis and bronchiectasis controls Asbestosis related conditions and controls Summary of 3.3.5 3.3.6 Beck Depression Inventory (BDI) Asthma and asthma controls COPD and COPD controls Bronchiectasis and bronchiectasis controls Asbestosis related conditions and controls Summary of 3.3.6 3.3.7 Cognitive assessments Item 1: Do you suffer from concentration problems, more than compared to those of your own age? Item 2: Do you suffer from memory problems, more than compared to those of your own age? Asthma and asthma controls COPD and COPD controls Bronchiectasis and bronchiectasis controls Asbestosis related conditions and controls Summary of 3.3.7 3.3.8 Associations between sleep disorders and behaviours, daytime Sleepiness, quality of life, mental health, BDI and cognitive functioning Summary of 3.3.8 3.4 Summary 140 3.1 Aims The aims of the phase I research were as follows: To describe the occurrence and nature of self reported sleep disorders and behaviours in individuals who have been diagnosed with specific respiratory diseases: asthma, chronic obstructive pulmonary disease (COPD), bronchiectasis and asbestosis & related conditions and healthy controls To compare the findings with healthy individuals matched for age and sex on these measures and measures of excessive daytime sleepiness, quality of life, mental health and cognitive functioning. To investigate associations between the sleep problems and self reported daytime sleepiness, quality of life, mental health and daytime cognitive functioning in the groups with respiratory disease. 141 3.2 Method 3.2.1 Design This study is a cross-sectional questionnaire survey of individuals with specific respiratory diseases and age and sex matched healthy controls. 3.2.2 Procedure Pilot study A pilot study to check the suitability and acceptability of the assessments (please see section on assessments 3.2.4) used in the questionnaire was conducted. Specialist respiratory clinics based at Queen Alexandra Portsmouth Hospital held throughout the week were attended. Initially a total of 60 individuals, 10 from each from each of the following respiratory groups Asthma, Chronic Obstructive Pulmonary Disease (COPD), Bronchiectasis, Asbestosis, Asbestos Pleural Plaques, Asbestos Pleural Thickening were recruited via a database containing information concerning patients who were attendees of the respiratory clinics held at Queen Alexandra Hospital. Individuals were posted a pack containing a patient invite letter (appendix 2), the patient information sheet (appendix 3), a consent form (appendix 2), the study questionnaire (appendix 4), along with a stamped addressed envelope for the individuals to return their completed questionnaire. Main study – Individuals diagnosed with respiratory diseases. As with the pilot study, individuals diagnosed with asthma, COPD, bronchiectasis, asbestosis were recruited from the outpatient Respiratory Service at Portsmouth Hospitals NHS Trust under the supervision of the respiratory specialist. Recruitment during clinics Recruitment took place during clinic times. Individuals were approached and asked whether they would like to take part in a study and briefed on what the study involved. Individuals who expressed an interest were provided with a information sheet, once the information sheet had been read by the individual and they still expressed an interest to take part they were then given an invite letter along with a 142 consent slip. Individuals had the opportunity to take the information sheet and the invite letter away with them to carefully consider taking part rather than feeling hurried. Once consent had been given, the individual was given the questionnaire to complete either whilst waiting for their appointment or alternatively complete the questionnaire in the comfort of their own homes and return the completed questionnaire in the stamped addressed envelope which was given to the individual. Individuals who were not approached during clinic times were then approached by postal means. A letter of invite, a consent slip, the questionnaire booklet along with the patient information sheet and a stamped addressed envelope was posted to the individuals. Matched controls An attempt was made to recruit matched controls through staff based at University of Portsmouth, Queen Alexandra Hospital NHS Trust and Portsmouth City Council. The same packs of information were sent to the control participants as described above, the only difference being that the Invite letter (Appendix 5) along with the participant information sheet (Appendix 6) was tailored to those who did not have a diagnosis of respiratory diseases. 143 3.2.3 Participant recruitment Individuals diagnosed with respiratory diseases. Individuals recruited through the respiratory clinics were professionally diagnosed by specialist consultants in respiratory medicine at Portsmouth Hospitals NHS Trust, Queen Alexandra Hospital, using the current guidelines in respiratory management to care for individuals diagnosed with asthma, COPD, bronchiectasis and asbestosis & related conditions. The diagnosis of asthma, COPD and bronchiectasis is made by clinicians using the National Institute for Health and Clinical Excellence (NICE) guidelines and lung function tests. For further information on diagnosing asthma, COPD, bronchiectasis conditions can be accessed from: http://www.nice.org.uk Table 3.1 shows the total number of individuals diagnosed with respiratory diseases and healthy matched controls recruited into the study with respiratory diseases. Table 3. 1. Total number of individuals diagnosed with respiratory diseases and healthy matched controls recruited. Diagnosis Individuals diagnosed Healthy Matched with respiratory diseases Controls* Asthma 46 46 Chronic Obstructive 18 18 Bronchiectasis 16 16 Asbestos related 11 11 Pulmonary Disease (COPD) conditions *Matched for age and sex. Individuals diagnosed with respiratory diseases were recruited through QA Hospital outpatient’s respiratory clinic. These individuals had already had their diagnosis confirmed by a respiratory specialist and were under the care of the specialist and 144 seen at specific clinics. All individuals diagnosed with respiratory diseases who attended the outpatient’s clinic were approached by the researcher and invited to participate in the study. The individuals medical files were accessed to ensure that they did not have any significant co-morbidity that would interfere with the results. Any individual who did take part and was found to have a significant co-morbidity, their questionnaire was not included for analysis. Individuals diagnosed with respiratory diseases and healthy controls were matched for age and sex. A healthy control was matched to only one individual in a particular category. Exclusion and inclusion criteria for selecting individuals Table 3.2 shows the various factors that were taken into consideration to exclude and include individuals with respiratory diseases into the study. Table 3. 2. Exclusion and inclusion criteria for selecting individuals Principal inclusion criteria Specific respiratory diseases: Exclusion criteria <18- to give informed consent Significant co-morbidities Asthma Bronchiectasis COPD Asbestos related conditions Current/ex-smokers >10 pack year smoking history Clinically significant cardiopulmonary clinically significant neurological, renal, endocrine, gastrointestinal, hepatic, haematological abnormalities uncontrolled with standard treatment. Alcohol and recreational drug abuse. Treatment with immunodilators Non-English speaking individuals were excluded on the grounds that translation may have affected the reliability and validity of the measurement tools. Individuals were also able to exclude themselves if they felt they were unable to complete the 145 questionnaires. This included individuals who could not understand the instructions or the questionnaire due to having a poor understanding of English. Individuals who attended the outpatients respiratory clinic at QA Hospital did so through a referral process by their GP in primary care. Usually this involves the individuals GP contacting a specialist clinician and requesting an appointment to be sent out to the individual to be seen by the specialist. Healthy controls Criteria for selecting control individuals The research team ensured that healthy control individuals did not have any diagnosed respiratory diseases and other contra-indications. This was done by administering two screening questions to exclude such cases (Please see appendix 4). Diseases and contra-indications such as clinically significant cardiopulmonary abnormalities, clinically significant neurological, renal, endocrine, gastrointestinal, hepatic, or haematological abnormalities uncontrolled with standard treatment, alcohol and recreational drug abuse, treatment with any other immunomodulators which might interfere with the outcome of the assessments. Response rates A total of 290 questionnaires were sent to individuals diagnosed with respiratory diseases. Of the 290 questionnaires, 203 fully completed questionnaires that fulfilled the inclusion/exclusion criteria were used. This is a 70 % response rate. A total of 105 questionnaires were sent to healthy controls, all 105 questionnaires were fully completed and returned and used for the study. This was a 100 % response rate from the health controls. The matching process involved selecting an individual diagnosed with a respiratory disease from each category (asthma, COPD, bronchiectasis and asbestos and related conditions) and matching them to an individual healthy person. Individuals were matched according to exact age and sex. 3.2.3 Assessments This section describes the questionnaires used in the present study measuring sleep disturbances, daytime sleepiness, QoL, mood and memory. 146 Sleep disorders Basic Nordic Sleep Questionnaire (BNSQ) (Partinen and Gislason, 1995) The BNSQ is based on a five-point (scale from 1; never or less than once per month to 5 Daily or almost daily) quantitative scale. It has 27 different items in 21 main questions. The questionnaire is designed to question the patients sleeping habits and disorders for the past three months. This is a self-administered questionnaire. The BNSQ has been used widely in a variety of studies performed in Nordic countries during the last several years, and it has proven to be a valid tool (Partinen and Gislason, 1995). The BNSQ assesses the following areas: 1. Dysomnias – which consist of disorders of initiating and maintaining sleep (insomnias), disorders of excessive daytime sleepiness (hypersomnias) and circadian rhythm sleep disorders. 2. Parasomnias – which are disorders and behaviours occurring during sleep or made worse by sleep. 3. Medical/Psychiatric sleep disorders – Psychiatric disorders that impede sleep and therefore affect the person’s ability to sleep. 4. Proposed sleep disorders – most newly described sleep disorders fall into this category until replicated data is available in the literature. Individuals with respiratory diseases and healthy controls were also given the opportunity to write down anything they thought was important to the quality of their sleep. The BNSQ has served as a basis in many epidemiological studies preformed in the Nordic and also in other countries. In Finland and Iceland the questions from the BNSQ have also been adopted to routine clinical patient questionnaires in hospitals. Daytime Sleepiness The Epworth Sleepiness Scale (ESS) (Johns, 1991). The ESS is an eight-item questionnaire that has been proposed as a simple method for measuring daytime sleepiness in adults. The ESS is designed to measure sleep 147 propensity in a simple yet standardized way. The ESS is based on questions referring to eight situations; some known to be very soporific, others less so. The scale covers the whole range of sleep propensities from the highest to the lowest. The questionnaire is self-administered. The questionnaire has a high level of internal consistency as measured by Cronbach’s alpha (0.88). Comparisons between the ESS responses of 87 students on two separate occasions, 5 months apart, enabled an estimate to be made of the test-retest reliability of the questionnaire (Johns, 1992). The ESS is a simple and reliable method for measuring persistent daytime sleepiness in adults (Hardinge, Pitson and Stradling, 1995). Quality of Life The 36-item Short-Form Health Survey (SF-36) (Ware and Sherbourne, 1992). The 36-item short-form (SF-36) was constructed to survey health status and QoL in the Medical Outcomes Study. The SF-36 is designed for use in clinical practice and research, health policy evaluations and general population surveys. The SF-36 includes one multi-item scale that assesses eight health concepts. These are: Physical functioning, Role limitations due to physical problems, Social functioning, Bodily pain, General mental health, Role limitations due to emotional problems, Vitality, General health perceptions. The SF-36 is designed to be self-administered. Mental Health The General Health Questionnaire (GHQ-12) (Goldberg, 1978). The general health questionnaire (GHQ-12) is designed to detect psychiatric disorders among respondents in community settings and non-psychiatric clinical settings, such as primary care or among general medical outpatients. It is aimed at detecting those forms of psychiatric disorder that may have relevance to a patient attending an outpatient clinic, therefore the focus of the general health questionnaire is of psychological components of ill-health. In construction of the GHQ-12, the items selected were to cover four main areas and these being depression, anxiety, social performance, somatic complaints and on occasion sleep disturbance over the last four weeks. The questionnaire comprises twelve questions, asking informants about their general level of happiness, experience of depressive and anxiety symptoms, and sleep 148 disturbance over the last four weeks. Interpretation of the answers is based on a four point response scale scored using a bimodal method. The GHQ12 is designed to be self-administered. The Beck Depression Inventory (The BDI) (Beck, Ward, Mendelson, Mock and Erbaugh, 1961). The items in this inventory were primarily clinically derived. The instrument was designed to measure the behavioural manifestations of depression. The inventory is composed of 21 categories of symptoms and attitudes. The symptom-attitude categories are as follows: 1. Mood, 2. Pessimism, 3. Sense of failure, 4. Lack of satisfaction, 5. Guilty feelings, 6. Sense of punishment, 7. Self-hate, 8. Self accusations, 9. Self punitive wishes, 10. Crying spells, 11. Irritability, 12. Social withdrawal, 13. Indecisiveness, 14. Body image, 15. Work inhibition, 16. Sleep disturbance, 17. Fatigability, 18. Loss of appetite, 19. Weight loss, 20. Somatic preoccupation, 21. Loss of libido. Each category describes a specific behavioural manifestation of depression and consists of a graded series of 4 to 5 self-evaluative statements. The statements are ranked to reflect the range of severity of the symptom from neutral to maximal severity. Numerical values from 0-3 are assigned to each statement to indicate the degree of severity. This is self-administered questionnaire. Studies of the internal consistency and stability of the instrument indicate a high degree of reliability, (Beck, Ward, Mendelson, Mock and Erbaugh, 1961). Comparisons between the scores on the inventory and the clinical judgements by the diagnosticians indicate a high degree of validity. Concentration and memory problems Cognitive items (Jennum and Sjol, 1994). Authors Jennum and Sjol (1994) originally conducted an epidemiological study of 1504 females and males aged between 30-60 years, which is known as the DanMONICA II Study (Dan-MONitoring trends in CArdiovasuclar diseases) to highlight the fact that patients with obstructive sleep apnoea syndrome often complain that they have concentration and memory disturbances. Jennum and Sjol found that concentration and memory problems were associated with a tendency to morning depression, insomnia and partly with unintended sleepiness. Concentration problem 149 showed a positive correlation to habitual snoring and sleep apnoea, but memory problems did not show such correlations. Classification of cognitive complaints: Concentration problems: This was assessed by using the following phrase: ‘Do you suffer from concentration problems? Memory problems: This was assessed by using the following phrase: ‘Do you suffer from memory problems, more than compared to those of your own age?’ The responses for both sets of items were: Not at all, slightly, moderately, quite a bit and very much. Demographic information Additional information was collected to complete the questionnaire booklet, this included demographic details (name, address, date of birth, height, weight, smoking history, occupation, qualifications, ethnicity, gender) and whether the participants had previous illnesses, previous medications had been taken, current medication taken and current diagnosed illnesses and if they know of anyone who suffers from a diagnosed sleep disorder (mother, father, siblings, husband, wife). 3.2.4 Ethical approval Ethical Approval was gained from the Local Research Ethics Committee for the Portsmouth and Isle of Wight Healthcare Authority (this can be found in appendix 7a). The Portsmouth NHS R and D Consortium also gave approval (this can be found in appendix 7b). 3.3.5 Data analysis The information collated from clinics was compiled into an Excel spreadsheet. The questionnaire data was coded and analysis was carried out using SPSS version 16. A range of statistical tests were used. Details of the analyses are given in the appropriate sections. 150 3.3 Results Introduction The results section is divided into 8 main sections: Demographic characteristics of respiratory and control groups, sleep disorders and behaviours, daytime sleepiness, QoL, and general health and well-being, mental health, depression and anxiety and cognitive functioning: memory and concentration problems. Participants (healthy and respiratory) were matched according to age and sex. 3.3.1 Demographic characteristics Demographic characteristics of respiratory and control Groups Table 3.3 shows a breakdown of the demographic characteristics; age, number of males and females, height and weight and body mass index (BMI). Table 3. 3. General characteristics of all groups. Group (N) Age (Years) Mean S.D. Minimum Maximum Gender Male (%) Females (%) Weight (KG’s) Mean Minimum Maximum Height (CM’s) Mean Minimum Maximum Body Mass Index* (BMI) Mean Asthma (n=46) Asthma Ctrl (n=46) COPD (n=18) COPD Ctrl (n=18) Bronc (n=16) Bronc ctrl (n=16) Asbestos related conditions (n=11) Asbestos ctrl (n=11) 53 15 22 79 53 15 22 76 66 10 52 77 66 10 52 78 56 14 35 78 56 14 34 78 67 9 53 76 67 9 53 79 18 (39) 18 (39) 7 (39) 7 (39) 5 (31) 5 (31) 9 (82) 9 (82) 28 (61) 28 (61) 11 (61) 11 (61) 11 (69) 11 (69) 2 (18) 2 (18) 77 39 140 74 44 108 73 45 106 71 46 99 72 48 121 73 59 102 84 67 95 78 64 95 168 147 188 169 152 188 167 155 183 170 152 193 166 150 182 168 157 180 176 165 183 174 157 188 27 26 26 25 26 26 27 26 *BMI Less than 20 — Under Weight, BMI 20-25 — Normal Weight BMI 25-30 — Over Weight, BMI 30-40 — Obese, BMI Over 40 — Severely Obese Individuals with respiratory diseases and healthy controls were broadly similar with respect to their height, weight and BMI. 151 Ethnicity The following shows the ethnic background of individuals with respiratory disease and their healthy controls. Table 3. 4. Breakdown of ethnic groups across individuals diagnosed with respiratory diseases and healthy controls Ethnicity Asthma (n=46) N (%) Asthma ctrl (n=46) N (%) COPD (n=18) N (%) COPD Ctrl (n=18) N (%) Bronchiectasis (n=16) N (%) Bronc ctrl (n=16) N (%) Asbestos related conditions (n=11) N (%) Asbestos ctrl (n=11) N (%) White British English Asian Indian 27 (59) 37 (82) 17 (95) 16 (89) 14 (87) 12 (75) 10(91) 9 (82) 5(11) 1(5) Asian other Other Missing 1(6) 19 (41) 3 (7) 2(13) 1 (6) 1 (6) 1(9) 1(9) 2 (12) 1 (6) 1(9) The majority of participants were British English; there were, however, a small minority of patients from different ethnic backgrounds representing different groups across the UK. Individuals diagnosed with asthma show a more diverse range of patients recruited into the study. The other category was collapsed due to small numbers, this category consists of Scottish, Welsh, Irish, Other White, Mixed White & Black Caribbean, Mixed White & Black Africans and Mixed White & Asians. 