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ABSTRACT
Approximately 20% of all workers in industrialized countries and 15 million Americans
have work hours which overlap with the typical sleep period (United States [U.S.] Bureau of
Labor Statistics, 2007). All shift workers are at risk for shift work sleep disorder (SWSD), a type
of circadian rhythm sleep disorder (CRSD) characterized by excessive sleepiness and insomnia.
Approximately 10% of shift workers meet the diagnostic criteria for SWSD (Schwartz & Roth,
2006). Although shift work schedules and sleep insufficiency negatively affect health, safety, and
the quality of life of workers, SWSD remains an under-recognized and undertreated condition.
SWSD has serious medical, psychological, social, and quality of life consequences for
individual workers. It also affects organizations through increased health care costs, impaired job
performance, and decreased productivity (Schwartz & Roth, 2006). Fatigue in workers is a
public health concern since it has been linked to industrial accidents, medical errors, and traffic
injuries and fatalities.
The occupational and environmental health nurse (OEHN) plays a vital role in
management of SWSD in the workplace using a comprehensive, interdisciplinary approach.
Strategies such as adjusting work schedules, educating employees, families, supervisors, and
managers about SWSD and adaptive strategies, and implementing early referral and treatment to
affected workers may prevent or mitigate the negative consequences of SWSD.
Keywords: occupational health nursing, shift work sleep disorder, workplace fatigue
ii
TABLE OF CONTENTS
Page
Abstract ........................................................................................................................................... ii
Table of Contents ........................................................................................................................... iii
List of Tables .................................................................................................................................. vi
List of Figures……………………………………………………………………………….......vii
Chapters:
I.
INTRODUCTION..............................................................................................................1
Definitions............................................................................................................................1
Circadian Rhythms.........................................................................................................1
Circadian Rhythm Sleep Disorders ................................................................................2
Shift Work ......................................................................................................................3
Shift Work Sleep Disorder (SWSD) ..............................................................................5
Problems with Lack of Sleep ...............................................................................................6
Importance and Benefits of Sleep on Body Processes .........................................................9
Need for a Comprehensive Approach to Manage SWSD in the Workforce ..................... 11
Purpose of Paper ................................................................................................................ 11
II.
LITERATURE REVIEW ................................................................................................12
Incidence/Prevalence .........................................................................................................12
Risk Factors for SWSD in the Workplace .........................................................................16
Shift Schedules.............................................................................................................16
Physical Environment ..................................................................................................17
Individual Risk Factors ................................................................................................17
iii
Page
Substance Use and Abuse ............................................................................................17
Medication Use ............................................................................................................18
Comorbid Conditions ...................................................................................................18
Aging and Gender Differences ....................................................................................18
Stress, Anxiety, and Depression...................................................................................19
Consequences of SWSD ....................................................................................................19
Treatment Strategies ..........................................................................................................23
Behavioral Changes .....................................................................................................23
Medications ..................................................................................................................24
Phototherapy ................................................................................................................25
Melatonin .....................................................................................................................25
Napping ........................................................................................................................26
Barriers to Effective Management of SWSD in the Workplace ........................................26
Cost to Employers ..............................................................................................................29
III.
COMPREHENSIVE APPROACH TO SHIFT WORK SLEEP DISORDER
MANAGEMENT USING A MULTIDISICIPLINARY APPROACH ........................31
Assessment .........................................................................................................................31
Planning…………….. .......................................................................................................34
Implementation ..................................................................................................................35
Education/Training.......................................................................................................35
Incident Investigation………………………………………………………………...38
Referrals .......................................................................................................................39
iv
Page
Work Design ................................................................................................................39
Workplace Conditions ..................................................................................................40
Access to Care..............................................................................................................41
Resources .....................................................................................................................42
Evaluation… ......................................................................................................................42
Leading and Lagging Indicators ..................................................................................42
IV.
IMPLICATIONS FOR THE OCCUPATIONAL AND ENVIRONMENTAL
HEALTH NURSE ............................................................................................................44
Primary Prevention ............................................................................................................44
Secondary Prevention ........................................................................................................46
Tertiary Prevention.............................................................................................................47
V.
CONCLUSIONS/RECOMMENDATIONS ..................................................................48
Conclusions and Recommendations……………………………………………………..48
Future Research………………………………………………………………………….51
References……………………………………………………………………………….. ............53
v
LIST OF TABLES
Page
1.1
International Classification of Sleep Disorders: Categories of Circadian Rhythm
Sleep Disorders with Typical Clinical Features………………………………………….4
2.1
Adults Reporting Selected Sleep Behaviors in 12 States by Characteristics—
Behavioral Risk Factor Surveillance System, United States, 2009……………….........15
vi
LIST OF FIGURES
Page
1.1
National Sleep Foundation Sleep Duration Recommendations…………………………..7
2.1
Age-Adjusted Percentage of Adults Who Reported 30 Days of Insufficient Rest or
Sleep During the Preceding 30 Days—Behavioral Risk Factor Surveillance System,
United States, 2008…………….. ......................................................................................13
3.1
Epworth Sleepiness Scale ..................................................................................................33
3.2
Signs of Excessive Fatigue ................................................................................................37
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CHAPTER I
INTRODUCTION
With more workers engaged in irregular and non-standard working hours due to 24-hour
operations. Occupational health professionals must understand the physiological and
psychological effects of shift work, circadian disruption, and the role sleep plays in health
outcomes. This is essential to protect the health and well-being of workers.
Definitions
Sleep disorders, or somnipathies, are medical disorders of sleep patterns. The
International Classification of Sleep Disorders (ICSD-3) identifies over 80 types of sleep
disorders that affect the normal daytime wakefulness and night time sleep cycle (American
Academy of Sleep Medicine [AASM], 2014a; Office of Disability Employment Policy, 2013;
Thorpy, 2012). Commonly encountered sleep disorders in medicine and psychiatry include
insomnias, hypersomnias, sleep-related breathing disorders, parasomnias, sleep movement
disorders (e.g., restless leg syndrome, period limb movement disorder), and circadian rhythm
sleep disorders (AASM, 2014a).
Circadian Rhythms
Circadian comes from the Latin words circa meaning about and diem which means day. It
refers to bodily rhythms which vary throughout the day (American College of Emergency
Physicians [ACEP], 2014). Circadian rhythms are physiological and behavioral changes in the
body which occur on approximately a 24 hour cycle. Circadian rhythms dictate changes in
hormones levels, the body temperature cycle, appetite, and feelings of alertness. The light-dark
cycle affects circadian rhythms, and they usually work in concert with each other (Circadian
1
Sleep Disorders Network, 2014). Bodily functions such as the sleep/wake cycle, vital signs (i.e.,
temperature, heart rate, blood pressure, and respiratory rate), urinary excretion, cell division, and
hormone production all exhibit a circadian rhythm (ACEP, 2014; Harrington, 2001). Most
circadian rhythms have endogenous and exogenous components which complement each other to
support body functioning. The endogenous component is regulated by a small group of cells in
the hypothalamus of the brain called the suprachiasmatic nuclei (SCN). The exogenous
component is composed of various time clues in the environment, such as social activities,
exercise and the light/dark cycle, which are known as zeitgebers (ACEP, 2014; Whitehead,
Thomas, & Slapper, 1992).