152 Occupational status This section displays information relating to the individuals diagnosed with respiratory diseases and healthy controls (social and economic status). This information was extracted from The National Statistics Socio-economic Classification User Manual (Office for National Statistics 2005 Edition (Appendix 8). For the study participants were asked to state their main occupation; these data were then coded into the categories below according to The National Statistics Socioeconomic Classification User Manual. Table 3.5 shows the breakdown of the different employment background that the individuals diagnosed with respiratory diseases and healthy controls stated in the questionnaire. Table 3. 5. Social and economic status across all groups. *Socioeconomic scale Asthma (n= 46) N (%) Asthma ctrl (n=46) N (%) COPD (n=18) N (%) COPD Ctrl (n=18) N (%) Unemployed 5(11) 5(11) 1(6) 6(33) Employees in large organisation 15(32) 20(44) Lower professional and higher technical occupations 5(11) 1(2) Routine occupations 5(11) 4(9) 13(72) Retired 9(20) 8(17) 4(22) Other 7 (15) 8 (17) Bronchiectasis (n=16) N (%) 3(17) Bronc ctrl (n=16) N (%) Asbestos related conditions (n=11) N (%) Asbestos ctrl (n=11) N (%) 3(19) 1(9) 2(18) 5(32) 7(44) 3(27) 2(12) 1(6) 1(9) 1(5) 4(25) 1(6) 4(36) 7(39) 4(25) 3(19) 4(36) 1 (6) 1 (6) 1 (6) 1 (9) 1(9) 5(46) There are no major differences in SES between the asthma, bronchiectasis and asbestosis respiratory groups and their healthy controls. Within the COPD group a greater number of healthy controls were unemployed compared to the individuals’ diagnosed COPD group. Another major difference is the number of COPD patients reporting to work in routine occupations. The other category has been collapsed to include intermediate occupations, employers in small organisations and lower supervisory occupations due to small numbers. 153 Highest level of education achieved Table 3.6 shows the highest level of education that the participants have reported. Table 3. 5. Breakdown of educational qualifications across the groups. Educational level Asthma (n=46) N (%) Asthma ctrl (n=46) N (%) COPD (n=18) N (%) COPD Ctrl (n=18) N (%) Bronchiectasis (n=16) N (%) N (%) Asbestos related conditions (n=11) N (%) Asbestos ctrl (n=11) N (%) 3(19) 5(46) 4(36) Bronc ctrl (n=16) No qualifications 10(22) 7(15) 9(50) 6(34) 2(13) O’Level/GCSE 5(11) 7(15) 4(21) 1(5) 2(13) A’ Level/GCE 8(17) 4(9) 2(11) 1(5) 1(6) 1(6) 1(9) Degree or equivalent 8(17) 9(20) 1(6) 5(28) 6(37) 3(18) 3(27) Postgraduate qualification 4(9) 12(26) 1(6) 1(5) 1(6) 4(25) Other qualifications 10(22) 5(11) 1(5) 4(25) 2(13) Missing data 1(2) 2(4) 1(6) 3(18) 1(9) 2(19) 2(18) 3(19) 4(36) Within the asthma group and their healthy controls there are no major differences except for the amount of participants within the asthma control group have reported to achieve more postgraduate qualifications compared to participants diagnosed with asthma. Within the COPD group again there are no major differences other than healthy controls reporting to have gained higher educational qualifications. There are no major differences reported within the bronchiectasis and asbestosis group. 154 Current Illnesses or physical disorder that patients and participants have at present or have had in the past 3 months Information for this section was extracted from the British National Formulary, BNF 53, March 2007. Participants were asked to state “Current illnesses or physical disorders that they may have at present or have had in the past 3 months” and “any illness or physical disorder that participants have ever had.” This data was then coded into the categories displayed below. A brief description of each category can be found in appendix 9. Not all categories have been displayed, only those that represented the illnesses/disorders that the patients and participants have stated in the study questionnaire. The following table shows the breakdown of the various disorders that the individuals diagnosed with respiratory diseases and matched controls have stated in the last 3 months. Table 3. 6. Current illnesses or physical disorder that individuals diagnosed with respiratory diseases and healthy controls have at present or have had in the last 3 months. *Category Name any illness or physical disorder you have at present or have had in the last 3 months Cardiovascular disorders Gastrointestinal system disorders Obstetrics, gynaecology and urinary tract disorders Musculoskeletal and joint diseases disorders Endocrine system disorders Other None stated Missing Asthma (n=46) N (%) 7(15) 2(4) Asthma ctrl (n=46) N (%) 1(2) 1(2) COPD Ctrl (n=18) N (%) Bronchiectasis (n=16) N (%) Bronc ctrl (n=16) N (%) 1(6) 2(11) 4(25) 1(6) 1(6) 1(6) 1(6) 1(9) 2(11) 1(6) 2(18) 1(9) 1(6) 1(6) 6(55) 2(18) 1(6) 2(13) 7 (44) 3 (18) 7(45) 2(18) 2 (18) 6(55) 2(5) 6(13) 3(7) 22 (47) 2(5) 4(9) 7(15) 3(6) 7 (15) 25(55) 5(26) 4(22) 1(6) 9 (50) 1 (6) 8(44) 1(6) Asbestos related conditions (n=11) N (%) Asbestos ctrl (n=11) N (%) COPD (n=18) N (%) 3(19) There are no major differences observed within the asthma, COPD, bronchiectasis and asbestosis group and their healthy controls. 155 The other category consisted of skin disorders, ear, nose, oropharynx disorders, central nervous system disorders, psychiatric disorders and lastly respiratory disorders. 156 Illnesses or physical disorders that participants have ever had. Table 3.8 shows the number of participants who have reported to have ever had any of the physical disorders as listed in the table below. Table 3.7. Any illness or physical disorder that participants have ever had. *Category Name any illness or physical disorder that you have ever had Skin disorders Asthma (n=46) N (%) Asthma ctrl (n=46) N (%) 3 (7) 1(2) Cardiovascula r disorders Musculoskelet al and joint diseases disorders Endocrine system disorders Childhood illnesses disorders Other None stated Missing 2(4) 5(11) 1(2) 1(2) 5(11) 17(37) 4 (8) COPD (n=18) N (%) 2(11) COPD Ctrl (n=18) N (%) 1(6) Bronchiect asis (n=16) N (%) Bronc ctrl (n=16) N (%) 1(6) 1(6) 1(6) 1(6) 1(6) 1(6) 2(11) 1(6) 3(19) 4(9) 3(16) (6) 8 (17) 25(55) 2 (12) 6 (32) 8(43) 16(35) 9(50) 8(50) Asbestos related conditions (n=11) N (%) Asbestos is ctrl (n=11) N (%) 1(9) 2(18) 1(9) 1(6) 5(46) 1(9) 2 (13) 7(44) 2 (18) 2(18) 2 (18) 6(55) 6(38) Generally no major differences can be observed between the asthma and COPD group and their healthy controls. Individuals diagnosed with bronchiectasis and asbestosis have reported to have had more childhood related disorders. The other category consists of collapsed categories due to small numbers, the disorders which are included in this category are; ear, nose, oropharynx disorders, gastro-intestinal system disorders, Obstetrics, gynaecology and urinary tract disorders, central nervous system disorders, psychiatric disorders and lastly respiratory disorders. 157 Sleep disturbances in other family members Individuals diagnosed with respiratory diseases and healthy controls were asked to report any sleep disturbances or disorders within their immediate family that they may be aware of. Table 3.9 show the different family members who have been observed with sleep disturbances or sleep disorders by the individuals diagnosed with respiratory diseases and healthy controls. Table 3.8. Sleep disturbances in other family members as reported by individuals diagnosed with respiratory diseases and healthy controls Does anybody in your family suffer from a sleep problem? Who and what is the problem? No Asthma (n=46) N (%) Asthma ctrl (n=46) N (%) COPD (n=18) N (%) COPD Ctrl (n=18) N (%) Bronchiectasis (n=16) N (%) Bronc ctrl (n=16) N (%) Asbestos related conditions (n=11) N (%) Asbestos ctrl (n=11) N (%) 12(26) 40(88) 1(6) 16(90) 6(38) 11(69) 9(82) 9(91) Mother 25(55) 1(2) 13(72) 1(5) 5(31) 1(6) Father 3(7) 2(4) 2(13) 1(6) Sibling 1(2) 2(4) Other 4 (8) 1 (2) 1 (6) 1(6) No response 1(2) 2(12) 2(13) 1(9) 1(5) 1 (9) 4(22) Missing 1(9) Major differences can be observed within the asthma, COPD and bronchiectasis group, healthy controls and those diagnosed with a respiratory disorder, specifically those who have reported their mother as having family problems. The other category has been collapsed due to small numbers to include wife, grandparents, husband and other. 158 3.3.2 Sleep disorders and behaviours For a detailed and quantitative comparison of the matched groups, a score of either 0, 1, 2, 3, 4 was awarded for each participant depending on whether they reported the sleep problem or behaviour, never or less than once per month; 0, less than once per week; 1, on 1-2 days per week; 2, on 3-5 days per week; 3, daily or almost daily; 4, A mean score for each sleep problem or behaviour was then calculated for each group. As the data were measured on a scale that had an underlying continuous distribution and therefore met the assumptions of the parametric paired samples t-test, this was used to test for statistical significance between groups for each sleep problem and behaviour. As a more conservative analysis 2-tailed tests were used to test the data and no previous research has been conducted to suggest a definite direction of difference. Each of the respiratory groups and their healthy counterparts are described in turn. 159 Asthma and asthma controls The following table shows the mean scores in individuals diagnosed with asthma and their healthy controls. Table 3. 9. Mean scores obtained in individuals diagnosed with asthma and healthy controls. Sleep problem/behaviour Asthma Control mean (n=46) t-test P (2 tailed) 1.72 3.20 2.00 2.33 1.124 2.89 1.62 1.35 1.702 1.591 2.275 4.151 .096 .119 .028* <.0001*** 2.05 1.54 .95 1.51 .90 .19 1.573 2.274 3.072 .123 .028* .004** .60 .68 .32 .44 0 .02 .78 .44 .04 .05 .29 .05 .00 .12 0 0 .52 .42 0 0 1.334 3.455 2.201 2.149 0 1.000 1.372 -.121 1.431 1.000 .189 .001** .033* .037* 0 .323 .177 .904 .160 .323 2.27 2.16 .70 1.43 1.59 1.18 1.40 .38 .73 1.22 3.379 2.591 1.231 2.356 1.318 .002** .013* .226 .023* .194 Asthma mean (n=46) Disorders of initiating and maintaining sleep Difficulties falling asleep Waking during the night Occurrence of waking during the night Early waking Features associated with sleep disordered breathing Snoring Quality of snoring Breathing pauses Other disorders/behaviours occurring during sleep Narcolepsy Cataplexy Sleep paralysis Sleep talking Sleep walking Bed wetting Nightmares Teeth grinding Night screaming Rocking at night Sleep related disorders/behaviours occurring during the day Excessive sleepiness after awakening Excessive sleepiness during the day Excessive sleepiness during work Excessive sleepiness during leisure Daytime naps *P<0.05 **p<0.01 ***p<0.001 (2-tailed) Significant differences were found across all of the categories of sleep disorders and behaviours. Within the category of disorders of initiating and maintaining sleep the individuals with asthma reported significantly more waking during the night and early waking than the healthy controls. Within the category of features associated with sleep disordered breathing, individuals with asthma reported significantly poorer quality of snoring and breathing pauses than the healthy controls. 160 Within the category of other disorders/behaviours occurring during the day, the individuals diagnosed with asthma reported significantly more episodes of cataplexy, sleep paralysis, and sleep talking than the healthy controls. Within the category of sleep related disorders/behaviours occurring during the day, the individuals diagnosed with asthma reported significantly more excessive sleepiness after awakening, excessive daytime sleepiness during the day and excessive sleepiness during leisure than the healthy controls. Duration of sleep, daytime naps and years of snoring The following table shows the mean time (hours/minutes) for time required for sleep and sleep duration by participants within the asthma group and healthy controls. Table 3. 10. Mean time required for sleep and sleep duration as reported by participants within the asthma group and healthy controls. Sleep problem/behaviour Asthma mean (n=46) Asthma Control mean (n=46) t-test P (2 tailed) 24.11 20.17 .789 .436 21.50 18.76 .776 .443 6 63.90 20.70 26 7 20.70 8.40 33 -2.103 3.884 3.960 -1.948 .041* .001** .003** .109 Time required for sleep and sleep duration How many minutes do you stay awake in bed before you fall asleep (during working days) How many minutes do you stay awake in bed before you fall asleep (during free time) Sleep duration (hours) Duration of naps (minutes) Years of snoring (years) Age of onset of snoring (age) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Within the category time required for sleep and sleep duration the individuals with asthma reported sleeping significantly less hours than the healthy controls. Individuals with asthma reported napping for significantly longer periods and reported that they had been snoring for a significantly longer duration of years compared to the healthy controls. 161 COPD and COPD controls The following table shows the mean scores in individuals diagnosed with COPD and their healthy controls. Table 3. 11. Mean scores obtained in individuals diagnosed with COPD and their healthy controls. Sleep problem/behaviour COPD mean (n=18) COPD Control mean (n=18) t-test P (2 Tailed) Disorders of initiating and maintaining sleep Difficulties falling asleep Waking during the night Occurrence of waking during the night Early waking 2.00 3.50 2.59 2.47 1.67 2.78 2.06 1.71 .537 2.247 1.376 1.641 .598 .038* .188 .120 .86 .64 .44 2.00 .93 .31 2.280 -.806 .460 .040* .435 .652 Narcolepsy Cataplexy Sleep paralysis Sleep talking Sleep walking Bed wetting Nightmares Teeth grinding Night screaming Rocking at night Sleep related disorders/behaviours occurring during the day .71 1.35 .25 .31 0 0 .75 1.07 0 0 .24 .35 0 .44 0 0 .69 .60 0 0 1.224 2.062 1.732 -6.20 0 0 .187 .767 0 0 .239 .056 .104 .544 0 0 .855 .456 0 0 Excessive sleepiness after awakening Excessive sleepiness during the day Excessive sleepiness during work Excessive sleepiness during leisure Daytime naps 1.94 3.06 .55 2.11 3.11 1.22 2.06 .82 1.28 1.72 1.146 2.637 -1.000 1.667 3.571 .268 .017* .341 .114 .002** Features associated with SDB Snoring Quality of snoring Breathing pauses Other disorders/behaviours occurring during sleep *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Significant differences were found in three categories of sleep disorders and behaviours. Within the category of disorders of initiating and maintaining sleep, the individuals diagnosed with COPD reported significantly more waking during the night compared to healthy controls. 162 Within the category of features associated with sleep disordered breathing, healthy controls reported significantly more episodes of snoring compared to individuals diagnosed with COPD. Within the category of sleep related disorders/behaviours occurring during the night, the individuals with COPD reported significantly more excessive sleepiness during the day and longer daytime naps compared to healthy controls. Duration of sleep, daytime naps and years of snoring The following table shows the mean time (hours/minutes) for time required for sleep and sleep duration by participants within the COPD group and healthy controls. Table 3. 12. Mean time required for sleep and sleep duration as reported by participants within the COPD group. Sleep problem/behaviour Time required for sleep and sleep duration How many minutes do you stay awake in bed before you fall asleep (during working days) How many minutes do you stay awake in bed before you fall asleep (during free time) Sleep duration (hours) Duration of naps (minutes) Years of snoring (years) Age of onset of snoring (age) COPD mean (n=18) COPD Control mean (n=18) t-test P (2 tailed) 76.08 21.67 4.082 .002** 38.79 24.29 1.001 .335 6 52.86 25.00 50.00 6.5 28.57 40.00 30.00 -.153 1.642 0 0 .881 .124 *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found in this category. The individuals with COPD reported staying awake significantly longer in bed before falling asleep than the healthy controls. 163 Bronchiectasis and bronchiectasis controls The following table shows the mean scores of individuals diagnosed with bronchiectasis and their healthy controls. Table 3.13. Mean scores obtained in individuals diagnosed with bronchiectasis and their healthy controls. Sleep problem/behaviour Bronc mean (n=16) Bronc Control Mean (n=16) t-test P (2 tailed) 1.06 2.81 1.50 1.38 .81 2.62 1.56 .88 .522 .284 -.148 1.035 .609 .780 .884 .317 Snoring Quality of snoring Breathing pauses Years of snoring Age of onset of snoring Other disorders/behaviours occurring during sleep 1.64 1.93 .15 16.25 33.00 1.14 .50 .00 15.75 32.00 .959 3.069 1.477 .110 .167 .355 .009** .165 .920 .883 Narcolepsy Cataplexy Sleep paralysis Sleep talking Sleep walking Bed wetting Nightmares Teeth grinding Night screaming Rocking at night Sleep related disorders/behaviours occurring during the day .25 .25 .06 .44 .06 0 .75 .06 0 0 .50 .25 0 .25 .06 0 .25 .56 0 0 -.808 0 1.000 .716 0 0 2.449 1.519 0 0 .432 1.000 .333 .485 1.000 0 .027* .150 0 0 1.88 2.00 .43 1.12 1.31 .88 1.00 .29 .62 1.12 2.449 2.284 .520 1.225 .387 .027* .037* .612 .240 .704 Disorders of initiating and maintaining sleep Difficulties falling asleep Waking during the night Occurrence of waking during the night Early waking Features associated with SDB Excessive sleepiness after awakening Excessive sleepiness during the day Excessive sleepiness during work Excessive sleepiness during leisure Daytime naps *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Significant differences were found in 3 of the categories of sleep disorders and behaviours. Within the category of features associated with sleep disordered breathing, the individuals with bronchiectasis reported significantly more poorer quality in their snoring compared to healthy controls. 164 Within the category of other disorders/behaviours occurring during sleep, the individuals with bronchiectasis reported experiencing significantly more episodes of nightmares than the healthy controls. Within the category of sleep related disorders/behaviours occurring during the day, the individuals with bronchiectasis reported significantly more excessive sleepiness after awakening and during the day than the healthy controls. Duration of sleep, daytime naps and years of snoring The following table shows the mean time (hours/minutes) for time required for sleep and sleep duration by participants within the bronchiectasis group and healthy controls. Table 3. 14. Mean time required for sleep and sleep duration as reported by participants within the bronchiectasis group and healthy controls group. Sleep problem/behaviour Bronc mean (n=16) Bronc Control mean (n=16) t-test P (2 tailed) 16.30 32.00 -.770 .461 22.75 15.33 .880 .398 6.5 35.83 16.25 33 7 22.67 15.75 32 1.750 1.164 .110 .167 .102 .297 .920 .883 Time required for sleep and sleep duration How many minutes do you stay awake in bed before you fall asleep (during working days) How many minutes do you stay awake in bed before you fall asleep (during free time) Sleep duration (hours) Duration of naps (age) Years of snoring (years) Age of onset of snoring (age) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Within the category of time required to sleep and sleep duration, no significant differences were found between the individuals with bronchiectasis and healthy controls. 165 Asbestos related conditions and controls The following table shows the mean scores in individuals diagnosed with asbestos and related conditions and their healthy controls. Table 3. 15. Mean scores obtained in individuals diagnosed with asbestosis and healthy controls Sleep problem/behaviour Asbestos related conditions mean (n=11) Asbestos Control mean (n=11) t-test P (2 tailed) 1.45 3.27 1.91 2.64 1.82 2.91 2.00 2.45 -.599 .614 .000 1.104 .563 .553 1.000 .295 1.57 1.71 .00 2.00 .71 .38 -.441 1.528 1.426 .675 .177 .197 Narcolepsy Cataplexy Sleep paralysis Sleep talking Sleep walking Bed wetting Nightmares Teeth grinding Night screaming Rocking at night Sleep related disorders/behaviours occurring during the day 1.00 .50 .36 .09 0 0 .45 0 0 0 .90 .10 0 .18 0 0 .73 .36 0 0 .133 1.000 1.000 -.430 0 0 -.582 1.000 0 0 .897 .343 .341 .676 0 0 .574 .341 0 0 Excessive sleepiness after awakening Excessive sleepiness during the day Excessive sleepiness during work Excessive sleepiness during leisure Daytime naps 1.55 2.27 .60 2.30 2.44 1.73 2.27 .00 1.50 2.22 -.209 .000 1.500 1.238 .300 .839 1.000 .208 .247 .772 Disorders of initiating and maintaining sleep Difficulties falling asleep Waking during the night Occurrence of waking during the night Early waking Features associated with SDB Snoring Quality of snoring Breathing pauses Other disorders/behaviours occurring during sleep *P<0.05 **p<0.01 ***p<0.001 (2 tailed) There were no significant differences observed across the four categories of sleep disorders and behaviours. 