Physiological problems can occur when the working, eating, and sleeping phases change.
For example, because heat is generated to metabolize food and use muscles during the day, the
circadian rhythm of temperature normally peaks around 4 p.m. It reaches a low at about 4 a.m.
when eating and muscle activity decline during sleep (ACEP, 2014). Experimental conditions
demonstrate that circadian rhythms remain unchanged even when environmental factors are
changed. When subjects were kept awake, in bed, and fed the same amount of calories every
hour, they still exhibited approximately the same temperature curves (ACEP, 2014). Therefore,
when individuals are forced to eat and move during typical sleeping hours, the endogenous and
exogenous factors work against each other and body temperature cycles and hormone levels related to immune function and metabolism are disturbed (ACEP, 2014).
Circadian Rhythm Sleep Disorders
The Diagnostic and Statistical Manual (DSM-5) defines circadian rhythm sleep-wake
disorders as:
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persistent or recurrent patterns of sleep disruption that is primarily due to an alteration of
the circadian system or to a misalignment between the endogenous circadian rhythm and
the sleep-wake schedule required by an individual's physical environment or social or
professional schedule. The sleep disruption leads to excessive sleepiness or insomnia, or
both. The sleep disturbance causes clinically significant distress or impairment in social,
occupational, and other important areas of functioning. (American Psychiatric
Association, 2013, p. 390)
Under extremely controlled, experimental conditions, it is possible to reverse the body’s
sleep/wake cycle, but it is difficult under ‘real life’ conditions where schedules are not strictly
controlled (Harrington, 2001). When circadian disruption or mismatch occurs, individuals usually experience an inability to fall asleep, and wake up at a desired time, and have excessive sleepiness at other times of the day (Kim, Lee, & Duffy, 2013). The symptoms disturb individuals on
a personal, occupational, and social level (Avidan, 2007). CRSDs have six subtypes, which are
described in Table 1.1. They are delayed sleep phase type, advanced sleep phase type, irregular
sleep wake type, free running type, jet lag type, and shift work type (Kim et al., 2013).
Shift Work
According to the National Sleep Foundation (NSF) (2014), the term “shift work”
generally includes any working hours other than the traditional daylight hours (i.e., 9:00 a.m. to
5:00 p.m.). Shift work includes evening, night, early morning, or rotating shifts as well as
irregular, flexible, variable, and non-standard working hours (NSF, 2014). Shift work can be
permanent, when people work regularly on only one shift, or rotating, when people alternate on
different shifts. Shift work may or may not include part or all of the night.
3
TABLE 1.1
INTERNATIONAL CLASSIFICATION OF SLEEP DISORDERS:
CATEGORIES OF CIRCADIAN RHYTHM SLEEP DISORDERS WITH
TYPICAL CLINICAL FEATURES
Disorder
Clinical Features
Delayed Sleep
Phase Type
Sleep and wake times are delayed (later) compared to normal individuals and
desired times, with striking inability to fall asleep and wake earlier at the
desired time
Advanced Sleep
Phase Type
Sleep and wake times are advanced (earlier) compared to normal individuals
and desired times, with striking inability to remain awake and remain asleep
until the desired time
Irregular SleepWake Type
Unrecognizable pattern and disorganized sleep and wake times, with
insomnia and/or excessive daytime sleepiness
Free Running
Type
Bedtimes are delayed (later) by 1-2 hours a day with insomnia and inability to
wake in the morning
Jet Lag Type
Inability to fall asleep and wake at times compatible with desired times due to
recent travel to new time zone
Shift Work Type
Inability to fall sleep (during the day) and remain awake (at night) at times
required for work schedule
Source: Kim et al., 2013
4
Shift Work Sleep Disorder (SWSD)
The diagnosis of SWSD, also referred to as shift work disorder or shift work type sleep
disorder, is comprised of the following criteria in the International Classification of Sleep
Disorders-3rd edition (ICSD-3):
1. Complaints of insomnia and/or excessive sleepiness, accompanied by a reduction of
total sleep time, which is associated with a recurring work schedule that overlaps the
usual time for sleep,
2. Symptoms that have been present and associated with the shift work schedule for at
least 3 months,
3. Sleep log and actigraphical (i.e., sleep movement) monitoring (whenever possible and
preferably with concurrent light exposure measurement) for at least 14 days (work
and free days) that demonstrates a disturbed sleep and wake pattern, and
4. Sleep and/or wake disturbance that is not explained by another sleep disorder, a
medical or neurological disorder, mental disorder, medication use, poor sleep hygiene,
or substance use disorder.
(Berry & Wagner, 2015, p. 647)
The two major symptoms of SWSD, insomnia and excessive sleepiness, must be
associated with a work shift which occurs during the hours that are usual sleep times, such as
night, or early morning hours (Drake, Roehrs, Richardson, Walsh, & Roth, 2004). In most cases,
sleep time is reduced by approximately one to four hours, and sleep quality is described as
unsatisfactory. The individual usually experiences difficulties with sleep initiation and
awakening, and diminished alertness which impairs mental ability and work performance
(Schwartz & Roth, 2008). The distinction between a ‘normal’ and an ‘abnormal’ response to shift
5
work is not definitive and SWSD is differentiated from simply poor adaptation to shift work by
clinically significant, persistent sleepiness and insomnia (Culpepper, 2010). Sleep studies, sleep
logs, and actigraphical monitoring criteria are used to make the diagnosis (AASM, 2014a).
The symptoms of SWSD generally interfere with work and family life, and overall health
and quality of life. According to the AASM (2014b), many workers may have difficulty adjusting
to a new shift, and it may be difficult to determine a normal versus a pathological response to the
circadian misalignment of the sleep-wake schedule. More recent data suggest that workers who
appear to be adapting well to shift work may have unrecognized physiological issues (Neurology
MedLink, 2014).
Problems with Lack of Sleep
The recommended level of sleep differs across the age spectrum (Figure 1.1), with a
gradual decrease in the hours of sleep needed as one ages. Chronic lack of sleep is associated
with conditions such as high blood pressure, heart disease, diabetes, several types of cancer, and
even shortened life expectancy (Culpepper, 2010). Three large, cross-sectional epidemiological
studies revealed an approximately 15% increase in mortality from all causes among those who
slept five hours or less per night (Division of Sleep Medicine at Harvard Medical School,
2007a).
According to Strine and Chapman (2005), individuals who reported sleep insufficiency
were also more likely to smoke, be sedentary, obese and, among men, abuse alcohol. When
health-related quality of life (HRQOL) was assessed, respondents who reported obtaining
insufficient sleep on a frequent basis (not enough sleep on 14 days or more over the past 30 days)
were significantly more likely to report “poor general health, frequent physical distress, frequent
6
FIGURE 1.1
Source: NSF, 2015b
7
mental distress, activity limitations, depressive symptoms, and anxiety, and pain” (Strine &
Chapman, 2005, p. 23).
Chronic sleep issues have also been associated with mood disorders such as depression,
anxiety and mental distress (Division of Sleep Medicine at Harvard Medical School, 2007a).
Studies have shown that individuals who were able to sleep only four to four and one-half hours
per night reported feeling more stressed, sad, angry, mentally exhausted, and showed declining
levels of optimism and sociability (Division of Sleep Medicine at Harvard Medical School,
2007a). Lack of sleep and sleep disorders may result in family disruption by impairing family
cohesiveness and even lead to marital issues and divorce (Institute of Medicine [IOM], 2006).
Poor sleep quality may affect an individual’s capacity to care for children or ill family members
as well.
The exact economic impact of poor sleep is not known, but it is estimated that tens of
billions of dollars are spent annually on medications and medical care due to sleep problems
(IOM, 2006). According to two large studies (Åkerstedt,, Fredlund, Gillberg, & Janson, 2002;
Swaen, Van Amelsvoort, Bultmann, & Kant, 2003), after adjusting for other risk factors, highly
fatigued workers were 70% more likely to be involved in accidents than were workers reporting
low fatigue levels. In addition, workers reporting disturbed sleep were nearly twice as likely to
die in work-related accidents (Åkerstedt, Fredlund et al., 2002).
Drowsy driving is responsible for 20% of all motor vehicle accidents annually in the
U.S., which amounts to approximately 1 million crashes, 500,000 injuries, and 8,000 deaths each
year (National Highway Traffic Safety Administration, 2011). According to a NSF (2015b)
survey, one-third of all adult drivers say they have fallen asleep at the wheel. Wakefulness for 24
hours impairs behavioral performance comparable to having a blood alcohol level of 0.10% (the
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legal limit for driving is 0.08% in the U.S.) (National Institute for Occupational Safety and
Health [NIOSH], 2015; Dawson & Reid, 1997).
The public health effects of fatigue and sleep loss have been demonstrated by environmental disasters such as the oil spill of the Exxon Valdez tanker and the chemical plant disaster
in Bhopal, India. Fatigue and shift work were found to be contributing factors to incidents such
as the Three Mile Island nuclear power station release in 1979, Challenger Space Shuttle rocket
explosion in 1986, Chernobyl nuclear power station release in 1986, Clapham Junction rail crash
in 1988, and Buncefield oil refinery explosion in 2005 (Health and Safety Authority, 2012). Relationships between medical errors, sleep loss, and extended hours of work by doctors and nurses
have also been well documented (IOM, 1999). The Division of Sleep Medicine at Harvard Medical School (2007c) reported that hospitals could reduce the number of medical errors by as much
as 36% by limiting an individual doctor’s work shifts to 16 hours and reducing work hours to no
more than 80 per week (Lockley et al., 2007). Despite the numerous physical and mental health
problems, accidents, injuries, mortality, and loss of productivity associated with it, chronic sleep
insufficiency is still an under addressed public health issue. Insufficient sleep, unlike other health
risk factors such as smoking, excessive alcohol consumption, obesity, and physical inactivity,
has historically received much less attention in both the public health and clinical settings (Perry,
Patil, & Presley-Cantrell, 2013).
Importance and Benefits of Sleep on Body Processes
Sleep is vital to many body processes such as memory and learning, metabolism, immune
function, and cardiovascular responses. It is an opportunity for the body to repair and rejuvenate
itself (Division of Sleep Medicine at Harvard Medical School, 2007d). Sleep is thought to be
correlated with changes in the structure and organization of the brain, a phenomenon, known as
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brain plasticity (Division of Sleep Medicine at Harvard Medical School, 2007d). The quantity
and quality of sleep has an impact on learning and memory in two distinct ways. First, adequate
sleep allows an individual to focus attention optimally and learn efficiently. Second, sleep plays a
role in the acquisition and stabilization of memories, which is essential for learning new
information (Marquie, Tucker, Folkard, Gentil, & Ansiau, 2014). Sleep and rest enable neurons
to coordinate information properly so that previously learned information may be accessed.
Alertness, and sound decision making capability (i.e., judgment) are dependent on adequate sleep
(Division of Sleep Medicine at Harvard Medical School, 2007b).
Many restorative body functions such as muscle growth, tissue repair, protein synthesis,
and growth hormone release occur mostly or entirely during sleep (Division of Sleep Medicine at
Harvard Medical School, 2007d). Sleep decreases cortisol levels, which, if elevated, lead to the
development of insulin resistance, a risk factor for obesity and type two diabetes (Spiegel,
Leproult, & Van Cauter, 1999).
Sleep and the circadian system also regulate immunological processes. Sleep deprivation
and the accompanying stress response may lead to pro-inflammatory cytokines, or chronic lowgrade inflammation, and immunodeficiency (Besedovsky, Lange, & Born, 2012).
The cardiovascular system is depressed during the deep sleep stages, also known as nonREM (rapid eye movement) sleep. During deep sleep, the heart rate and blood pressure decrease,
respiratory rate slows and the core body temperature drops. Inadequate sleep in people who have
existing hypertension can cause elevated blood pressure throughout the following day which may
explain the correlation between poor sleep and cardiovascular disease and stroke (Division of
Sleep Medicine at Harvard Medical School, 2007a).
10
Need for a Comprehensive Approach to Manage SWSD in the Workforce
Worker fatigue and excessive sleepiness, which are characteristics of SWSD, can
negatively affect individual health and quality of life as well organizational safety and
productivity. According to the American College of Occupational and Environmental Medicine
(ACOEM), a comprehensive approach to manage fatigue in the workplace requires active
participation at all levels of an organization (ACOEM, 2012). The OEHN should be instrumental
in developing and implementing an approach to manage SWSD in the workplace, and coordinate
efforts with other members of the occupational health team, human resources, as well as workers
and their families.