166 Duration of sleep, daytime naps and years of snoring The following table shows the mean time (hours/minutes) for time required for sleep and sleep duration by participants within the asbestos & related conditions group and healthy controls. Table 3.16. Mean time required for sleep and sleep duration as reported by participants within the asbestos & related conditions group and healthy controls Sleep problem/behaviour Asbestos & related conditions mean (n=11) Asbestos Control mean (n=11) t-test P (2 tailed) 13.33 40.33 1.335 .314 18.12 16.50 .207 .842 6.1 64 11 42 6 13 14 27 2.500 2.796 -.273 5.084 .047* .049* .830 .001** Time required for sleep and sleep duration How many minutes do you stay awake in bed before you fall asleep (during working days) How many minutes do you stay awake in bed before you fall asleep (during free time) Sleep duration (hours) Duration of naps (minutes) Years of snoring (years) Age of onset of snoring (age) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Significant differences were found in this category. The individuals with asbestos & related conditions reported sleeping significantly longer and having significantly longer naps compared to healthy controls. Healthy controls reported to snore at a significantly earlier age compared to individuals diagnosed with asbestosis. 167 Summary of 3.3.2 Sleep disorders and behaviours In nearly all the items, individuals with respiratory diseases scored higher than healthy controls. Asthma and asthma controls In this group significant differences were observed; • Individuals with asthma reported; significantly more waking during the night, awoke earlier, and had significantly poorer quality of snoring and significantly more episodes of breathing pauses, significantly more episodes of cataplexy, sleep paralysis and sleep talking. They also reported significantly more excessive sleepiness after awakening, during the day and during leisure compared to healthy controls. • Individuals with asthma also significantly reported sleeping less, had significantly longer naps and had been snoring significantly a great deal longer compared to healthy controls. COPD and COPD controls In this group significant differences were observed; • Individuals with COPD reported waking significantly more during the night, significantly more excessive sleepiness during the day and having significantly longer daytime naps compared to healthy controls and staying awake significantly longer in bed before falling asleep compared to healthy controls. • Healthy controls significantly reported snoring on more nights compared to individuals diagnosed with COPD. Bronchiectasis and bronchiectasis control In this group significant differences were observed; • Individuals with bronchiectasis significantly reported poorer quality of snoring, significantly more episodes of nightmares, significantly more excessive sleepiness after awakening and significantly more excessive sleepiness during the day. Asbestos related conditions and controls In this group significant differences were observed; 168 • Individuals with asbestosis significantly reported longer duration of sleep and significantly more naps. • Healthy controls significantly reported to be snoring at a younger age compared to individuals diagnosed with asbestosis. 169 3.3.3 Daytime sleepiness Tables 3.18 to 3.21 provide the mean Epworth Sleepiness Score for each respiratory group. Asthma and asthma controls Table 3.18. Mean Epworth Sleepiness Score in individuals diagnosed with asthma and healthy controls. Asthma Asthma control Mean (Std Dev) Mean (Std Dev) (n=46) (n=46) 8.37(5.24) 6.59(4.99) t P (2 tailed) 1.594 .118 *P<0.05 **p<0.01 ***p<0.001 (2 tailed) No significant difference was observed between the individuals diagnosed with asthma and healthy controls although the individuals with asthma scored higher. COPD and COPD controls Table 3.19. Mean Epworth Sleepiness Score in individuals diagnosed with COPD and healthy controls. COPD COPD control Mean (Std Dev) Mean (Std Dev) (n=18) (n=18) 8.25(4.13) 6.06(3.91) t P (2 tailed) 1.441 .169 *P<0.05 **p<0.01 ***p<0.001 (2 tailed) No significant differences were found between individuals diagnosed with COPD and healthy controls although individuals with COPD scored higher. 170 Bronchiectasis and bronchiectasis controls Table 3.20. Mean Epworth Sleepiness Score in individuals diagnosed with bronchiectasis and healthy controls. Bronchiectasis Bronchiectasis control t P (2 tailed) 2.585 .021* Mean (Std Dev) Mean (Std Dev) (n=16) (n=16) 8.88(5.60) 5.12(2.94) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between individuals diagnosed with bronchiectasis and healthy controls in the mean score of ESS. Individuals diagnosed with bronchiectasis scored significantly higher than healthy controls. Asbestos related conditions and controls Table 3.21. Mean Epworth Sleepiness Score in individual diagnosed with asbestos & related conditions and healthy controls. Asbestos related conditions Mean (Std Dev) Asbestos control t P (2 tailed) .886 .397 Mean (Std Dev) (n=11) (n=11) 8.82(5.75) 6.64(3,41) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) No significant difference was found between individuals diagnosed with asbestosis and healthy controls, although individuals diagnosed with asbestosis scored higher on the ESS compared to healthy controls. Summary of 3.3.3 Daytime sleepiness Generally in all groups, the groups with respiratory disease scored higher then their healthy counterparts. A significant difference was only found within the bronchiectasis group. 171 3.3.4 Quality of Life The following section describes scores for the Short-Form 36 (SF-36) for individuals diagnosed with respiratory diseases and healthy controls. The SF-36 assesses quality of life across nine health concepts. These are: physical functioning, role limitations due to physical problems, role limitations due to emotional problems, social functioning, general mental health, energy/vitality, bodily pain, general health perceptions and change in health. In addition; transformed physical (PCS) and transformed mental (MCS), can be calculated (details of the procedure can be found in appendix 12). These health concepts were considered separately. Tables 3.22 to 3.25 shows the mean scores for the SF-36 subscales and transformed physical and transformed mental health concepts across all groups. A lower score relates to lower QoL. 172 Asthma and asthma controls Table 3.22. Mean SF-36 scores in the group with asthma and healthy controls. Category Physical function Role physical Role emotional Social functioning Mental health Energy/Vitality Pain General health perception Change in health Transformed physical Transformed mental Asthma Mean/Std Dev (n=46) 62.33/28.63 Asthma ctrl Mean/Std Dev (n=46) 86.74/35.57 Paired t-test P (2 tailed) -3.330 .002** 53.12/41.28 70.00/39.07 52.02/28.63 85.62/31.46 85.83/30.08 90.40/17.37 -5.025 -2.383 -7.342 <.0001*** .022* <.0001*** 63.27/17.72 48.11/18.89 59.01/29.75 47.58/17.64 74.81/15.66 62.44/21.83 66.41/23.02 73.60/21.03 -4.255 -3.629 -1.395 -6.394 <.0001*** .001** .170 <.0001*** 41.84/26.38 48.59/11.68 55.97/19.84 51.63/7.44 -2.818 -1.531 .007** .135 26.60/7.53 51.35/10.68 -13.367 <.0001*** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Significant differences were found across most of the SF-36 scales. Individuals with asthma scored significantly less than the healthy controls on the following SF-36 subscales (indicating a lower perceived QoL) these were; Physical function, role physical, role emotional, social functioning, mental health, energy and vitality, general health perception and finally change in health. A significant difference was also reported between individuals diagnosed with asthma who scored significantly lower compared to healthy controls in transformed mental health. 173 COPD and COPD controls Table 3.23. Mean SF-36 scores in the group with COPD and healthy controls. Category Physical function Role physical Role emotional Social functioning Mental health Energy/Vitality Pain General health perception Change in health Transformed physical Transformed mental COPD Mean/Std Dev (n=18) 18.82/13.63 COPD ctrl Mean/Std Dev (n=18) 73.83/20.83 Paired t-test P (2 tailed) -8.898 <.0001*** 9.37/25.61 33.33/44.09 59.47/21.85 67.18/45.38 73.33/42.16 84.96/18.40 -3.529 -3.141 -3.251 .004** .008** .005** 53.55/17.14 50.55/20.92 45.09/26.48 38.46/16.82 71.05/16.40 56.47/20.52 59.87/22.91 64.52/23.99 -2.682 -1.107 -1.432 -3.968 .016* .285 .171 .001** 27.77/29.56 27.95/7.82 54.16/23.08 45.93/9.17 -3.124 -4.04 .006** .002** 43.59/9.29 50.37/10.62 -1.576 .146 *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Significant differences were found across most of the SF-36 scales. Individuals with COPD scored significantly less than the healthy controls on the following SF-36 subscales (indicating a lower QoL) these were; Physical function, role physical, role emotional, social functioning, mental health, general health perception, and change in health. Individual diagnosed with COPD also scored significantly lower than healthy controls on transformed physical health. 174 Bronchiectasis and bronchiectasis controls Table 3.24. Mean SF-36 scores in the group with bronchiectasis Category Bronchiectasis Mean/Std Dev (n=16) Physical function Role physical Role emotional Social functioning Mental health Energy/Vitality Pain General health perception Change in health Transformed physical Transformed mental Paired t-test P (2 tailed) 72.33/33.90 Bronchiectasis ctrl Mean/Std Dev (n=16) 131.87/23.37 -6.095 <.0001*** 59.37/45.52 50.00/35.35 56.25/28.24 86.66/35.18 83.33/34.42 115.27/12.08 -2.168 2.988 -7.020 .048* .009** <.0001*** 72.25/14.12 43.50/14.37 57.63/30.14 51.66/20.34 105.00/15.91 70.00/19.23 69.44/22.03 78.50/23.93 -6.988 -4.171 -1.407 -3.652 <.0001*** .001** .180 .003** 46.66/18.58 35.97/7.39 48.43/17.00 56.29/7.04 -.250 -9.226 .003** <.0001*** 43.29/8.07 59.38/7.56 4.853 .000*** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Significant differences were found across most of the SF-36 scales. Individuals with bronchiectasis scored significantly less than the healthy controls on the SF-36 subscales (indicating a lower perceived QoL), these were; Physical function, role physical, role emotional, social functioning, mental health, energy/vitality, general health perception and change in health. Individuals diagnosed with bronchiectasis also scored significantly lower in transformed physical and transformed mental component scores compared to healthy controls. 175 Asbestos related conditions and controls. Table 3.25. Mean SF-36 scores in the group with asbestos & related conditions and healthy controls. Category Physical function Role physical Role emotional Social functioning Mental health Energy/Vitality Pain General health perception Change in health Transformed physical Transformed mental Asbestos related conditions Mean/Std Dev (n=11) 38.13/24.04 Asbestos ctrl Mean/Std Dev (n=11) t P (2 tailed) 116.87/24.19 -6.251 <.0001*** 34.37/49.88 18.29/18.24 57.57/25.73 62.50/51.75 87.50/35.35 106.06/17.47 -1.116 6.012 -8.281 .301 .001** <.0001*** 69.09/14.76 39.27/13.24 43.33/19.20 35.90/13.92 95.90/16.25 55.45/18.36 66.66/21.59 66.50/26.12 -4.403 -3.619 -2.739 -3.396 .001** .005** .023* .008** 31.81/16.16 22.33/12.93 50.00/22.36 52.43/10.50 2.667 -3.359 .024* .020* 44.11/9.16 55.51/6.96 2.883 .034* *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Significant differences were found across most of the SF-36 scales. Individuals with asbestosis related conditions scored significantly less than the healthy controls on the following SF-36 scales (indicating a lower perceived QoL), these were; Physical function, role emotional, social functioning, mental health, energy/vitality, pain, general health perception and change in health. Individuals diagnosed with asbestosis & related conditions also scored significantly lower in transformed physical and transformed mental component scores compared to healthy controls. 176 Summary of 3.3.4 Quality of Life Significant differences were observed in all the groups. Asthma and asthma controls • Individuals diagnosed with asthma scored significantly lower scores across the following SF-36 scales; Physical function, role physical, role emotional, social functioning, mental health, energy and vitality, general health perception, change in health and finally transformed mental health compared to healthy controls indicating significantly lower QoL. COPD and COPD controls • Individuals diagnosed with COPD scored significantly lower scores across the following SF-36 scales; physical function, role physical, role emotional, social functioning, mental health, general health perception, change in health and finally transformed physical health compared to healthy controls indicating significantly lower QoL. Bronchiectasis and bronchiectasis controls • Individuals diagnosed with bronchiectasis scored significantly lower on the following SF-36 scales; Physical function, role physical, role emotional, social functioning, mental health, energy/vitality, general health perception, change in health, and finally transformed physical and transformed mental component scores compared to healthy controls indicating a significantly lower QoL. Asbestos related conditions and controls • Individuals diagnosed with asbestos related conditions scored significantly lower on the following SF-36 scales; physical function, role emotional, social functioning, mental health, energy/vitality, pain, general health perception, change in health and finally transformed physical and transformed mental component scores compared to healthy controls indicating a significantly lower QoL. 177 3.3.5 General Health Questionnaire-12 (GHQ-12) This section describes the findings of the GHQ-12 questionnaire. The Likert scale (0, 1, 2, 3) was used to score the responses of the questionnaire which gave an overall individual global score of 0 to 36. Caseness can be obtained from the overall individual global score. Further information can be obtained from: http://www.gl-assessment.co.uk Tables 3.26 to 3.29 show the mean scores, standard deviations, t-test analysis and p values (2 tailed) for individuals diagnosed with respiratory diseases and healthy controls Asthma compared to Asthma control Table 3.26. Mean GHQ-12 scores in the group with asthma and healthy controls Asthma Asthma control t P (2 tailed) Mean (Std Dev) Mean (Std Dev) (n=46) (n=46) 14.61(7.52) 10.02(3.89) 3.469 .001** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between the individuals with asthma and healthy controls. Individuals with asthma scored significantly higher on the GHQ-12. 83 % of individuals with asthma scored above the threshold score compared to 50 % of healthy controls. 178 COPD and COPD controls Table 3.27. Mean GHQ-12 scores in the group with COPD and healthy controls COPD COPD control t P (2 tailed) Mean (Std Dev) Mean (Std Dev) (n=18) (n=18) 17.78(6.44) 9.72(3.96) 4.070 .001** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between the individuals with COPD and healthy controls. Individuals scored significantly higher on the GHQ-12. 39 % of individuals with COPD scored above the threshold score compared to 17 % of healthy controls. Bronchiectasis and bronchiectasis controls Table 3.28. Mean GHQ-12 scores in the group with bronchiectasis and healthy controls Bronchiectasis Bronchiectasis t P (2 tailed) Mean (Std Dev) control (n=16) Mean (Std Dev) (n=16) 11.75(5.10) 9.25(4.28) 1.768 .097 *P<0.05 **p<0.01 ***p<0.001 (2 tailed) No significant difference was found within this group, individuals diagnosed with bronchiectasis did however score highly on the GHQ-12 compared to healthy controls. 25 % of individuals diagnosed with COPD scored above the threshold score compared to 20% of healthy controls. 179 Asbestos related conditions and controls Table 3.29. Mean GHQ-12 scores in the group with asbestos & related conditions t P (2 tailed) Asbestos related Asbestos control conditions Mean (Std Dev) Mean (Std Dev) (n=11) (n=11) 14.45(4.90) 9.27(4.31) 3.866 .397 *P<0.05 **p<0.01 ***p<0.001 (2 tailed) No significant difference was reported between this group. 25 % of individuals diagnosed with asbestosis & related conditions scored above the threshold score compared to 12% of healthy controls. 180 Summary of 3.3.5 General Health Questionnaire (GHQ-12) Asthma and asthma controls • Individuals diagnosed with asthma scored significantly higher on the GHQ12 compared to healthy controls. 83 % of individuals scored above the threshold score compared to 50 % of healthy controls. COPD and COPD controls • Individuals diagnosed with COPD scored significantly higher than healthy controls. 39 % of individuals diagnosed with COPD scored above the threshold score compared to 17 % of healthy controls. Bronchiectasis and bronchiectasis controls • No significant difference was reported between this group. Individuals diagnosed with bronchiectasis did however still score highly on the GHQ-12 compared to healthy controls. 25 % of individuals diagnosed with COPD scored above the threshold score compared to 20 % of healthy controls. Asbestos related conditions and controls • No significant difference was reported between this group. Individuals diagnosed with asbestosis related conditions did however still score highly on the GHQ-12 compared to healthy controls. 25 % of individuals diagnosed with asbestosis & related conditions scored above the threshold score compared to 12 % healthy controls. 181 3.3.6 Beck Depression Inventory (BDI) This section describes the findings on the Beck Depression Inventory (BDI) in each group. The BDI consists of 21 items and assesses the symptoms which may correspond to the criteria for diagnosing depressive disorders as listed in the American psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders-Fourth editions (DSM-IV; 1994). The case scores, which include the means and standard deviations of the BDI-II scores by sample and diagnostic groups, can be found in appendix 19. The items have been considered separately. Tables 3.30 to 3.33 shows the global score for the BDI-II across all groups. Asthma and asthma controls Table 3. 30. Global BDI-II scores in the group with asthma Asthma Asthma control Mean (Std Dev) Mean (Std Dev) (n=46) (n=46) 15.67(13.10) 5.76(7.41) t P (2 tailed) 4.776 <.0001*** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Individuals diagnosed with asthma scored significantly higher on the BDI compared to the healthy controls. 182 COPD and COPD controls Table 3.31. Global BDI-II scores in the group with COPD and healthy controls COPD COPD control Mean (Std Dev) Mean (Std Dev) (n=18) (n=18) 19.83(7.83) 7.00(7.82) t P (2 tailed) 4.081 <.0001*** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Individuals diagnosed with COPD scored significantly higher on the BDI compared to healthy controls. Bronchiectasis and bronchiectasis controls Table 3.32. Global BDI-II scores in the group with bronchiectasis and healthy controls Bronchiectasis Bronchiectasis control t P (2 tailed) 2.384 .015* Mean (Std Dev) Mean (Std Dev) (n=16) (n=16) 7.56(6.30) 3.63(3.93) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Individuals diagnosed with bronchiectasis scored significantly higher on the BDI compared to healthy controls. 183 Asbestos related condition and controls Table 3.33. Global BDI-II scores in the group with asbestos & related conditions and healthy controls Asbestos related conditions Asbestos control Mean (Std Dev) Mean (Std Dev) (n=11) (n=11) 12.18(6.36) 5.36(3.58) t P (2 tailed) 3.858 .003** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) Individuals diagnosed with asbestosis scored significantly higher on the BDI compared to healthy controls. Summary of 3.3.6 Beck Depression Inventory (BDI) Significant differences were found across all groups diagnosed with respiratory diseases compared to the healthy controls. 