Purpose of Paper
The purpose of this paper is to describe SWSD and its impact on workers and
organizations. Interdisciplinary management strategies will be reviewed with emphasis on
opportunities for the OEHN to prevent and mitigate its negative consequences.
11
CHAPTER II
LITERATURE REVIEW
Incidence/Prevalence
Approximately 40 million Americans are diagnosed with a chronic long-term sleep
disorder each year. Twenty million people have occasional sleep problems (National Institute of
Neurological Disorders and Stroke, 2014). The major causes of sleep loss include lifestyle and
occupational factors and specific sleep disorders. The CDC analyzed data in the Behavioral Risk
Factor Surveillance System (BRFSS) in 2009 and found from the 74,571 adult respondents in 12
states (California, Georgia, Hawaii, Illinois, Kansas, Louisiana, Maryland, Minnesota, Nebraska,
New York, Texas, and Wyoming):

35.3% reported having < 7 hours of sleep on average during a 24-hour period,

48.0% reported snoring,

37.9% reported unintentionally falling asleep during the day at least 1 day in the
preceding 30 days, and

4.7% reported nodding off or falling asleep while driving in the preceding 30 days.
(CDC, 2011, p. 233)
The distribution of reported days of insufficient rest or sleep varies among states and
territories (Figure 2.1). The lowest age-standardized prevalences of 30 days of insufficient rest or
sleep in the preceding 30 days were observed in North Dakota (7.4%), California (8.0%), District
of Columbia (8.5%), Wisconsin (8.6%), and Oregon (8.8%); the highest were observed in Puerto
Rico (14.0%), Oklahoma (14.3%), Kentucky (14.4%), Tennessee (14.8%), and West Virginia
(19.3%). CDC (2009) concluded that further studies are needed to explain gender and
12
FIGURE 2.1
AGE-ADJUSTED* PERCENTAGE OF ADULTS WHO REPORTED 30 DAYS
OF INSUFFICIENT REST OR SLEEP† DURING THE PRECEDING 30 DAYS—
BEHAVIORAL RISK FACTOR SURVEILLANCE SYSTEM, UNITED STATES,§ 2008
Source: CDC, 2009
* Age adjusted to 2000 projected U.S. population.
† Determined by response to the question, "During the past 30 days, for about how many days
have you felt you did not get enough rest or sleep?"
§ Includes the 50 states, District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands.
13
racial/ethnic differences apparent in these results. Women are underrepresented in studies of
sleep and sleep disorders, and racial and more ethnic minorities report sleep durations that are
associated with increased mortality (CDC, 2009).
When selected sleep behaviors were analyzed (Table 2.1), adults aged 18-24 years
(43.7%) and ≥65 years (44.6%) were significantly more likely to report unintentionally falling
asleep during the day at least once in the past month than all other age groups, as were persons
from all other racial/ethnic categories compared with non-Hispanic whites (33.4%). No
significant difference was observed by sex. Persons aged ≥65 years (2.0%) were significantly
less likely to report nodding off or falling asleep while driving in the preceding 30 days than
persons aged 25-34 years (7.2%), 35-44 years (5.7%), 18-24 years (4.5%), 45-54 years (3.9%),
and 55-64 years (3.1%). Hispanics (6.3%), non-Hispanic blacks (6.5%), and non-Hispanics of
other races (7.2%) all were significantly more likely to report this behavior than non-Hispanic
whites (3.2%). Men were more likely (5.8%) to report this behavior, compared with women
(3.5%) (CDC, 2009).
Typical occupations which involve shift work include law enforcement officers,
firefighters, military members, health care workers, retail clerks, convenient store employees,
restaurant staff, truckers, airline pilots, flight attendants, and others in industries which require 24
hour operation. In general, working people sleep less than those not employed, and 38% of all
working people consider themselves fatigued (CDC, 2009). Those who have multiple jobs sleep
less than those with only one job. Sleep duration also tends to be shorter on workdays compared
to non-working days (Rosa, 2005).
14
TABLE 2.1
Source: CDC, 2009
15
Approximately 20% of the U.S. workforce is employed in shift work, and 25-30% of
shift workers experience symptoms of excessive sleepiness or insomnia (Beers, 2000), and 5%
to 10% of those experience sleep-wake disturbances severe enough to be diagnosed (per the
ICSD) as SWSD (Drake et al., 2004). The exact prevalence of SWSD by shift worked is
unknown, but according to a study by Drake et al. (2004), which combined formal diagnostic
criteria with an epidemiologic sample (using questionnaire data and not clinical evaluation),
32.1% of night workers and 26.1% of rotating workers met the minimum criteria for SWSD
(Sack et al., 2007). In some cases, the symptoms of SWSD often persist even after shift work is
stopped (Åkerstedt & Wright, 2009).
Risk Factors for SWSD in the Workplace
Every shift worker may be considered at risk for SWSD. Factors which predispose a
worker to poor adaptation to shift work in general may also increase the likelihood of SWSD.
Shift Schedules
Scheduling which requires early morning start times, late evening shifts, split shifts, or
shifts over 12 hours in length puts workers at risk for circadian misalignment (ACOEM, 2012).
Shift rotation patterns and durations which are not ideal, and insufficient rest breaks within and
between shifts can negatively affect adaptation to shift work. Overtime and extended (e.g.,
beyond 8 hours) work shifts with inadequate time off due to ‘self-scheduling,’ ‘swapping,’ or
trading hours, as well as ‘on call’ work hours may affect the ability to obtain the needed amount
of sleep. Erratic shift patterns, reverse rotation (e.g., rotating from nights to days), and length of
rotation (either too fast or permanent night) may interfere with achieving sufficient sleep.
Clockwise shift rotation is preferred, since it follows the natural adaptive pattern of the sleep
period. When a worker on a permanent night shift attempts to stay awake during the day and
16
sleep at night during days not working, it is less likely full adaptation will be possible. Shift
rotation every 2 days is tolerated better than every 7 to 14 days, and longer rotations of a month
or more allow for better accommodation (Rogers, Randolph, & Mastroianni, 2009).
Physical Environment
The physical environment of the work facility, such as temperatures which are not
comfortable as the body temperature drops, inadequate lighting, poor ventilation, no areas for
workers to rest and lack of canteens or cafeterias on-site with healthy food options put the
worker at higher risk for decreased adaptation to shift work. Shift workers also may also have
less tolerance to chemicals used in the workplace because circadian rhythm changes make the
body more sensitive to toxins at certain times of day (NIOSH, 1997).
Individual Risk Factors
Individual risk factors for SWSD include preexisting sleep disorders, such as obstructive
apnea disease, or restless leg syndrome (RLS). Sleep disorders are often overlooked by health
care providers as demonstrated in a study of health care screening clinics. Only 43% included
sleep-related questions on their screening batteries compared with 100% for smoking and
alcohol, 93% for healthy eating, and 86% for physical activity (Perry et al., 2013).