184 3.3.7 Cognitive assessments Cognitive function was assessed using two items to measure memory and concentration problems. These have been adapted from the study by Jennum and Sjol (1994). The comparison for assessing whether individuals diagnosed with respiratory diseases have memory and concentration problems has been derived from the DanMONICA (MONItoring trends in cardiovascular diseases) data to evaluate the relation between snoring, sleep apnoea and cognitive complaints in adults. Those diagnosed with sleep apnoea in the Dan-MONICA study, scored a mean of 3.53 (concentration item) and 1.51 (memory item). Tables 3.34 to 3.41 show the mean scores of individuals with respiratory disease and healthy controls in these items: Classification of cognitive complaints: Concentration problems: This was assessed by using the following phrase: ‘Do you suffer from concentration problems more than compared to those of your own age?’ Memory problems: This was assessed by using the following phrase: ‘Do you suffer from memory problems, more than compared to those of your own age?’ The 2 items were considered separately. 185 Concentration problems Item 1: Do you suffer from concentration problems, more than compared to those of your own age?’ Asthma and asthma controls Table 3. 34. Mean Item 1 scores in the group with asthma and healthy controls Asthma Asthma control Mean (Std Dev) Mean (Std Dev) (n=46) (n=46) 1.96(1.11) .54(.808) t P (2 tailed) 7.416 <.0001*** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between the two samples. The mean score for individuals with asthma was significantly higher than the healthy controls indicating more self-reported problems with concentration. COPD and COPD controls Table 3.35. Mean Item 1 scores in the group with COPD and healthy controls COPD COPD control Mean (Std Dev) Mean (Std Dev) (n=18) (n=18) 2.00(.966) .81(.655) t P (2 tailed) 3.884 .001** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between the two samples. Individuals diagnosed with COPD scored significantly higher on the concentration items compared to healthy controls indicating more self-reported problems with concentration. 186 Bronchiectasis and bronchiectasis controls Table 3.36. Mean Item 1 scores in the group with bronchiectasis Bronchiectasis Bronchiectasis control t P (2 tailed) 5.196 <.0001*** Mean (Std Dev) Mean (Std Dev) (n=16) (n=16) 1.19(.403) .44(.629) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between the two groups. Individuals diagnosed with bronchiectasis scored significantly higher on the concentration item compared to healthy controls indicating more self-reported problems with concentration. Asbestos related conditions and controls Table 3.37. Mean Item 1 scores in the group with asbestos & related conditions and healthy controls Asbestos related conditions Asbestos control t P (2 tailed) 3.105 .011* Mean (Std Dev) Mean (Std Dev) (n=11) (n=11) 1.55(.934) .73(.647) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A Significant difference was found between the two samples. Individuals with asbestosis related conditions scored significantly higher on the concentration item compared to healthy controls indicating more self-reported problems with concentration. 187 Memory problems Item 2: Do you suffer from memory problems, more than compared to those of your own age? Asthma and asthma controls Table 3. 38. Mean Item 2 scores in the group with asthma and healthy controls Asthma Asthma control Mean (Std Dev) Mean (Std Dev) (n=46) (n=46) 1.78(1.22) .59(.77) t P (2 tailed) 5.574 <.0001*** *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A Significant difference was found between the two groups. Individuals diagnosed with asthma were significantly more likely to report memory problems than their healthy controls. COPD and COPD controls Table 3.39. Mean Item 2 scores in the group with COPD and healthy controls COPD COPD control Mean (Std Dev) Mean (Std Dev) (n=18) (n=18) 1.94(1.12) .69(.87) t P (2 tailed) 2.887 .011* *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between the two groups. Individuals diagnosed with COPD were significantly more likely to report memory problems than their healthy controls. 188 Bronchiectasis and bronchiectasis controls Table 3.40. Mean Item 2 scores in the group with bronchiectasis and healthy controls Bronchiectasis Bronchiectasis control t P (2 tailed) 3.576 .003** Mean (Std Dev) Mean (Std Dev) (n=16) (n=16) 1.12(.342) .56(.814) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between the two groups. Individuals diagnosed with bronchiectasis were significantly more likely to report memory problems than their healthy controls. Asbestos related conditions and controls Table 3.41. Mean Item 2 scores in the group with asbestos & related conditions and healthy controls Asbestos related conditions Asbestos control t P (2 tailed) 1.550 .011* Mean (Std Dev) Mean (Std Dev) (n=11) (n=11) 1.64(1.02) 1.00(.894) *P<0.05 **p<0.01 ***p<0.001 (2 tailed) A significant difference was found between the two groups. Individuals diagnosed with asbestosis & related conditions were significantly more likely to report memory problems than their healthy controls. 189 Summary of 3.3.7 cognitive assessments Concentration problems The mean score for individuals diagnosed with respiratory diseases was significantly higher than the healthy controls indicating more self-reported problems with concentration. Memory problems The mean score for individuals diagnosed with respiratory diseases was significantly higher than the healthy controls , individuals diagnosed with respiratory diseases were significantly more likely to report memory problems than their healthy controls. 190 3.3.8 Associations between sleep disorders and behaviours, daytime sleepiness, quality of life, GHQ-12, BDI and cognitive functioning Associations between sleep disorders and behaviours, daytime sleepiness, quality of life, mental health, depression and cognitive functioning were investigated in each of the respiratory groups. In order to investigate these associations, additional sleep scores were computed for each individual with respiratory disease. These sleep scores were based on the intuitive groupings of disorders of initiating and maintaining sleep (difficulties falling asleep, waking during the night, occurrence of waking during the night, early waking), features associated with sleep disordered breathing (snoring, quality of snoring, breathing pauses), other sleep disorders and behaviours occurring during sleep (narcolepsy, cataplexy, sleep paralysis, sleep talking, sleep walking, bed wetting, nightmares, teeth grinding, night screaming and rocking at night), sleep related disorders and behaviours occurring during the day (excessive sleepiness after awakening, excessive sleepiness during the day, excessive sleepiness during work, excessive sleepiness during leisure and daytime naps). For each of the sleep scores, the individuals score for each item in that particular group was summed to produce a composite score. Pearson correlation coefficients were then calculated between each sleep score and the daytime sleepiness score (ESS), quality of life (SF-36), mental health (GHQ), depression (BDI) and cognitive functioning (summed 2 items). This was carried out separately for each of the respiratory groups. The results are shown in tables 3.42 to 3.45. 191 Asthma Table 3.42. Pearson Correlation Coefficients for the Disorders of Initiating and Maintaining Sleep (DIMS), Sleep Disordered Breathing (SDB), other disorders during sleep, and other disorders during the day, and Epworth Sleepiness score (ESS), General Health Questionnaire score (GHQ-12), physical component score (PCS) and mental component score (MCS), Beck depression Inventory (BDI) score and cognitive functioning global score (Cog). ESS GHQ-12 PCS MCS BDI COG Daytime sleepiness General health Physical component score Mental component score depression Cognitive functioning Asthma Asthma Asthma Asthma Asthma Asthma DIMS score -.047 .254 -.473** .008 .337* .085 SDB .252 .211 -.414** .128 .240 .121 Other disorders during sleep .395** .386** -.393* -.202 .459** .190 Other disorders during day .635** .491** -.524** .142 .472** .274 Score *p<0.05 **p<0.01 ***p<0.001 (p=2-tailed) Individuals diagnosed with asthma Significant associations were observed within this group. A significant negative correlation was found between the DIMS and PCS showing higher scores on DIMS subscale was associated with lower quality of life relating to perceived physical component score. A significant correlation was found between the DIMS score and BDI score, showing higher scores on DIMS subscale was associated with higher levels of depression relating to the BDI scores A significant negative correlation was found between the SDB score and the PCS showing higher scores on SDB subscale was associated with lower quality of life relating to perceived physical component score. 192 Significant correlations were found between the other disorders during sleep score and the ESS, GHQ-12 and BDI. Higher scores on other disorders during sleep subscale were associated with higher scores on the ESS, GHQ-12, and the BDI. A significant negative correlation was found between the other disorders during sleep score and PCS showing higher scores on the other disorders during sleep subscale was associated with lower quality of life relating to perceived physical component score. Significant correlations were found between other disorders during day and ESS, GHQ-12 and BDI scores showing higher scores on other disorders during day subscale was associated with higher scores on the ESS, GHQ-12 and BDI. A significant negative correlation was found between other disorders during the day and PCS, showing higher scores on other disorders during the day subscale was associated with lower quality of life relating to perceived physical component score. 193 COPD Table 3.43. Pearson Correlation Coefficients for the Disorders of Initiating and Maintaining Sleep (DIMS), Sleep Disordered Breathing (SDB), other disorders during sleep, and other disorders during the day, and Epworth Sleepiness score (ESS), General Health Questionnaire score (GHQ-12), physical component score (PCS) and mental component score (MCS), Beck depression Inventory (BDI) score and cognitive functioning global score (Cog). ESS GHQ PCS MCS BDI COG Daytime sleepiness General health Physical component score Mental component score Depression Cognitive functioning COPD COPD COPD COPD COPD COPD DIMS score -.415 .085 .518 -.132 .137 .805** SDB .319 .073 .245 -.433 .272 .047 Other disorders during sleep .288 .333 -.017 -.199 .416 .498* Other disorders during day .139 -.198 .529 -.159 -.062 .215 Score *p<0.05 **p<0.01 ***p<0.001 (p=2-tailed) Individuals diagnosed with COPD Significant associations were observed within this group. A significant correlation was found between the DIMS score and cognitive functioning score showing higher scores on DIMS subscale was associated with greater problems with cognitive functioning. A significant correlation was found between other disorders during sleep and cognitive functioning score showing higher scores on other disorders during sleep subscale was associated with greater problems with cognitive functioning. 194 Bronchiectasis Table 3.44. Pearson Correlation Coefficients for the Disorders of Initiating and Maintaining Sleep (DIMS), Sleep Disordered Breathing (SDB), other disorders during sleep, and other disorders during the day, and Epworth Sleepiness score (ESS), General Health Questionnaire score (GHQ-12), physical component score (PCS) and mental component score (MCS), Beck depression Inventory (BDI) score and cognitive functioning global score (Cog). ESS GHQ PCS MCS BDI COG Daytime sleepiness General health Physical component score Mental component score Depression Cognitive functioning Bronc Bronc Bronc Bronc Bronc Bronc DIMS score .064 .004 -.244 .140 .153 .400 SDB -.145 -.518* -.490 .393 -.551* .011 .319 .582* .064 -.688** .657** .560* .698** .466 -.043 -.441 .555* .310 Score Other disorders during sleep Other disorders during day *p<0.05 **p<0.01 ***p<0.001 (p=2-tailed) Individuals diagnosed with bronchiectasis Significant associations were observed within this group. Significant negative correlations were found between the SDB score and the GHQ12 score and BDI scores showing higher scores on SDB subscale was associated with lower scores on the GHQ-12 and lower scores on the BDI scores. Significant associations were found between the other disorders during sleep and GHQ-12, BDI and cognitive functioning scores showing higher scores on other disorders during sleep was associated with higher scores on GHQ-12, BDI and cognitive functioning score. 195 A significant negative correlation was found between other disorders during sleep and MCS showing higher scores on other disorders during sleep subscale was associated with lower quality of life relating to mental health component score Significant correlations were found between other disorders during sleep and ESS and BDI scores showing higher scores on other disorders during sleep subscale was associated with higher scores the ESS and BDI scores. 196 Asbestos related conditions Table 3.45. Pearson Correlation Coefficients for the Disorders of Initiating and Maintaining Sleep (DIMS), Sleep Disordered Breathing (SDB), other disorders during sleep, and other disorders during the day, and Epworth Sleepiness score (ESS), General Health Questionnaire score (GHQ-12), physical component score (PCS) and mental component score (MCS), Beck depression Inventory (BDI) score and cognitive functioning global score (Cog). ESS GHQ PCS MCS BDI COG Daytime sleepiness General health Physical component score Mental component score Depression Cognitive functioning Asbestos & related condition Asbestos & related condition Asbestos & related condition Asbestos & related condition DIMS score .124 -.173 .044 -.148 .068 .240 SDB -.091 -.069 .280 -.040 -.026 .234 .397 .448 .201 -.300 .427 .224 .549 -.305 -.618 .038 -.165 .230 Asbestos & related condition Asbestos & related condition Score Other disorders during sleep Other disorders during day *p<0.05 **p<0.01 ***p<0.001 (p=2-tailed) Individuals diagnosed with asbestosis related conditions There were no significant associations found between any of the sleep scores and the individual items on the various questionnaires. 197 Summary of 3.3.8 Associations between sleep disorders and behaviours, daytime sleepiness, quality of life, mental health, depression and cognitive functioning Associations between sleep disorders and daytime behaviour problems Asthma • Generally, significant associations were found between sleep disorders and measures of psychological functions. As sleep problems increased in DIMS, quality of life associated with physical component score was lowered, however, depression scores increased. As SDB scores increased, quality of life associated with physical component score was lowered. Other disorders during sleep and other disorders during day increased so did the problems associated with daytime sleepiness, general health, physical functioning and higher scores of depression. COPD • Generally significant associations were found between sleep disorders and problems related to cognitive functioning. As sleep problems associated with DIMS and other disorders during sleep increased individuals diagnosed with COPD reported increased problems associated with memory and concentration. Bronchiectasis • Significant association were found between sleep disorders and problems related to daytime behaviour problems. As sleep problems associated with SDB increased, general health deteriorated along with increased feelings of depression. As sleep problems associated with other disorders during sleep increased poorer scores in general health, depression and cognitive functioning was reported, mental health deteriorated too. Individuals also reported increased daytime sleepiness and feeling more depressed as sleep problems associated with other disorders during day increased. 198 Asbestos related conditions • No significant associations were observed within this group between sleep disorders and daytime behaviour problems. 199 3.4 Summary of survey Differences between groups - sleep disorders • Significant differences were reported between individuals diagnosed with respiratory diseases compared to healthy controls across the sleep disorders and behaviours. Daytime sleepiness • A significant difference was found within the bronchiectasis group compared to healthy controls. No other significant differences were observed between the asthma, COPD and asbestosis group compared to healthy controls. Quality of life • Significant differences were observed in all the groups. Individuals diagnosed with respiratory diseases scored significantly lower on the SF-36 scales compared to healthy controls including the two component scores. General Health Questionnaire-12 • Individuals diagnosed with asthma, COPD and bronchiectasis scored significantly higher on the GHQ-12 questionnaire compared to healthy controls. • A greater proportion of individuals with respiratory diseases scored above the threshold score compared to healthy controls. Beck Depression Inventory • Individuals diagnosed with respiratory diseases scored significantly higher on the BDI compared to healthy controls. Cognitive assessments • Individuals diagnosed with respiratory diseases reported greater concentration problems compared to healthy controls. Significant differences were also 200 observed between individuals diagnosed with respiratory diseases compared to healthy controls in terms of memory problems. Associations between sleep disorders and daytime behaviour problems • Significant associations were found sleep disorders and measures of psychological function problems in individuals diagnosed with asthma, COPD and bronchiectasis. 201 4 Discussion Overview The reason for undertaking the present series of surveys was that they were concerned with topics of clinical importance to the care of individuals who have been diagnosed with respiratory diseases, more specifically asthma, COPD, bronchiectasis and asbestosis. It is evident from the literature review that there has been little previous work conducted within this area. Previous studies that have tried to address the issues raised within this study have been informative and of great importance. The findings from these studies have indicated a need for further research on the many points that they raise. The present research programme has a number of individual features that distinguishes it from previous research, which has been conducted in individuals diagnosed with respiratory diseases. These are as follows: 1. Investigation of a population based sample of such adults rather than adults whom have been referred for investigation to specialised sleep centres. 2. Comparison with a matched control group from the general population to assess the relative frequency and nature of the sleep problems. 3. Examination of the comparative profiles of sleep problems in adults diagnosed with specific respiratory diseases. 4. Comprehensive assessment of self-reported sleep disorders and behaviours of these adults as reported through the use of validated questionnaire. 5. Investigations of associations between sleep disorders, daytime behaviour problems, excessive daytime sleepiness and psychological functioning in adults diagnosed with respiratory diseases. The main aims were, firstly, to describe the occurrence and nature of self reported sleep problems in individuals who have been diagnosed with specific respiratory diseases namely asthma, chronic obstructive pulmonary disease (COPD), asbestosis, and bronchiectasis; secondly, compare the findings with those matched for age and 202 sex and finally investigate associations between the sleep problems and self reported daytime sleepiness, quality of life, mental health and daytime cognitive functioning in the groups with respiratory disease. 4.1 Summary of findings The data extracted from the BNSQ questionnaire measuring sleep behaviours and disorders The data analysed from the BNSQ questionnaire revealed those individuals diagnosed with asthma reported significantly greater problems related to sleep. Individuals diagnosed with asthma in this group reported more episodes of waking during the night, waking earlier than normal, exacerbated snoring, greater number of breathing pauses, greater number of episodes of cataplexy, sleep paralysis and sleep talking. They also reported feeling excessively sleepy after awakening during the day and during free time. Individuals diagnosed with asthma reported sleeping less but also reported longer episodes of napping during the day and snoring for a lot longer compared to healthy controls. Although individuals diagnosed with COPD also reported significantly greater problems related to sleep, these individuals revealed that they woke during the night a great deal more often compared to healthy controls. They also snored a lot more, felt excessively sleepy during the day, had a greater number of daytime naps and reported staying awake longer in bed before falling asleep, compared to healthy controls. Individuals diagnosed with bronchiectasis reported significantly worse snoring, experienced a greater number of nightmare episodes, reported feeling excessively sleepy after arousing and during the day, compared to healthy controls. The data analysed for individuals diagnosed with asbestosis revealed that these individuals slept significantly longer, napped for longer and started to snore at a much later age compared to their healthy counterparts. 