Substance Use and Abuse
Sleep disturbances have been associated with drug use, drug abuse, and withdrawal from
drug abuse (Division of Sleep Medicine at Harvard Medical School, 2007a). Alcohol has been
linked to sleep disturbances since it is used as a mild sedative by people with insomnia. The
sedative quality of alcohol is only temporary, and as it is processed, it may cause arousal and
result in wakefulness (Division of Sleep Medicine at Harvard Medical School, 2007a). Illegal or
17
illicit drugs such as marijuana (legality varies by state), heroin, cocaine, amphetamines, and
methamphetamines, may also interfere with sleep quality and duration (Cleveland Clinic, 2013).
Medication Use
Side effects of medications, especially those which cause restlessness or somnolence,
may interfere with sleep timing and duration as well. Prescription drugs such as, blood pressure
medication, hormones and oral contraceptives, steroids (including prednisone), respiratory
medications, diet pills, attention deficit medications, and some antidepressants may impair sleep.
Common non-prescription drugs or substances like pseudoephedrine, nicotine, and caffeine may
also cause sleep issues (Cleveland Clinic, 2013).
Comorbid Conditions
Comorbid conditions may independently cause insomnia or sleepiness or contribute to it.
Conditions such as heart disease, diabetes, cancer, or treatments for these conditions may
compound fatigue and predispose the worker to SWSD (Rajaratnam, Howard, & Grunstein,
2013). Other conditions known to impair sleep quality or quantity include RLS, acid reflux,
irritable bowel syndrome, gastric ulcer disease, musculoskeletal disorders, arthritis, dental and
orofacial pain, spinal cord damage, burns, overactive bladder and depression (IOM, 2006).
Aging and Gender Differences
Sleep regulation can become a problem for the older worker since sleep studies show that
sleep becomes more fragmented (i.e., waking up during the night) with aging (Harrington, 2001).
According to Blok and de Looze (2011), there is no conclusive evidence that older workers
tolerate shift work less effectively than younger workers, and more research is needed in this
area. Women have been documented to tolerate shift work less successfully than males, which
18
may be related to greater domestic obligations and to the tendency for women to report health
symptoms more often than men (Harrington, 2001).
Stress, Anxiety, and Depression
Stress, anxiety, and depression have been found to have a detrimental effect on the ability
to fall asleep or maintain a sleep state. Stress caused by family responsibilities, such as child or
elder care, or other commitments may put the worker at increased risk for SWSD due to
sacrificing sleep to fulfill obligations. Results of a cross sectional study in Sweden by Åkerstedt,
Knutsson et al. (2002) indicated that that work stress variables such as high work demands, low
social support at work and physically demanding work are associated with sleep disturbances.
Depression is one of the most common comorbidities with insomnia (IOM, 2006). According to
Breslau, Roth, Rosenthal, & Andreski (1996), insomnia is a significant predictor of subsequent
depression.
Consequences of SWSD
Shift workers not only struggle with excessive sleepiness during the hours when they
work, but also with family and friends during leisure time activities (NSF, 2015b). Excessive
sleepiness can be constant, which interferes with the ability to work, concentrate, or engage in
social activities. Individuals may sometimes experience “micro sleeps,” which are brief, involuntary occurrences of falling asleep. A micro sleep usually lasts a few seconds but can be extremely
dangerous or even fatal depending on the circumstances (National Highway Traffic Safety Administration, 2011; NSF, 2015a; NSF, 2015c). Exposure to shift work, especially rotating shift
work of more than 10 years duration, was found to have a highly significant association with
chronic impairment of cognition, with recovery taking at least five years after stopping shift
work (Marquie et al., 2014).
19
Gastrointestinal issues are also associated with shift work. Indigestion, nausea, diarrhea,
constipation, heartburn, and loss of appetite are more common among shift workers and night
workers than among day workers. More serious conditions such as peptic ulcers are also higher
in the shift worker population (Knutsson, 2003).
Several large epidemiological studies (Ayas et al., 2003; Bradley et al., 2005; Caples,
Gami, & Somers, 2005; Eaker, Pinsky, & Castelli, 1992; Newman et al., 2000; Qureshi, Giles,
Croft, & Bliwise, 1997; Schwartz et al., 1998) have associated sleep loss and sleep complaints
with myocardial infarction and stroke. Several mechanisms may explain the link between sleep
impairment and cardiovascular events, such as blood pressure increases, sympathetic
hyperactivity, or impaired glucose tolerance (Division of Sleep Medicine at Harvard Medical
School, 2007a). Medications used to treat cardiovascular disease have also been associated with
sleep impairment. Beta-antagonists (i.e., beta-blockers) are associated with fatigue, insomnia,
nightmares, and vivid dreams (McAinsh & Cruickshank, 1990). The mechanism underlying
sleep disruption by beta-blocking agents may be their tendency to deplete melatonin, an
important sleep-related hormone (Dawson & Encel, 1993; Garrick, Tamarkin, Taylor, Markey, &
Murphy, 1983). Fatigue and somnolence have also been reported with other antihypertensive
medications such as labetalol, clonidine, methyldopa, and reserpine (Miyazaki, Uchida, Mukai,
& Nishihara, 2004; Paykel, Fleminger, & Watson, 1982). In contrast, angiotensin-converting
enzyme inhibitors (i.e., enalapril, lisinopril) have few effects on sleep (Reid, 1996). Some lipid
lowering drugs have been associated with reports of insomnia, but placebo-controlled clinical
trials of lovastatin, simvastatin, and pravastatin did not appear to increase sleep disturbances
(Bradford et al., 1991; Keech et al., 1996). Amiodarone, a widely use antiarrhythmic agent can
cause nocturnal sleep disturbances (Hilleman, Miller, Parker, Doering, & Pieper, 1998), and
20
digoxin has been associated with both insomnia and daytime fatigue (Weisberg et al., 2002).
Insufficient sleep can also modify the effectiveness of certain drugs, and as a result aggravate
underlying conditions. Sleep deprivation can make some medications used to treat epilepsy less
effective (IOM, 2006).
Life style factors among fatigued individuals, such as poor food choices and decreased
physical activity, often contribute to increases in obesity, dyslipidemia, and insulin resistance
along with related cardiovascular changes due to circadian misalignment (Karlsson, Alfredsson,
Knutsson, Andersson, & Toren, 2005).
Insufficient sleep may lead to type 2 diabetes by influencing the way the body processes
glucose. One short-term sleep restriction study found that a group of healthy subjects who
decreased sleep time from eight to four hours per night processed glucose more slowly (Spiegel
et al., 1999). The Sleep Heart Health Study (Gottlieb et al., 2005) revealed that adults who
usually slept less than five hours per night were 2.5 times more likely to have diabetes compared
to those who reported sleeping seven to eight hours per night (IOM, 2006).
Shift work, particularly night work, may present risks to women of child bearing age,
since the circadian clock is involved in regulation of nearly every part of the reproductive cycle
(Gamble, Resuehr, & Johnson, 2013). Shift work has been associated with an increased risk of
irregular menstrual cycles, endometriosis, infertility, miscarriage, low birth weight, or pre-term
delivery, and reduced incidence of breastfeeding (Culpepper, 2010). The causative factors may
include disruption of the menstrual cycle and increased stress from the conflicts created by night
work (Gamble et al., 2013).
The International Agency for Research on Cancer (IARC) expert working group
concluded in 2008 that shift work is a “probable carcinogen” due to the circadian disruption and
21
the effect of light at night (IARC, 2010). Previous studies have documented night-shift work to
be associated with an increased risk of breast cancer (Megdal, Kroenke, Laden, Pukkala, &
Schernhammer, 2005), endometrial cancer (Viswanathan, Hankinson, & Schernhammer, 2007)
and colorectal cancer (Schernhammer, Laden, & Speizer, 2003). Job histories, including work
hours from men who had worked at night, were compared to men who had not worked at night.
The adjusted odds ratios among men who had worked at night were significantly higher for lung,
colon, bladder, prostate, rectal, and pancreatic cancer, and non-Hodgkin’s lymphoma (Parent, ElZein, Rousseau, Pintos, & Siemiatycki, 2012).
Chronic sleep issues have been correlated with depression, anxiety, and mental distress.
Feeling more stressed, sad, angry, and mentally exhausted have all been associated with less
hours of sleep (Division of Sleep Medicine at Harvard Medical School, 2007a). In one study,
subjects who slept four hours per night showed declining levels of optimism and sociability as
the days of reduced sleep increased. All of these self-reported symptoms improved dramatically
when subjects returned to a normal sleep schedule (Division of Sleep Medicine at Harvard
Medical School, 2007a). A recent U.S. study of police found that anxiety and depression were
more than twice as common in those who had impaired sleep (Rajaratnam, Barger, & Lockley,
2011). Individuals diagnosed with SWSD experienced a higher rate of sleepiness-related
accidents, absenteeism, depression, reduced social and family activities than shift workers
without the diagnosis (Drake et al., 2004).
Many workers feel social isolation while working atypical shifts. Work schedules may
infringe upon an individual’s ability to sleep, eat normally, exercise, and develop relationships.
Family and marital responsibilities can be severely disrupted by shift work or long hours. Issues
related to childcare, housework, shopping, and leaving a partner alone at night can all lead to
22
marital strain and family dysfunction. Permanent night shift workers with SWSD missed 8.6
days of family or social activity per month versus 1.5 days in those without SWSD; rotating-shift
workers with SWSD missed 10.1 days of family or social activity each month versus 1.0 day in
their colleagues without SWSD (Drake et al., 2004). Ten percent of shift workers complain about
issues related to shift work during their working life. Twenty percent of all shift workers stop
shift work because of serious health problems, and the remaining 70% continue shift work with
issues or diseases which become more evident and/or severe at different times (Waterhouse,
Folkard, & Minors, 1992).
Treatment Strategies
Treatments recommended as part of the Practice Parameters for the Evaluation and
Treatment of Circadian Rhythm Sleep Disorders from the AASM (2007) have been evaluated in
shift workers generally, rather than specifically, in those with SWSD. According to Thorpy
(2010), the delineation between workers who have issues with sleep during shift-work conditions
and individuals who develop SWSD is not clear, and literature specific to SWSD will remains
sparse.
Behavioral Changes
Psychological treatments such as cognitive behavioral therapy (CBT) have proven
effective in managing insomnia (Buysse, 2013). Behavior changes such as maintaining regular
sleep-wake times, avoiding unplanned naps, engaging in a regular routine of exercise, and
avoiding caffeine, nicotine, and stimulating activities within several hours of bedtime have also
been beneficial treating circadian rhythm disorders. Individuals who kept the same sleep routine
and schedule on work days as well as days off were found to have better outcomes than those
who did not (ACOEM, 2012).
23
Limiting exposure to bright light and sunlight directly before or while attempting to sleep
with the use of black-out curtains and light-blocking goggles or glasses, are effective measures
since the circadian cycle is stimulated by sunlight. Noise reduction in the home environment
(e.g., deactivating door bells, keeping pets and children quiet, posting signs for delivery persons
and visitors, requesting that neighbors mow lawns at non-sleeping hours, etc.) or noise blocking
measures such as the use of earplugs are also important (ACOEM, 2012).
Medications
Sleep-inducing prescription drugs (such as zolplidem and eszoplicone) have shown some
success in use on a short-term basis (Vijay & Bromley, 1999). Sedative-hypnotics should be used
carefully due to their potential side effects, including the carry-over of sedation to the night shift,
which may negatively affect performance and safety (Monchesky, Billings, Phillips, &
Bourgouin, 1989). Use of over-the-counter stimulants and caffeine may help alertness if used at
the proper dose and the appropriate time. Based on evidence from large, controlled clinical trials,
wakefulness-promoting agents, such as modafinil and armodafinil, improve alertness without
many of the adverse effects of stimulants, and have the potential of managing excessive
sleepiness during shift work (Czeisler, Walsh, & Roth, 2005). These agents are approved by the
U.S. Food and Drug Administration (FDA) for the treatment of excessive sleepiness in workers
with shift work disorder (Rajaratnam et al., 2013). Pharmacological treatment is only aimed at
managing excessive sleepiness in shift workers. There is no evidence that these agents facilitate
circadian adaptation to a shift schedule or promote sleep (Rajaratnam et al., 2013). Though
alcohol before bedtime promotes sleep onset, alcohol tends to shorten total sleep time (Vijay &
Bromley, 1999). The use of cannabis and non-medically prescribed drugs to manage sleep
complaints could potentially make sleep issues worse and should be avoided.
24
Phototherapy
To help the circadian rhythm adapt to shift work, bright light treatment (phototherapy)
during night shift work suppresses melatonin release and increases body temperature and cortisol
levels, whereas the use of light-blocking goggles or glasses in the morning after night shift work
would generate the opposite effects. Phototherapy involves a light box to deliver light
approximately five times brighter than normal indoor light (Vijay & Bromley, 1999). Bright light
therapy may be used to either advance or delay sleep. The duration of exposure varies from one
to two hours, and the timing of the treatment is critical and requires guidance from a sleep
specialist (Boivin & James, 2005). The adjustment process takes several days, and for workers
who rotate shifts on a weekly basis, phototherapy alone will be insufficient to alleviate their
issues (Boivin & James, 2005). Shift workers who switch to a ‘normal,’ night-sleep, day-wake
schedule on days off will most likely never fully adapt to a night work schedule (Canadian
Center for Occupational Health and Safety, 2014).