203 The Epworth Sleepiness Scale data measuring daytime sleepiness The data analysed for daytime sleepiness revealed a significant difference between individuals diagnosed with bronchiectasis and healthy controls. No significant differences were found between individuals diagnosed with asthma, COPD and asbestosis compared to their healthy counterparts. These results will be discussed in greater detail in the next section. SF-36 scale and the physical and mental component score measuring QoL. Individuals diagnosed with asthma revealed significantly reduced QoL. These individuals were perceived to have reduced physical functioning, reduced emotional well being, reduced social functioning, reduced social functioning, reduced mental health, less energy and vitality in relation to quality of life. They generally thought, as well, that they had reduced health and that their health would either remain the same or be further reduced in the near future. The transformed mental component score was also significantly lower compared to healthy controls. Individuals diagnosed with COPD revealed a similar picture. These individuals reported reduced quality of life relating to physical component score, were perceived to have poor health, perceived to feel more emotionally withdrawn, have reduced social functioning, poor mental health and reduced general health. These individuals reported remaining the same or worse in the near future. The transformed physical component score was also significantly lower compared to their healthy counterparts. Individuals diagnosed with bronchiectasis reported significantly reduced QoL compared to their healthy counterparts. These individuals scored lower on all but the pain scale on the SF-36. Both the component scores for mental and physical health were significantly lower compared to their healthy counterparts. Individuals diagnosed with asbestosis reported significantly lower on the QoL SF-36 scales compared to their healthy counterparts. These individuals scored significantly lower on all but the role physical scale of the SF-36. Both the transformed physical and mental component scores were significantly lower than their healthy counterparts. 204 The GHQ-12 questionnaire data measuring mental health Individuals diagnosed with asthma reported significantly higher on the GHQ-12 compared to healthy controls. 83 % of these individuals revealed a psychiatric disorder similar to that of individuals attending an out-patient clinic compared to 50 % healthy controls. The psychiatric disorder revealed using the GHQ-12 are depression, anxiety, social performance, somatic complaints and occasionally sleep disturbances over a 4-week period. Individuals diagnosed with COPD scored significantly higher than healthy controls on the GHQ-12. 39 % of individuals with COPD scored above the threshold score to detect caseness, in those individuals who attended an outpatient clinic over a 4-week period compared to 17 % healthy controls. Although no significant differences were found in this group, individuals diagnosed with bronchiectasis did score highly on the GHQ-12. 25 % of these individuals scored above the threshold, revealing that some of the individuals appeared to have underlying psychiatric problems, according to this questionnaire, compared with patients attending an outpatient clinic compared to 20 % healthy controls. No significant difference was found between individuals diagnosed with asbestosis compared to their healthy counterparts. However, interestingly 25 % of these individuals did score above the threshold score, revealing that a minority of the individuals, according to this questionnaire, appear to have psychiatric problems compared to 12 % healthy controls. The Beck Depression Inventory measuring depression Individuals diagnosed with asthma, COPD, bronchiectasis and asbestosis revealed significantly greater episodes of depression compared to their healthy counterparts. Cognitive assessments – 2 items derived from the Dan-MONICA data: concentration and memory problems Individuals diagnosed with asthma, COPD, bronchiectasis and asbestosis were significantly more likely to report concentration problems compared to their healthy counterparts. These individuals did not however obtain a mean score greater than the comparison score in the Dan-MONICA study. 205 Individuals diagnosed with asthma, COPD and asbestosis were significantly more likely to have greater memory problems compared to their healthy counterparts. These individuals also scored above the threshold core as revealed in the DanMONICA study. Individuals diagnosed with asbestosis were shown to have significantly greater memory problems but scored below the threshold score. Associations between sleep disorders and behaviours, daytime sleepiness, quality of life, mental health, depression and cognitive functioning. Significant associations were observed across all four respiratory groups, both positive and negative. Individuals diagnosed with asthma revealed that as their self-reported sleep problems increased so did the score on their daytime sleepiness and General Health Questionnaire-12. Their QoL was lower and their feelings of depression increased, too. Individuals diagnosed with COPD revealed that as their sleep problem (DIMS and other disorders during sleep) increased, their self-reported cognitive complaints were greater, too. Individuals diagnosed with bronchiectasis revealed that as their sleep problems (SDB, other disorders during sleep and other disorders during the day) increased, their score in general health increased, they reported higher on the BDI. Their QoL was reduced and they had reduced cognitive functioning. There were no significant associations found in the groups of individuals diagnosed with asbestosis. 4.2.1Main findings and comparisons with other studies This section discusses the main findings and compares them to the studies that have been discussed in the literature review. The section will be arranged in terms of the data analysis where by sleep problems and sleep disorders will be discussed first, followed by daytime sleepiness, QoL, General health Questionnaire-12 and Beck Depression Inventory and finally cognitive functioning, for each respiratory group. 206 Asthma Sleep problems and sleep disorders In this study, individuals diagnosed with asthma reported greater sleep problems compared to healthy controls. Asthma causes a variety of respiratory problems which can impair the QoL and lead to sleep disturbances. The individuals diagnosed with asthma in this study reported problems with disorders of initiating and maintain sleep; sleep associated with disordered breathing, sleep related disorders/behaviours occurring during the day and time required for sleep and sleep duration. These results are supported by Janson et al (1990) and Shah et al (1997) who reported that the most common sleep disturbances amongst asthmatic patients were early morning awakening, difficulty in maintaining sleep, excessive daytime sleepiness, nocturnal wakefulness and nocturnal breathing problems. The fact that individuals reported waking during the night in this study could be due to the fact that the individual’s asthma woke them due to their symptoms relating to asthma. This problem has been explored by Turner-Warwick (1988) who showed that individuals diagnosed with asthma reported they woke at least once a week due to their symptoms and woke frequently throughout the week. Individuals diagnosed with asthma in the present study reported poor sleep quality Caterall et al (1982); Montplaisir et al (1982); Fitzpatrick et al 1991) highlighted the problem of sleep quality in those individuals diagnosed with asthma. Asthma per se can disrupt sleep, these factors being troublesome day-time and nocturnal symptoms. Sleep quality maybe further reduced especially if the individual experiences an asthma attack during stages 1 and 2 and NREM sleep. Individuals will often report feeling unrefreshed and fatigued in the morning and will experience excessive sleepiness in the morning after awakening; this is supported by the work of Ravenscroft and Hartmann (1968). In this study individuals also reported staying awake in bed before they fell asleep; this may be because those with asthma enjoy far less of the deep and restful sleep stages 3 and 4 than those without asthma and spend far more time awake (Hindmarch, 2003). 207 Daytime sleepiness Although non-significant scores were observed in this group, individuals diagnosed with asthma did obtain a mean score that was greater than their healthy controls. These individuals also bordered on showing similar ESS scores classified with mild OSAS according to the ESS normative scores (appendix 11). These individuals did report, however, being significantly sleepier during the day and leisure time on the BNSQ. Further analysis of the data also revealed significant associations between other sleep disorders during the day and during sleeping and excessive daytime sleepiness. Excessive sleepiness is a serious condition, which does not just affect the individual but also his or her colleagues, friends and family; it can be life-threatening in a variety of conditions from work, to driving and to developing other co morbidities (Mitler et al, 2005). Some efforts have been made to highlight the nature of sleep disturbances in individuals diagnosed with asthma and its effects on daytime performances (Janson et al; Fitzpatrick et al, 1991) and Vir et al (in press). The effects of daytime sleepiness are underrated in such individuals (Sharpley, 1996). The effects that daytime sleepiness has upon the individual are detrimental in the sense that they affect the daily performance of individuals diagnosed with asthma in psychosocial performances and cognitive functions (which will be discussed later in this section), mood swings and emotional distress and reduced leisure activities thus resulting in reduced physical and mental well-being. QoL The relationship between asthma and QoL in adults is believed to be important but has not been well studied, according to Archea et al (2006). In this study, individuals diagnosed with asthma reported reduced QoL on all but the pain scale of the SF-36. Perhaps the reasons for such low scores could be that psychological distress is more frequent in those with asthma and thus at risk of being anxious and more likely to feel depressed. The transformed mental health component score was also significantly lower than healthy controls and the reason for this could be that such individuals always feel a lack of control over their health; such 208 individuals have been shown to score significantly lower on the SF-12 scales, too, as shown by Adams et al (2004). Further analysis of the data in this group revealed significant associations between the selected sleep categories and the two SF-36 component scores, thus providing further support for the knowledge that as the various sleep problems increase in an individual this can then have a knock on effect on the individuals physical and mental QoL. General Health Questionnaire-12 and Beck Depression Inventory In individuals diagnosed with asthma, mental health was reported significantly lower in relation to healthy controls both on the SF-36 and the GHQ-12. The reasons for this occurring could be due to several factors. Individuals diagnosed with asthma often report feelings of anxiety and depression, as shown by Janson et al (1994). It is important to note that the severity of the asthma status was not monitored but studies have shown that those with severe asthma do also display the same relationship between psychological status and morbidity (Cooper et al, 1997). Individuals may also report feeling mentally worse and more depressed because of the distress that perhaps the individual experiences during an attack. Individuals may also have insufficient knowledge, unable to manage exacerbations and have poor adherence to treatment which can also cause great anxiety; these issues have been briefly explored by Neville et al (1991), Padget and Brodsky (1992) and Reed et al (1985). Further studies have shown that panic and fear occur at higher rates in people with asthma compared to non-asthmatic individuals, as shown by Kinsman et al (1973) and Dirks et al (1973). Suggestions to explain why individuals diagnosed with asthma have been shown to have higher rates of panic and fear is firstly the feeling of breathlessness (Bass and Gardner, 1985), individuals who are predisposed to anxiety and depression (Bass and Gardner, 1985) and those diagnosed with bronchial asthma have shown to report greater feelings associated with anxiety and fear (Lyketsos et al, 1984). In the present study, 83% of individuals with asthma scored above the threshold score in the GHQ-12 and 50 % of healthy controls scored above the threshold score, 209 these individuals who scored 83% above the threshold score help towards the explanation of the association between asthma and morbidity in terms of poor social functioning (Sibbald, 1989; Campbell et al, 1995) and it has been proposed that perhaps psychiatric morbidity may decrease an individual’s ability to care for themselves, as shown by Sibbald (1989). Further studies which support this is the work conducted by Vamos and Kolbe (1999) who found that 25% of their sample had possible caseness for anxiety, lower than the present study and 11% had caseness for depression. The associations conducted on the data in the present study revealed that as other disorders during sleep and other disorders during the day increased so did the score on the BDI. Cognitive functioning Individuals diagnosed with asthma reported greater concentration and memory problems compared to healthy controls. Reasons why individuals may experience greater memory and concentration problems have been explored by a few published studies. Individuals who report greater sleep disturbances associated with DIMS also report excessive daytime sleepiness which has an impact on cognitive functioning. Daytime cognitive functioning is worse in individuals diagnosed with asthma and usually shown to take longer to complete cognitive tasks (Fitzpatrick et al, 1991; Janson et al, 1990). The ATS (1998) has further supported this by studying the consequences of excessive daytime sleepiness and the significant deterioration that it brings in daily performance in individuals diagnosed with asthma, thus having a knock on effect on occupational performance and during leisure activities (Pilcher and Huffcutt, 1996; Smith-Coggins et al, 1994). The associations conducted on the data in the present study did not reveal any significant correlations between any of the sleep subscales and cognitive functioning. COPD Sleep problems, sleep disorders and daytime sleepiness. In the present study, individuals diagnosed with COPD reported significant sleep problems and behaviours compared to healthy controls. Sleep quality is often impaired in individuals diagnosed with COPD (Cormick et al, 1986; Fleetham et al, 210 1982; Brezinova et al, 1982). Individuals in the present study reported waking during the night and snoring more often than their healthy counterparts; these individuals also reported excessive sleepiness during the day and increased daytime napping and staying awake longer in bed before falling asleep. A study by Saaresranta et al (2005) who used the BNSQ to assess sleep problems and behaviours in individuals diagnosed with COPD, showed that those with COPD reported never sleeping well, slept restlessly and feeling tired in the morning. In terms of excessive daytime sleepiness although significant findings were not reported, it did however reveal that individuals diagnosed with COPD reported greater excessive sleepiness, the current data are contradictory in the sense that a study by Saaresanta et al (2005) revealed that individuals with mild to moderate COPD without acute exacerbations do not complain about excessive sleepiness as much as individuals diagnosed with OSAS do. Bellia et al, (2003) has reported, however, that elderly individuals diagnosed with COPD complain more of morning tiredness and early awakenings. Sleep disturbances in individuals diagnosed with COPD is usually related to nocturnal cough, wheezing and shortness of breath due to the worsening of pulmonary mechanics and gas exchange during sleep. This is further supported by Klink et al (1994), who showed where one respiratory symptom was present, such as cough or wheeze, 12% of the sample population reported excessive daytime sleepiness and 39% reported insomnia. With both symptoms present, 23 % reported feeling excessively sleepy during the day and 53% reported episodes of insomnia. Poor quality sleep can be further explained by marked increases in sleep stage changes, frequent arousals and awakening and decreased total sleep time. It is also important to note that individuals with poor quality sleep will not necessarily perceive themselves as having poor sleep, despite that sleep studies in individuals diagnosed with COPD have been shown to have excessive daytime sleepiness, minimally altered sleep quality and sleep architecture (Sanders et al, 2003). One factor that has not been considered but is important to mention is that age related sleep changes can also occur in this group of individuals and studies have shown that sleep quality does deteriorate in the elderly population. 211 A further explanation why these individuals may experience such sleep behaviours is that hypoxemia and hypercapnia are both factors that are likely to contribute to the disturbed sleep of such individuals. The worsening of hypoxemia during sleep in individuals diagnosed with COPD has been documented since the early sixties (Trask and Cree, 1962). This notion of hypoxemia and hypercapnia contributing to disturbed sleep is further supported in a study by Fleethan et al (1982) who showed that individuals exhibited increased arousal frequency during reduced arterial oxygen saturation when they were breathing room air. This also showed that hypoxemia alone does not cause sleep arousals but so does hypercapnia. Further evidence suggests that a change in upper airway resistance during sleep is highest during REM sleep, during wakefulness, stages 2, 3-4 respectively (Ballard et al, 1995). QoL COPD is a progressively debilitating disease. This has been further supported with the results obtained from the SF-36 QoL sub scales. The symptoms which manifest in this condition frequently interfere with various aspects of living, such as work, family roles, socialisation and the general daily activities. The studies mentioned in part 2 briefly touch upon the consequences of living with such a debilitating condition. A survey of individuals diagnosed with COPD showed how COPD is associated with intermittent worsening of symptoms and lung function impairment (Murray et al, 1997; Celli et al, 2004). Not only do the exacerbations of symptoms contribute towards mortality and morbidity but also they considerably affect the QoL experiences by such individuals (Murray et al, 1997; Celli et al, 2004). Another factor which may explain the poor QoL in such individuals is that the symptoms associated with COPD, such as breathlessness, wheezing and coughing can have considerable effects on the physical and emotional and social aspects of a individual’s life. General Health Questionnaire-12, Beck Depression Inventory and cognitive functioning. In the present study, individuals diagnosed with COPD reported significantly reduced mental health and greater feelings of depression; individuals also reported 212 increased concentration and memory problems, compared to healthy controls. In part 2 it has been stated that factors such as cognitive decline and depression influencing sleep disturbances and vice versa have not been evaluated in this condition. It is known that disturbed sleep does lead to poor daytime functioning. Disturbed sleep can affect daytime activities, have a negative impact on QoL, have a negative impact on mental health, increase feelings of depression and cause impairment in cognitive functioning. Again, although age was a factor that was not studied, it is also important to consider the age factor of these groups of individuals. Generally, elderly individuals will naturally show a decline in these areas regardless of matching individuals for age and sex. In the present study individuals revealed that as their self reported sleep problems concerning DIMS and other disorders during sleep increased, they reported experiencing greater problems concerning cognitive functioning. 