Melatonin
Melatonin is a hormone produced by the pineal gland as part of the circadian rhythm.
During the night, higher levels of melatonin are released than during the daytime which causes
sleepiness. Melatonin can be produced synthetically and obtained over-the-counter. It is
primarily used to treat jet lag type sleep disorders but could also be used to promote sleep during
the daytime in shift workers (Rajaratnam, Cohen, & Rogers, 2009). Although melatonin is safe
for short-term use, long-term safety data are lacking (Rajaratnam et al., 2013) and its effects on
total sleep time are not clear. Potential adverse effects of melatonin include disturbed sleep, and
the inhibition of ovulation by decreasing the levels of luteinizing hormone concentrations in the
blood (Vijay & Bromley, 1999).
25
Napping
Scheduled napping for shift workers may be useful in relieving excessive sleepiness
during work shifts and can maintain or improve subsequent performance and physiological
alertness from 2 to 12 hours following the nap (Barger, Lockley, Rajaratnam, & Landrigan,
2009). Naps ranging from 20 to 40 minutes taken during the work shift have been shown to be
effective at increasing alertness (Barger et al., 2009; Ruggiero & Redeker, 2014). However, the
exact recommendations for naps on duty have not been clarified.
Barriers to Effective Management of SWSD in the Workplace
Businesses view shift work as a means to increase productivity by reducing or
eliminating start-up times in manufacturing lines, and accommodating consumer market demand
for 24 hour services (Bird, 2007). In most organizations, production demands, work tasks, work
load demands, and skill of the work force dictate shift designs and scheduling practices, and
there is little regard for the impact various shift rotations may have on employee health and
safety. In 24 hour industries such as health care or law enforcement, shift work is unavoidable.
Another barrier to effective management of SWSD in the workplace is the need for
further integration of workplace programs which address both worker health and workplace
safety. In 2011 NIOSH launched the Total Worker Health (TWH) Program. This program was
developed to integrate occupational safety with health protection and health promotion to prevent
worker injury and illness and to advance worker health and well-being (NIOSH, 2012). The
program supports research efforts and the adoption of best practices of integrative approaches
that would address health risks (such as shift work) from both the work environment (physical
and organizational) and individual behavior (NIOSH, 2012). SWSD requires organizations to
address workplace issues such as extended hours of work and work schedules which are not
26
conducive to proper sleep habits, as well as worker health and well-being issues.
Suboptimal scheduling practices such as rotating shifts in a non-clockwise manner, and
abrupt and frequent rotational changes are often barriers to workers being able to adjust their
sleep schedules. One important finding about the internal "clock" is that subjects who are
isolated and removed from all zeitgebers will go to bed an hour later each "day" and sleep an
hour longer into the next day. It is thought that this allows for external adjustment depending on
the season and other environmental considerations. This is the basis for recommending a
clockwise shift rotation which takes advantage of the natural tendency to stay up progressively
later (ACEP, 2014).
The work environment may lack adequate lighting, break or rest areas, or nutritious food
items for shift workers. Without proper nutrition, the ability to cope with the increased stress of
shift work will be impaired (Health and Safety Authority, 2012). Choices of food and mealtimes
also play a role in obtaining adequate sleep. Organizational factors, such as lack of hot, fresh
food, dining areas, and break times allotted for meals or snacks will have a negative effect on
proper nutrition. Meal times are seldom prioritized during atypical work hours, and may be
overlooked due to decreased staffing levels.
Supervisors and managers may be either absent during shift work or lack knowledge
about SWSD and its signs and symptoms, and how it may affect workers. There may also be a
knowledge deficit regarding the hazards of impaired or inadequate sleep, and the view that
SWSD is a performance issue versus a physiological impairment (Moore-Ede, 2009).
Health promotion programs which focus on disease prevention and healthy behaviors
often lack strategies which adequately address the unique needs of shift workers (Richter, Acker,
Scholz, & Niklewski, 2010). According to Aguirre and Moore-Ede (2008), 90% of shift workers
27
receive no training on how to manage their schedules and shiftwork lifestyles. Resources may
sometimes not be sufficient to allow for health promotion programs and events, such as wellness
fairs, screenings, and health coaching to be conducted on all shifts.
Workers who commute long distances, or choose to delay or interrupt sleep due to family
obligations such as ‘daycare,’ are at high risk for issues associated with SWSD. In addition,
home sleeping conditions, such as room temperature, and noise and light level of the bedroom,
may impair sleep. Dietary patterns such as consuming large meals, caffeine, or alcohol before
sleep can have a negative effect on sleep quality and duration. Meal times should be scheduled so
that the main meal of the day is eaten during or before the work period. Exercise has been shown
to be helpful in promoting sleep onset and improving the perceived quality of sleep, but many
workers forgo exercise due to fatigue (Occupational Health Clinics for Ontario Workers, 2005).
Economic issues such as not being able to afford child care or having a second job
impede the worker’s ability to address or manage sleep disorders effectively. Many workers
continue working nontraditional hours because organizations offer financial incentives and pay
differentials for shift work. Workers may feel they cannot “afford” to switch to traditional hours.
Lack of worker and family education regarding the signs and symptoms of SWSD, when to seek
treatment, and treatment strategies are also barriers to effective management (Moore-Ede, 2009).
Non-traditional shift workers are also often paid higher wages and working overtime is rewarded
with bonuses. These practices act as incentives for workers who may not be aware of the hazards
associated with shift work and insufficient sleep.
Organizational issues such as inadequate staffing levels due to leaves, illnesses, or increased production needs and policies which require extended work shifts (i.e., longer than 8
hours) should be addressed. Extended hours work and mandatory overtime often include non28
traditional hours and may further exacerbate fatigue issues due to inadequate sleep and recovery
time between shifts (ACOEM, 2012). Sixty-nine percent of facilities which required extended
hours shift work reported moderate or severe fatigue problems among their workers (Sloan Work
and Family Research Network, 2010). More flexibility in employee scheduling is associated with
lower turnover and absenteeism rates, and mandatory overtime has been associated with the
highest turnover rates (Aguirre & Moore–Ede, 2008).