213 Bronchiectasis Sleep behaviours, sleep disorders and daytime sleepiness Individuals in this group reported worsened snoring, frequent nightmares and excessive sleepiness after awakening and during the day. Although there is no empirical evidence available to support and explain the findings of the present study but from the studies presented in part 2 of this thesis it can be said that the symptoms of bronchiectasis (sputum production, wheeziness, breathlessness and recurring chest infections) can cause nocturnal arousals and can disrupt sleep. Sleep quality maybe be further reduced, especially if the individual experiences respiratory distress during stages 1 and 2 and NREM sleep (Ballard et al, 1995). Individuals will often report feeling unrefreshed and fatigued in the morning and will experience excessive sleepiness in the morning after awakening. This can be further supported by the results of the present study whereby the associations revealed that as an individual’s score on sleep behaviours and problems increased so did their score for excessive sleepiness on the ESS. QoL The QoL reported in the present study was shown to be significantly reduced in individuals diagnosed with bronchiectasis. Studies investigating QoL in relation to individuals diagnosed with asthma and COPD have shown the detrimental effects that disturbed sleep can have on a person’s QoL and how this can affect not only their physical and mental functioning but also relationships with friends, family and perhaps colleagues, too. Further analysis of the present data revealed that as the sleep problems increased so did the individual’s negative perception of their mental health. Poor QoL can also have a knock on effect on the individual’s mood and memory, too. Another reason for why these individuals will report poorly on the QoL assessments is that they feel they do not have any control over their illness and therefore the disease itself controls the individual and dictates what they can do and when. 214 General Health Questionnaire, Beck Depression Inventory and cognitive functioning Individuals diagnosed with bronchiectasis showed that their self-reported sleep problems increased their feelings of depression and caseness for psychiatric problems increased, too, together with poor cognitive functioning. Although there is not an individual study to support these facts, there are, however, particular studies that have researched specific psychological concepts in relation to respiratory diseases (asthma and COPD) and sleep disturbances. This clearly shows the lack of research published in this area to try to fully understand how individuals diagnosed with respiratory diseases cope with their condition on a day-to-day basis and more importantly how the condition affects their sleep and the psychological consequences for their daily life. An important finding from the GHQ-12 showed that 25 % of individuals in this group diagnosed with bronchiectasis showed caseness for psychiatric problems in the present study and 20 % of healthy controls. According to the GHQ-12, caseness detects psychiatric impairment and is relevant to those attending outpatient clinics. The present study, however, did not examine this concept. The fact that caseness is present for the other 3 respiratory conditions is evidence that this is not something that may be present in just those attending an outpatient clinic but perhaps the disease itself may also manifest these psychiatric problems. Poor cognitive functioning is often present where disturbed sleep is reported. Poor sleep can usually have an impact on the cognitive functioning of the individual. Asbestos related conditions Sleep behaviour, sleep disorders and daytime sleepiness The results obtained within this group were interesting and it is important to note the sample size of the group was small. Individuals diagnosed with asbestosis did not report any significant sleep problems, sleep disorders and daytime sleepiness, compared to their healthy counterparts that would suggest that their condition was perhaps causing these disturbances. The sleep problems that these individuals did report were that they slept slightly longer, took longer naps and started snoring at a 215 later age compared to their healthy counterparts, which is nothing unusual in this group specifically in terms of age. These sleep problems could be age related rather than related to the individual’s disease. Clinically, most individuals diagnosed with asbestosis are asymptomatic for at least 20 to 30 years after the initial exposure. Asbestosis has been referred to as a monosymptomatic disease because of the most distressing symptom, dyspnoea. Dyspnoea is terrifying to the individual and the attack itself can cause sleep disturbances and leave the individual feeling excessively sleepy during the day. QoL In the present study, individuals had reduced QoL compared to their healthy counterparts. A number of reasons can be put forward why these individuals reported poor QoL; firstly, age is a factor, although not explored, which could have had a significant impact on both the physical and mental elements of the individual SF-36 scales. Socio-economic factors were not analysed in the present study but can also have an impact on individual QoL. The group of people who were of a retired age showed that such an impact can cause poorer QoL. The disease itself is an important factor; dyspnoea itself is a very distressing symptom and may cause the individual to feel that they are not in control of their symptoms and an attack can occur at anytime. Asbestosis causes persistent cough and sputum, the cough is usually dry; chest tightness and pains are not uncommon. General Health Questionnaire-12, Beck Depression Inventory and cognitive functioning Although individuals diagnosed with asbestosis did not report significant differences in general health compared to healthy controls, 25% of individuals diagnosed with asbestosis did, however, score above the threshold for the GHQ-12 and had caseness for psychiatric problems and 12 % healthy controls. These psychiatric problems are reflected in the BDI scores, whereby significant differences were observed and these individuals did report greater feelings of depression compared to their healthy counterparts. Due to the fact that there are no previous data available to explain why 216 these individuals experience elevated levels of depression and poor mental health this may be because living with the disease has a negative impact on the person. In terms of poor cognitive functioning, this may be due to age related cognitive decline rather than specific sleep disturbances, which were not observed in this group. Further analysis of the data in this group revealed no significant associations between the sleep disorders and behaviours, daytime sleepiness, quality of life, mental health, depression and cognitive functioning. 4.3 Evaluation of methodology and suggestions for refinements in further studies The return rates (70%) of the sample of individuals diagnosed with respiratory diseases were relatively high and those of the healthy participants recruited into the study. Individuals and healthy participants were informed of the importance of returning completed questionnaires, individuals and healthy participants were willing to participate and return questionnaires, most probably due to the nature of the research and an opportunity to discuss their sleep problems. This is suggestive of the fact that those who had problems with their sleep were more likely to respond, compared to those individuals and participants who felt that they did not have problems with their sleep. As well, the composition of the samples of the participants and healthy controls in terms of sex and age allowed direct comparisons of the different groups. In terms of questionnaire studies there are a number of limitations in general, mainly regarding the subjectivity of the data collected and the possibility of bias in the responses of the participants. In the current study there is no reason to assume that individuals and participants would be motivated to provide misleading and false information concerning their sleep, QoL and psychological functioning. The author’s main concern, however, in terms of responding to the individual items is to the content of specific questions, particularly concerning mental health and depression. The results suggest that individuals and healthy participants would not report misleading information concerning their mental health. 217 Another problem concerning a survey design is in the interpretation of some of the individual items or particular questionnaires. The main concern was possible vagueness of item wording or ambiguity, regardless of attempts by the original author of the questionnaire to make it readily understandable and acceptable by those completing it. This was particularly the case in the interpretation of the BNSQ questionnaire. There were no specific instructions how to score the individual items in the questionnaire. This lack posed the problem of whether or not the items on sleep had been interpreted and scored appropriately. Although individuals who had participated in the survey had scored highly in some areas of the BNSQ, nevertheless, in order to further clarify any specific sleep disorders, clinical evaluation was needed to usefully diagnose sleep disorders. Within the BSNQ was a free response question for which the participants (individuals and healthy counterparts) could voice their own personal problems concerning sleep. The author feels that this information could have been utilised, perhaps by using qualitative methods of analysis to gain a deeper understanding of the patient’s perspective. The data collected from the questionnaires can be viewed to be useful for preliminary screening purposes only; these data can further lead to a more detailed enquiry including objectively measuring sleep. This is most certainly the case where individuals reported disturbed sleep due to SDB and sleep disorders occurring during the night, e.g., bruxism, nightmares and sleep talking; these need a careful special investigation to justify a definite diagnosis. Data was also collected on whether individuals diagnosed with respiratory diseases had any other co-morbidity. Although there was a specific set of exclusion and inclusion criteria followed by the researcher, individuals did, however, report having other disorders and or diseases that may have impacted on their responses to some of the questionnaires. The data collected resulted from asking whether or not individuals had any current illnesses or physical disorders or have had such in the past 3 months and any illness or physical disorder that participants have ever had. These, when the participants answered ‘yes’, could have been associated with sleep disturbances and many of the other responses on the assessments concerned with 218 mental health, QoL, depression and cognitive functioning. It would be interesting to evaluate the relative contribution such factors make to the existence of sleep problems in these individuals. Taking these factors into account, however, in the detail that some of them would have required would have meant going beyond the time and the resources available to the author. Further data on height, weight, BMI, smoking status, ethnicity, education and occupation was collected. During the systematic review of the literature, it was noted that there were studies that dealt with some of these factors in relation to respiratory diseases (asthma and ethnicity, smoking and occupation). It would have been interesting to see how these factors (occupation and education) contribute towards the individuals QoL, mental health and depression. Further data was also collected on whether or not an individual was aware of any family member (mother, father, sibling, partner, grandparents) who were known to have experienced sleep disturbances. The issue concerning the statistical tests used to analyse the data is also important. Although the findings from the tests of differences and associations appear to be meaningful it would be interesting to see whether the same pattern of results emerge with a larger sample of individuals. In addition, some type 1 errors may have occurred due to the large number of comparisons conducted within the phase 1 data. Having said this, the majority of the comparisons were significant at the 1% level or greater. The findings show the importance of considering individuals sleep, QoL and psychological well-being as well as acknowledging their clinical diagnosis. It has been suggested by research that individuals do tend to under-report their disturbed sleep (Van Keimpema, Ariansz, Nauta and Postmus, 1995). In clinical practice, administering a simple sleep questionnaire should become routine as part of the clinical assessment of the patient’s disease. Considering the patient’s sleep problem will also help in improving the patient’s overall condition. 219 4.4 Feasibility In general, the questionnaires used were shown to have face validity and were acceptable to the individuals diagnosed with respiratory diseases and the healthy controls. The questionnaires themselves were initially piloted to confirm that they were user friendly. One of the main problems, however, that did arise from the study was that individuals complained about the size of the questionnaire booklet (appendix 2). Generally the questionnaire was accepted and the author assisted those individuals who did not wish to complete the questionnaires themselves. Another problem that did arise, however, was that a minority of the individuals approached in clinics were illiterate and refused to take part; the author was not aware of this prior to collecting the data but the matter was discussed and to overcome this problem, individuals who refused to take part were asked whether they wouldn’t mind responding while the questionnaire was completed for them but not pressured. Every effort was made to ensure that no bias from the author found its way into these dictated responses. Individuals were also offered the opportunity to complete the questionnaire in their own time but many chose to complete the questionnaire in clinic and so could ask any questions which may have arisen during the study phase. It is accepted that as a result of the diverse contexts in which these data were collected some uncontrolled variations may be present, perhaps having an effect on which comparisons were found to be significant and which were not. 4.5 Future research It is expected that in research such as that described in this thesis, which is concerned with a relatively unexplored field, that many issues will arise which need further investigation. A number of research possibilities have already been identified and many more could be suggested regarding sleep disorders in general, and those related to disturbed sleep in individuals diagnosed with respiratory diseases. Basic topics which need to be investigated by specialist respiratory clinicians include: • What is the range of sleep disorders in respiratory disease? What are their effects on the management of individuals diagnosed with respiratory 220 diseases? Tests of associations showed that individuals diagnosed with respiratory diseases complained of increased excessive daytime sleepiness as their sleep problems during the night and during the day worsened. How can excessive daytime sleepiness be diagnosed and monitored in such individuals? • How can clinicians ensure that the individual’s disturbed sleep is not due to their disease but a factor that has been present prior to the onset of the disease? • Can certain treatments have negative consequences on the individual’s quality of sleep? • Sleep studies to monitor when respiratory attacks occur and how these impact the individuals day-to-day functioning. How can these nocturnal attacks be managed? Are there any triggers which cause these attacks? • How do the individual’s diseases impact their mental health, QoL, feelings of anxiety and depression and cognitive functioning? Are there specific tests which can be performed to gauge what the individual has scored before and after treatment? Other topics for research of a non-respiratory nature include: • The QoL of individuals diagnosed with respiratory disease using qualitative methods to gain a deeper understanding of how the disease impacts them as an individual. • Age related comparative studies of individuals diagnosed with asbestosis and other respiratory diseases to understand the normal age related cognitive decline, sleep decline and physical functioning decline in comparison to those diagnosed with asbestosis. • To further explore the impact of living with asbestosis and bronchiectasis and use both objective and subjective methods to explore sleep quality. 221 • To further explore variables related to depression and the disease and whether these impact sleep quality. • Whether or not ethnicity, occupation and education are associated with specific sleep behaviours and problems and the impact on the psychological functioning of specific respiratory groups. Some of the suggestions made would require the expertise of both a respiratory physician and psychologist with a special interest in sleep medicine to work together. Assessments of the severity of the sleep problems in general and also treatment evaluations have to take into account cognitive and behavioural aspects (not just physical considerations) because they are what matter most to the individual’s wellbeing. Skills relating to psychological functioning are essential in preventative and treatment programmes for the sleep disorders which are not physical in origin and also in aspects of management of those which are, these being counselling and being able to manage anxiety in such individuals. The present findings confirm the high levels of anxiety felt by such individuals. It is also important to state that the standard measures of lung function do not necessarily relate to the severity of psychological functioning. The psychologist’s role is also particularly important in the investigation of the relationship between sleep disturbances and physical functioning. One of the basic problems with certain sleep problems is whether sleep disturbances cause daytime problems or whether the sleep problem is caused by behaviour that is already disturbed. When the sleep problem is behavioural in nature this issue may be settled by careful developmental studies of the sequence of events by treating one problem to see the effect it has on another. It is important to take note of these possibilities and to understand that the present study has only scratched the surface and highlighted the importance of understanding and acknowledging that individuals diagnosed with respiratory diseases do have disturbed sleep in many of the areas highlighted by the BNSQ. Disturbed sleep is also very detrimental to the individual’s psychological well-being, in particular their general health, mood, QoL and cognitive functioning. Future research needs to 222 include objective measures to further explore the disturbed sleep patterns of such individuals and to collect normative data which would be highly useful in exploring these factors and how they may affect the individuals sleep and psychological functioning. ************************************ 223 224 Acknowledgement of the limitations in both the literature review and methodology. Limitations in the literature review A more thorough search of the literature may have identified additional relevant research. Additional strategies which could have been used include: searching additional databases, using additional search terms including additional Mesh and Thesaurus terms, and searching for grey literature by contacting experts. Further attempts at refining the search strategy as the literature search progressed would have helped identify all relevant studies. In addition, further assessment of the quality of the articles selected for the literature review could have been more rigorous including utilisation of the Critical Appraisal Skills Programme (CASP) checklists. This combined with more rigorous use of inclusion and exclusion criteria of studies would have been useful in producing a higher quality review of the literature. Limitations in the methodology General strengths and weaknesses of the questionnaire method will be discussed first and then strengths and weaknesses of the specific questionnaires used in the present study. Advantages of using a questionnaire method • Responses are gathered in a standard way, so questionnaires are more objective, certainly more so than interviews. A study information sheet was provided to the participants with the questionnaire so that they understood what was expected of them. • Generally it is relatively quick to collect information using a questionnaire. However, in some situations they can take a long time not only to design but also to apply and analyse (Biemer & Lars, 2003). • Potentially information can be collected from a relatively large sample. This potential is not often realised, as returns from questionnaires are usually low, (Biemer & Lars, 2003). However return rates can be dramatically improved if the questionnaire is delivered and responded to perhaps with stamped addressed envelopes, (Biemer & Lars, 2003). 225 Disadvantages of using a questionnaire method • Questionnaires are usually used to obtain information retrospectively, so are dependent on accurate recall by participants. The Basic Nordic Sleep Questionnaire, Epworth Sleepiness Scale, General Health Questionnaire-12, The Short form-36, Beck Depression Inventory and the 2 items from the Jennum and Sjol study all required the participants to recall information about their sleep, health, and quality of life, mood and memory over a certain period of time. Along with this, most of the participants were elderly too and studies have shown that there is generally a cognitive decline in the elderly which may affect the recall of items in the questionnaire, (Fowler & Cannell, 1996). • Questionnaires are standardised so it is not possible to explain any points in the questions that participants might misinterpret. This could be partially solved by piloting the questionnaire with the particular group of participants recruited for the study. For the present study the questionnaire was initially piloted with a group of 60 participants from Portsmouth Hospitals NHS Trust to ensure that the questionnaire itself was adequate to administer in such a population. • Open-ended questions can generate large amounts of data that can take a long time to process and analyse. One way of limiting this could be to limit the space available to participants so their responses are concise or to sample the participants and survey only a portion of them. In the present study participants generally ticked boxes and had the opportunity to speak of their concerns regarding their sleep for just one question. • Respondents may not be willing to answer the questions. They might not wish to reveal the information or they might think that they will not benefit from responding perhaps even be penalised by giving their real opinion. Participants should be told why the information is being collected and how the results will be beneficial. Those participants who did participate in the present study did complete the questionnaire fully and were more than happy to discuss their problems during clinic times with the primary researcher. 226 Specific questionnaires used in the present study Sleep related questionnaires: In the present study the Basic Nordic Sleep Questionnaire (BNSQ) was used to collect data on sleep from the participants. This questionnaire is designed to question the participants sleeping habits and disorders for the past three months. It is a selfadministered questionnaire and has been used widely in a variety of studies performed in Nordic countries during the last several years and has proved to be a valid tool (Partinen & Gislason, 1995). However, although the BNSQ has served as a basis in many epidemiological studies performed in the Nordic and other countries, one of the disadvantages of using the BNSQ is that it questions the participants sleeping habits over the last 3 months which could be considered to be a relatively long recall period. The Pittsburgh Sleep Quality Index (PSQI) may have been a more appropriate choice of sleep questionnaire. The PSQI is also a self-rated questionnaire but assesses the participant’s sleep over the last month rather than 3 months in the base of the BNSQ. The BNSQ assess four main areas of sleep (dysomnias, parasomnias, medical/psychiatric and proposed sleep disorders) and gives an overall score where as the PSQI generates seven component scores (sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication and daytime function) and the seven components yield one global score. Other questionnaires: In the current study the author did not select a disease specific questionnaire to measure the severity of respiratory diseases. Perhaps, in hindsight this would have been an appropriate addition to understand the severity of the diseases of participants. However, it was important not to overburden participants with too many questionnaires. A useful additional questionnaire to assess the severity of symptoms in participants living with a respiratory disease specifically asthma, COPD, bronchiectasis and asbestosis and related illnesses would have been the St George’s Respiratory 227 Questionnaire (Jones, Quirk & Baveystock, 1991). The questionnaire is designed to cover the participant’s recollection of their symptoms over a preceding period that may range from one month to one year. It is not designed to be an accurate epidemiological tool; its purpose is to assess that participant’s perception of their recent respiratory problems. It also addresses the participant’s current state. The usefulness of collecting this data would have meant a greater insight into how the individual copes with their condition and how it directly affects their sleep, QoL, mood and memory. In the current study the Beck Depression Inventory (BDI) and the General Health Questionnaire (GHQ) have been used to collect data relating to mood. A more suitable alternative to these two questionnaires could have been the Hospital Anxiety and Depression scale (HADS) developed by Zigmond and Snaith (1983). The HADS may have been better suited because it is a reliable instrument for screening for clinically significant anxiety and depression in participants attending a general medical clinic, therefore the researchers would have had a better understanding of whether anxiety and depression was due to the lack of sleep, coping with the condition or generally having to attend regular clinic appointments concerning their condition as the HADS would have highlighted this. The HADS has also been shown to be a valid measure of the severity of these disorders of mood. In comparison the BDI measures the behavioural manifestations of depression but some of the questions in the BDI maybe viewed as inappropriate in an already anxious and depressed population because there are questions which are sensitive and may cause participants to alter their responses. The GHQ is also designed to detect psychiatric disorders among participants in community settings and non-psychiatric clinical settings such as primary care or among general medical outpatients. In the present study participants were recruited from an outpatient’s clinic and with no psychiatric illnesses. A further change could be implemented by replacing the two cognitive items by Jennum and Sjol with the Cognitive Failures Questionnaire (CFQ) developed by Broadbent, Cooper, Fitzgerald and Parkes, (1982). This is a self-reported assessment designed to measure failures in perception, memory and motor function. The 228 questions are based on the participant’s experiences in the last six months. In comparison to the two items from the Jennum and Sjol study that were used to collect data on memory and concentration in the present study the CFQ has 25 individual items and provides a more comprehensive picture. Further points to consider in this section is that firstly the author acknowledges the limitations of the questionnaire studies, specific aspects to consider are subjectivity of interpreting the items and scoring items, researcher bias when administering the questionnaire. The current questionnaires used to collect the data in the present study had varying time periods to which collect the data from, for example the BNSQ is designed to question the patients sleeping habits and disorders for the past three months. Both the SF-36 and GHQ is used to question the QoL of patients over the last 4 weeks. It is important for all the questionnaires to have the same time period for which the data needs to be collected. Alternative methods to implement into a future study. A further method which would have been useful to incorporate into the study if there had been funding made available during the project was the actigraph. The actigraph could have been deployed as a tool for investigating whether participants who reported disturbed sleep through the BNSQ were also shown to have disturbed sleep using an objective measure. It is a non-invasive method of monitoring human rest/activity cycles and is worn in the shape of a watch on the wrist of the nondominant arm. Actigraph are useful in determining sleep patterns and circadian rhythms; they can also be worn for weeks at a time. There are several factors that would need to be considered when using an actigraph in a study, these being the element of cost, the type of device to be used with the study population, for example the size and weight of the device, durability and water resistance, the flexibility of the device, for example the sleep parameters measured, the features of the device and validating the device in the prospective study population. As there was also a relatively large sample recruited across the four respiratory groups, this would be very costly too. 229 A sleep diary would also be needed to ensure that the actigraph data corresponds to the diary times and vice versa. These tests are useful for measuring and assessing daytime sleepiness in situations where a laboratory or a sleep latency test is not appropriate. The actigraphs can be used to clinically evaluate insomnia, circadian rhythm sleep disorders and excessive sleepiness and restless legs syndrome. Adding a sleep diary would have provided further data on the individuals sleep and this could have been used to closely analyse the BNSQ and see whether the individuals comments in their sleep diary match up to those in the BNSQ. Actigraphy has not been traditionally used in routine diagnosis of sleep disorders but is increasingly being used in sleep clinics to replace full polysomnograpghy. There are limitations for using the actigraph such as battery usage, the weight of the unit and water resistance qualities. The advantages being that it has watch like functionalities so that the device is more attractive to the user, user input so the wearer is in control of the device. Some of the individuals within the present study may not have consented to using an actigraph as they would have felt it is something else that they need to consider on top of managing their condition. 230 The following table highlights the advantages and disadvantages of the questionnaire method versus the actigraph. Table 1: The advantages and disadvantages of the questionnaire method versus the actigraph. Actigraph Questionnaire method Advantages Accurate indicator of physical activity Standardised therefore objective Low burden in the participant Quick to collect data Non-invasive technique Can collect large amounts of data Provides feedback Easy to administer Less reactivity – influence behaviour Disadvantages Moderate cost. Participants may forget important events Difficult to assess large samples. Due to standardisation-not possible to explain any Water activities and static activities may be a problem to engage in. points to participants. Open ended questions can generate large volumes Non-criteria for what equations and/or cut off of data. points to use. Lengthy time to code, analyse data. Worn for at least 10-14 hours per day. Superficial answers. Charge and download data. Responder bias. Another important factor to consider is the sample size of the current study. The author acknowledges the small sample size within the bronchiectasis and asbestosis and related conditions group in the present study. Collecting larger sample sizes may have yielded different results and therefore different interpretations of the data. 231 Larger sample sizes may have provided more reliable findings within the clinical population. Furthermore, the following factors could have been incorporated into the study; • Analysis between groups with respiratory diseases could have been built into the design of the study • Predictions into the direction of results could have been made in places • Discussion of alternative scoring methods of some questionnaires • Possible type 1 errors and correcting for multiple comparisons. 2. Explicit synthesis of her results in the discussion and within the wider literature Sleep Generally individuals diagnosed with respiratory diseases specifically asthma, COPD and bronchiectasis reported greater problems associated with sleep in comparison to their healthy counterparts. All four respiratory groups also reported excessive daytime sleepiness in comparison to their healthy counterparts. Psychological functioning All four respiratory disease groups (asthma, COPD, bronchiectasis and asbestosis and related illnesses) reported to have poorer psychological functioning across all the psychological assessments (SF-36, GHQ-12, BDI and the two cognitive items) thus reporting lower QoL scores, lower mood and poorer self reported memory and concentration compared to their healthy controls. Associations between sleep and psychological functioning Generally significant associations were found between sleep disorders and measures of psychological functions. Individuals diagnosed with asthma, COPD and bronchiectasis reported to have significant associations between sleep disorders and behaviours, daytime sleepiness, QoL, mental health, depression and cognitive 232 functioning. No significant associations were observed with individuals diagnosed with asbestosis and related illnesses between sleep disorders and daytime behaviour problems. One of the explanations for this is that the sample size for this particular group was relatively small compared to the other three respiratory disease groups. In summary, the present study supports the literature presented in this thesis highlighting the fact that those individuals diagnosed with respiratory diseases especially asthma, COPD and bronchiectasis are more likely to suffer from sleep disturbances and poor psychological functioning compared to their healthy counterparts. The studies presented within the literature review were limited as the author could only find those which represented asthma and COPD, however they do provide a great insight into how individuals living with such conditions may have poor sleep and how this can affect them the individual on a clinical basis but also from a psychological process in terms of poor QoL, poor general health, low mood and generally poor cognitive functioning. The studies in the literature review also provided greater insight into the various methods that have been used to collect such data in such a clinical sample population and draws upon the various methods that have been used to collect data. The current study plays an important part in bridging the gap between studies which focus upon the clinical aspects of living with a respiratory diseases and the consequences that this may have on the individuals sleep whereas the present study focuses upon these factors too but from a subjective point of view. So how does the present study help in terms of clinical care? The findings from the present study highlight several factors these being: the need for further research; the need for further management of symptoms in acute and chronic conditions, the need for a screening tool to measure whether individuals with a specific diagnosis especially respiratory diseases have disturbed sleep; the need for further training of medical and allied health care staff in managing such conditions; wide use of referring individuals to specialists sleep clinics; understanding the individuals subjective needs as well as clinical needs, for example the implications of being diagnosed with a specific disorder and how this can affect a person’s day-today functioning especially adhering and complying to medication usage and 233 understanding of their diagnosis. The implications of the findings from the present study will be discussed in the next section. 3. Clear conclusions showing how they are directly informed by the results In conclusion, in general, individuals diagnosed with respiratory diseases showed a significantly greater number of sleep problems then their matched controls from the general population. From a psychological perspective individuals diagnosed with respiratory diseases across all four groups reported greater reduced psychological functioning (QoL, mental health, mood and cognitive function) compared to their healthy controls. Significant associations between sleep disorders/behaviours and psychological functioning were found in individuals diagnosed with asthma, COPD and bronchiectasis but no significant association were found in the group diagnosed with asbestosis and related illnesses. Implications of findings: The need for further study It is important to further investigate this area as highlighted in the thesis. There are factors which have not been considered which have been mentioned earlier, for example collecting further lifestyle factors to include in the analysis and to ensure that previous episodes of clinical sleep disturbances are also noted. Addition of different disease specific questionnaires can also be included to measure the severity of the disease. The need for further management of symptoms in acute and chronic conditions It is important for clinicians and allied health care staff to be able to manage the individuals condition. This is not only from a clinical perspective for example monitoring the individuals diagnosis and prognosis but, also from a subjective perspective for example, understanding what the individual must be going through outside of the clinical setting and how the diagnosis is affecting their psychological well-being. Both Clinical staff and allied health care staff should be able to offer 234 advice and a suitable referral should the need arise to visit a health psychologist who has been trained to work with individuals living with acute and chronic conditions. The need for a screening tool to measure whether individuals with specific diagnosis especially respiratory diseases have disturbed sleep. The present study has highlighted the need for a tool within clinical practice to measure an individual’s sleep regardless of their condition to screen for any sleep problems. Within respiratory medicine, most patients who may have OSA are usually given the ESS which is quick and easy to administer and score by the clinician to use within the diagnosis process. The author believes that a sleep specific test regardless of the patient’s condition should be incorporated into clinical practice so that not only the individual’s condition is managed but also their sleep disturbances too from the onset. The need for further training of medical and allied health care staff in managing such conditions. Generally within the UK, respiratory medicine is the only branch of medicine which considers sleep medicine as a sub speciality and it is only emerging as an important branch in recent years. Various authors generally from a psychological background have conducted research highlighting the need for further training and understanding the importance of sleep generally as well as in the disease process. Referral of individuals to specialist sleep clinics. Sleep clinics within the UK have been relatively rare until recent times but are slowly emerging in both private and clinical settings. General Practitioners who now see individuals with suspected sleep problems can be referred on to specialists either privately or through the National Health Service by their General Practitioner. It is also important to ensure correct diagnosis of the individual’s condition and have suitable treatments set in place and then to see if the individual is still reporting disturbed sleep. 235 Understanding the individual’s subjective needs such as psychological well-being, quality of life, mood and memory as well as clinical needs such as managing and treating the diagnosis. The present study has highlighted the importance of understanding the individual’s subjective needs which are considered to be of importance to the individual as well as the clinical needs of their respiratory condition. The individual should be able to inform their clinician or allied health care staff of their psychological well-being and how they are coping with their condition and the affects that their condition is having on their well-being in general. The implications of being diagnosed with a specific disorder, how this can affect a person’s day-to-day functioning especially adhering and complying to medication usage and understanding of their diagnosis. The present study has highlighted the fact that poor sleep, excessive daytime sleepiness, may be associated to the individuals QoL which results in poor QoL, poor general health, anxiety and low mood which affects the individual’s memory and concentration. These factors can also affect the way in which the individual copes with their condition, for example the individual may not be able to recall how to manage their symptoms if a respiratory attack was to occur, how to take their medication because they were too tired to understand and listen. Furthermore those individuals with psychological problems will need specialist care to be able to manage their psychological symptoms appropriately. 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Zigmond, A.S., Snaith, R.P. 1983, "The Hospital Anxiety and Depression Scale". Acta Psychiatrica Scandinavica, vol. 67, pp. 361-370. 255 Appendices Appendix 1: Key terms and databases used for the literature review. Appendix 2: Patient invite letter with consent form for individuals Appendix 3: Patient information sheet for individuals Appendix 4: Study questionnaire Appendix 5: Participant invite letter with consent form for healthy participants Appendix 6: Participant information sheet for healthy participants Appendix 7: Ethics Letters Appendix 8: The National Statistics Socio-economic classification: user manual Appendix 9: Legend for diseases listed in results section Appendix 10: The British guidelines for asthma management Appendix 11: ESS normative scores Appendix 12: SF-36 normative scores and Z-score calculations Appendix 13: GHQ-12 normative scores Appendix 14: BDI normative scores Appendix 15: Phase 1 raw data SPSS sheet 256 Appendix 1: Key terms and databases used for the literature review. Databases and keyword search terms used for the literature review. Databases used for literature review: Key terms used to gather data: Medline Sleep disturbances. Sleep disturbances & QoL. Sleep Disturbances & Cognitive functioning. Sleep Disturbances & daytime functioning. Daytime functioning, cognitive functioning & QoL. All above combined. Psycinfo-Psyclit Problematic sleep. Sleep disturbances. Sleep and breathing. Sleep and respiratory diseases. Respiratory diseases. All 6 of the respiratory conditions and sleep individually. Sleep apnoeas. Respiratory diseases & QoL. Respiratory diseases & cognition. CINAHL Combination of the above key words were used. The Cochrane Library Asthma. Asthma & Sleep. Asthma, Sleep & QoL. COPD & Asthma. SCOPUS Sleep and respiration. Sleep and daytime functioning. Impaired sleep and daytime function. Quality of sleep 257 Appendix 2: Phase 1 patient invite letter with consent form for patients Respiratory Centre Miss D R Virk PhD Research Student Telephone: 023 9284 5235 [email protected] Trafalgar Building Queen Alexandra Hospital Southwick Hill Cosham PO6 3LY 3rd November 2006. Dear Re: “Sleep Disturbance and General Well-Being in Respiratory Diseases.” We know that you may recently have attended the Respiratory Clinic either at Queen Alexandra or St Mary’s Hospitals. We would be grateful if you would consider helping us in a study to investigate whether sleep disorders occur in individuals with respiratory problems, and whether sleep disorders are associated with daytime sleepiness, reduced quality of life and general mood, memory and concentration disturbance. Information will also be obtained from individuals who do not have respiratory problems. You would be required to either complete a questionnaire and return it by post; or complete it at a visit to the clinic. Before you decide about taking part, please read the enclosed patient information sheet. If you are willing then please complete the slip below along with the completed questionnaire and return it to us in the enclosed pre-paid envelope. Alternatively, if you are given this letter in the clinic, please still complete the slip below along with the completed questionnaire and either return it to us in the enclosed pre-paid envelope, or hand it to one of the investigators in the clinic. If you require further information, please do not hesitate to contact us at the addresses on the information sheet. Yours sincerely Miss D R Virk PhD Research Student ……………………………………………………………………………………… 258 Please tear off this slip and tick one of the following boxes and return in the envelope provided, thank you. I agree to take part in the study (“Sleep Disturbances and General Well-Being in Respiratory Diseases”) I do not wish to take part in the study (“Sleep Disturbances and General Well-Being in Respiratory Diseases”) Name………………………………………………………………………………… Address……………………………………………………………………………… 259 Appendix 3 Phase 1 Patient information sheet for individuals STUDY INFORMATION SHEET Sleep Disturbance and general well-being in respiratory diseases. You are being invited to take part in a research study. Before you decide it is important for you to understand why the research is being done and what it will involve. Please take time to read the following information carefully and discuss it with others if you wish. Ask us if there is anything that is not clear or if you would like more information. Take time to decide whether or not you wish to take part. Thank you for reading this. What is the purpose of the study? Sleep disturbance is a common complaint in various respiratory diseases and can affect an individual’s ability to function properly during the day. Little research has been done in this area. The purpose of this study is to investigate whether sleep problems occur in individuals with respiratory diseases and whether they are associated with daytime sleepiness, reduced quality of life and general mood and memory and concentration difficulties. Information will also be obtained from individuals who do not have respiratory diseases. Why have I been chosen? You have been chosen to take part in the study as you have attended the Respiratory Clinic at Queen Alexandra or St Mary’s Hospital. Many individuals who have attended this clinic will be asked to participate. Do I have to take part? It is up to you to decide whether or not to take part. If you do decide to take part you will be given this information sheet. If you decide to take part you are still free to withdraw at any time and without giving a reason. A decision to withdraw at any time, or a decision not to take part, will not affect the standard of care you receive. What will happen if I take part? If you decide to take part, you will be asked to complete a questionnaire asking about different aspects of any sleep disturbance and daytime sleepiness you may experience, how you rate your quality of life and your general mood and any memory and concentration difficulties you may have. You will then be asked to send 260 the completed questionnaires back to us in a stamped addressed envelope, or return it to the investigating team at your clinic appointment if you completed it on the day. Will my taking part in this study be kept confidential? All information that is collected about you during the study will be kept confidential. Any information about you used for analysis will have your name and address removed so that you cannot be recognised from it. What will happen to the results of the study? It is likely the results of the study will be published in a scientific journal for health professionals. Participants will not be identified in any report or publication. A summary of the results will be made available to all interested participants at the end of the study. Who is organising and funding the research? The research is being conducted jointly by staff at the Respiratory Service, Portsmouth Hospital NHS Trust and The School of Health Sciences and Social Work (SHSSW) University of Portsmouth. Who has reviewed the study? The study had been reviewed by the Isle of Wight, Portsmouth and South East Hampshire NHS Local Research Ethics Committee and the Portsmouth NHS Trust. Thank you for reading this. Contacts for Further Information: Ms Dally Virk Dr A J Chauhan School of Health Sciences and Social Consultant Respiratory Physician Work Trafalgar Building Room 0.302 Queen Alexandra Hospital James Watson Hall Cosham 2 King Richard First Road PO6 3LY Portsmouth PO1 2FR 023 9284 4434 023 9228 6000 ext 1386 [email protected] [email protected] 261 Appendix 4: Phase 1 questionnaire 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 Appendix 5: Phase 1 participant invite letter with consent form for healthy participants Respiratory Centre Miss D R Virk PhD Research Student Secretary: 023 92 845235 [email protected] Trafalgar Building Queen Alexandra Hospital Southwick Hill Cosham PO6 3LY 3rd November 2006 Dear Re: “Sleep Disturbance and General Well-Being in Respiratory Diseases.” We would be grateful if you would consider helping us in a study to investigate whether sleep disorders occur in individuals with respiratory problems, and whether they are associated with daytime sleepiness, reduced quality of life and general mood, memory and concentration disturbance. Information will also be obtained from individuals known to have respiratory diseases. Before you decide about taking part, please read the enclosed patient information sheet. If you are willing then please complete the slip below along with the completed questionnaire and return it to us in the enclosed pre-paid envelope. If you require further information, please do not hesitate to contact us at the addresses on the information sheet. Yours sincerely Miss D.R. Virk PhD Research Student. 286 Please tear off this slip and tick one of the following boxes and return in the envelope provided, thank you. I agree to take part in the study (“Sleep Disturbances and General Well-Being in Respiratory Diseases”) I do not wish to take part in the study (“Sleep Disturbances and General Well-Being in Respiratory Diseases”) Name………………………………………………………………………………… Address……………………………………………………………………………… 287 Appendix 6: Phase 1 participant information sheet for healthy participants STUDY INFORMATION SHEET Sleep Disturbance and general well-being in respiratory diseases. You are being invited to take part in a research study. Before you decide it is important for you to understand why the research is being done and what it will involve. Please take time to read the following information carefully and discuss it with others if you wish. Ask us if there is anything that is not clear or if you would like more information. Take time to decide whether or not you wish to take part. Thank you for reading this. What is the purpose of the study? Sleep disturbance is a common complaint in various respiratory diseases and can affect an individual’s ability to function properly during the day. There is very little research in this area. The purpose of this study is to investigate whether sleep problems occur in individuals with respiratory diseases and whether they are associated with daytime sleepiness, reduced quality of life and general mood, memory and concentration difficulties. Information will also be obtained from individuals who do have respiratory diseases. Why have I been chosen? It is important to compare the findings from those with respiratory diseases and those who do not have respiratory diseases. Once the data has been collected from both groups we shall be able to see how those who live with respiratory diseases are affected in terms of their quality of life, general mood, memory and concentration and whether their respiratory disease has an impact upon their quality of sleep. We will only be able to do this once we have collected data from those without respiratory diseases and compared the findings. Do I have to take part? It is up to you to decide whether or not to take part. If you do decide to take part you will be given this information sheet. If you decide to take part you are still free to withdraw at any time and without giving a reason. A decision to withdraw at any time, or a decision not to take part, will not affect the standard of care you receive. What will happen if I take part? 288 If you decide to take part, you will be asked to complete a questionnaire asking about different aspects of any sleep disturbance and daytime sleepiness you may experience, how you rate your quality of life and your general mood and any memory and concentration difficulties you may have. You will then be asked to send the completed questionnaires back to us in a stamped addressed envelope. Will my taking part in this study be kept confidential? All information that is collected about you during the study will be kept confidential. Any information about you used for analysis will have your name and address removed so that you cannot be recognised from it. What will happen to the results of the study? It is likely the results of the study will be published in a scientific journal for health professionals. Participants will not be identified in any report or publication. A summary of the results will be made available to all interested participants at the end of the study. Who is organising and funding the research? The research is being conducted jointly by staff at the Respiratory Service, Portsmouth Hospital NHS Trust and the School of Health Sciences and Social Work (SHSSW) University of Portsmouth. Who has reviewed the study? The study had been reviewed by the Isle of Wight, Portsmouth and South East Hampshire NHS Local Research Ethics Committee and the Portsmouth NHS Trust. Thank you for reading this. Contacts for Further Information: Ms Dally Virk Dr A J Chauhan School of Health Sciences and Social Consultant Respiratory Physician Work Trafalgar Building Room 0.302 Queen Alexandra Hospital James Watson Hall Cosham 2 King Richard First Road PO6 3LY Portsmouth PO1 2FR 023 9284 4434 023 9228 6000 ext 1386 [email protected] [email protected] 289 Appendix 7: of study Letters from ethics committee for approval 290 291 Appendix 8: The National classification: user manual 292 Statistics Socio-economic Appendix 9: Legend for diseases listed in results section Skin: • For example eczema, psoriasis, acne, rosacea, warts, calluses, candidiasis, crab lice, dermatophytoses, head lice, hirsutism, nappy rash, photodamage, pityriasis versicolor and scabies. Ear, Nose and oropharynx: • For example allergic rhinitis, nasal polyps, oropharyngeal infections and peridontitis. Cardiovascular: • Angina, arrhythmias, cardiovascular disease risk, heart failure, hypertension, myocardial infarction and phaeochromocytoma. Gastro-intestinal system: • Antibiotic-associated colitis, constipation, crohn’s disease, diverticular disease, food allergy, helicobacter pylori infection, irritable bowel syndrome, NSAID-associated ulcers, ulcerative colitis. Obstetrics, gynaecology and urinary tract disorders: • Nocturnal enuresis, premature labour, prevention and treatment of post-partum haemorrhage and priapism. Musculoskeletal and joint diseases: • Dental and orofacial pain, extravasation, myasthenia gravis, osteoarthritis and soft-tissue disorders and rheumatoid arthritis and other inflammatory disorders. Endocrine system: • Adrenal suppression during illness, trauma or surgery, serious infections in patients taking corticosteroids, osteoporosis and breast pain (mastalgia). Central Nervous System: • Psychosis and related disorders, depression, attention deficit hyperactivity disorder, obesity, nausea and vertigo, pain, epilepsy, Parkinson’s and related neuro-degenerative diseases, substance dependence, dementia. Psychiatric disorders: • Anxiety disorders, dissociative disorders, drug use and dependence, eating disorders, mood disorders, personality disorders, schizophrenia and related disorders, sexuality and factitious disorders and suicidal behaviour. 293 Paediatrics: • Various childhood diseases Respiratory: • Acute severe asthma, anaphylaxis, angiodema, chronic asthma, croup. 294 Appendix 10: The management British 295 guidelines for asthma Appendix 11: ESS normative scores Normative scores for participants who have been scored on the ESS. Scores in mild, moderate and severe Obstructive sleep apnoea syndrome. Diagnoses Total number of Pp ESS scores Range (mean ± SD) Mild OSAS 22 9.5 ± 3.3 4-16 Moderate OSAS 20 11.5 ± 4.2 5-20 Severe OSAS 13 16.0 ± 4.4 8-23 Source: Johns, M.W (1991) A New Method for Measuring Daytime Sleepiness: The Epworth Sleepiness Scale. Sleep, (14(6): 540-545. 296 Appendix 12: SF-36 normative scores and z-scores To achieve the final two scales transformed physical (PCS) and transformed mental (MCS) a series of calculations were performed. First, each SF-36 scale was standardized using z-score transformation and SF-36 scale means and standard deviations from the general UK population. A z-score for each scale is computed by subtracting the general population mean from SF-36 scale score and dividing the difference by the corresponding scale standard deviation from the general population. After a z-score has been computed for each SF-36 scale, the second step involves computation of aggregate scores for the physical and mental components using the physical and mental coefficients from the general population. The final step involves transforming each component score to the norm-based scoring. The PCS and MCS are constructed to reduce the SF-36 from a nine-scale profile to two summary measures. 297 298 299 Appendix 13: GHQ-12 normative scores What are the thresholds for GHQ? Thresholds are only relevant for screening use of the GHQ, i.e. for identifying ‘caseness’. For this use, the GHQ scoring is advocated by the test author. For GHQ30 and GHQ-60, the user will need to determine their required threshold value – we have no data on which to base a default threshold for such scoring. In general, it is best if the user specifies their required threshold value, based on past clinical use or research evidence relevant to their assessment circumstances. The following gives some threshold values that can be entered as default options. These have been derived from information in the original GHQ Manual, the User’s Guide and the following paper: Goldberg, D.P. et al (1997). The validity of two versions of the GHQ in the WHO study of mental illness in general health care. Psychological Medicine, 27, 191-197. N.B. For people who are physically ill, a higher threshold than the default one will probably be needed for optimal discrimination between cases and noncases. Suggested Default Thresholds Suggested default threshold using: GHQ GHQ Scoring Likert GHQ12 1/2 (max score 12) 11/12 (max score 36) GHQ28 4/5* (max score 28) 23/24 (max score 84) GHQ30 4/5 (max score 30) --- (max score 90) GHQ60 11/12 (max score 60) --- (max score 180) 300 Appendix 14: BDI normative scores Means and standard deviations of the BDI-II scores by sample and diagnostic groups Sample (N) Mean Std Dev Sample 22.45 12.75 12.56 9.93 26.57 12.15 28.05 11.75 29.45 11.74 Dysthymia (49) 24.02 11.86 Bipolar (34) 20.59 12.71 Depression NOS (16) 22.81 10.05 Anxiety Disorders (88) 19.38 11.46 Adjustment disorders (80) 17.29 12.33 Other disorders (68) 16.50 11.61 Outpatients (500) Sample College students (120) Diagnostic groups Mood disorders (264) Single episode, Major depression (62) Recurrent episode Major depression (103) Beck, A.T, Steer, R.A., & Brown, G.K. (1996) Beck Depression Inventory-Second edition. The Psychological Corporation, Harcourt Brace & Company. 301 Appendix 15: Phase 1 raw data 302