Cost to Employers
A recent meta-analysis (Uehli et al., 2014) quantified the association between sleep
problems and injuries. Sleep disorders, poor sleep quality and quantity, daytime sleepiness, and
sleep medication increased the incidence of injuries by a factor of 1.62. Approximately 13% of
work injuries were due to sleep problems (Uehli et al., 2014). Fatigued workers cost employers
$136.4 billion annually in health-related lost productive time, almost four times more than nonfatigued workers. In 2009, the combined cost of road and workplace accidents caused by
excessive sleepiness was estimated to be 71 to 93 billion dollars a year in the U.S., with shift
work being a major contributor (Rajaratnam et al., 2013).
High absenteeism rates require increases in staffing levels to cover shifts and vacant
positions. This also sets up a cycle between overtime and fatigue. As overtime increases, the
fatigue levels rise among workers and the likelihood of fatigue-related accidents increase
(Circadian 24/7 Workplace Solutions, 2014). According to Kleinman, Brook, Doan, Melkonian
and Baran (2009), the estimated annual cost of insomnia in the U.S. civilian workforce was
estimated to be about 15.0 to 17.7 billion dollars. In 2002 it was estimated that 27 million
prescriptions or $1.2 billion worth were filled for hypnotics (Mendelson, 2005).
29
Shift work and associated issues also have an effect on employee satisfaction and
retention which costs organizations approximately 21% of their non-exempt payroll (Martin,
Sinclair, Lelchook, Wittmer, & Charles, 2012). As Martin et al. (2012) concluded,
More attention to the processes managers use to assign schedules may help increase
retention length and attain other desirable outcomes, such as improved job performance,
positive citizenship behaviors, and employee health and well-being. These possibilities
highlight the need for return-on-investment studies of retention strategies, particularly
with respect to managing undesirable work schedules. (p. 18)
30
CHAPTER III
COMPREHENSIVE APPROACH TO SHIFT WORK SLEEP DISORDER
MANAGEMENT USING A MULTIDISICIPLINARY APPROACH
A systematic approach to manage SWSD requires a thorough assessment of the issues
specific to the shift worker population involved and careful planning and implementation of
evidence-based interventions to address these issues. Evaluation should begin in the planning
stage, and continue throughout implementation to ensure quality improvement.
Assessment
Sleeping, waking issues, and fatigue are highly probable in all shift workers at some point
(Rajaratnam et al., 2013), making it prudent for all organizations to adopt policies and processes
to address these issues. An assessment should be conducted to identify any adverse effects
associated with a particular shift pattern.
Occupational and environmental safety and health (OESH) team members, human
resources personnel, managers, and supervisors must collaborate to assess issues which
contribute to maladaptation of shift workers. Input from senior level management, human
resources, safety colleagues, and most importantly workers should be sought as part of the
assessment phase to determine needs and issues. Scheduling practices, facility layout, job tasks,
and employee incidents and injuries are important factors to consider.
A walk-through conducted during ‘off’ shifts with members of the OESH team is a
valuable opportunity to obtain employee input as well as identify factors that are pertinent to
shift worker health and safety. Interdisciplinary input from safety specialists, industrial
hygienists, EAP personnel, ergonomic specialists, occupational medicine, health promotion, and
31
occupational health nursing professionals provides a comprehensive view of on-going issues.
Workplace barriers which could impede employee health and safety may include inaccessibility
to healthy food and rest areas, inadequate security in isolated areas of a facility, lack of protocols
for checking on lone or isolated workers, monotonous work tasks with little stimulation or
variety, and poor air quality, lighting, and temperature control of the work areas. Assessments of
work processes and the work environment on non-traditional shifts may reveal needed
interventions to manage SWSD and fatigue in the workplace (ACOEM, 2012).
Screening is an effective, recommended strategy to address sleep disorders in the
workplace (ACOEM, 2012). Workers with non-traditional shift work schedules and workers who
work overtime or rotating shifts should be identified and periodically screened for signs and
symptoms of SWSD such as sleepiness and insufficient sleep. A health risk assessment (HRA)
should include questions specifically targeted to sleep habits and should be incorporated into an
existing health promotion program. Workers who give positive responses to risk factors for
SWSD could be prompted to questions more specific to fatigue and sleep habits. Questionnaires
such as the Berlin Questionnaire, Epworth Sleepiness Scale (Figure 3.1), Insomnia Severity
Index, or Occupational Impact of Sleep Disorder Questionnaire have all been used to assess
worker fatigue and sleep issues. Pre-placement screening for workers who have jobs with
rotating shifts or atypical hours should be done before exposing them to adverse or atypical work
schedules and sleep times. Sleep health questions, a sleep diary, and a general health history
could provide information about workers’ baseline status and, if done periodically, could be
helpful to alert the OEHN to any changes. If further assessment is indicated, the OEHN can
initiate referral to an occupational health physician or sleep medicine specialist.
32
FIGURE 3.1
EPWORTH SLEEPINESS SCALE
“It is important that you answer each question as best you can”
Situation
Sitting & reading
Watching TV
Sitting inactive in a public place
(e.g., theatre)
As a passenger for an hour without
a break
Lying down to rest in the afternoon
Chance of
Dozing
Scoring Scale
0 = would never doze
1 = slight chance of dozing
2 = moderate chance of dozing
3 = high chance of dozing
A score of less than 8 indicates
normal sleep function
8-10 = mild sleepiness
11-15 = moderate sleepiness
16-20 = severe sleepiness
21-24 = excessive sleepiness
Sitting & talking to someone
Sitting quietly after lunch without
alcohol
In a car, while stopping for a few
minutes in traffic
Total Score
Source: Johns, 1997
33
Planning
Upper level managers must be engaged early in the planning phase to provide resources
for support staff, paid employee time to attend activities, and equipment and educational
materials in order to effectively conduct a program targeted to address SWSD (ACOEM, 2012).
The OEHN, along with OESH colleagues, must determine goals and objectives which reflect the
health and safety issues in the workplace, available resources, and strategies to address them.
Education and training opportunities should include workers and managers at all levels of the
organization. Since many sleep hygiene recommendations involve the home environment, family
engagement is necessary to support workers’ needs. Employers may contract with companies
such as Circadian 24/7 Workforce Solutions™ to provide shift work training programs to
workers, or utilize internal programs and activities which could be expanded to address the
issues and wellness needs unique to shift workers (Circadian 24/7 Workplace Solutions, 2014).
Program sustainability could be enhanced by utilizing materials from agencies, such as the
American Academy of Sleep Medicine, Circadian Disorders Network, Harvard Medical School
Division of Sleep Medicine, National Institute for Occupational Safety and Health, National
Sleep Foundation, or contacting a local sleep medicine clinic or department to provide education
and resources.
Supervisors and managers at all levels of the organization should be involved in
planning and promoting fatigue recognition and management programs. Planning should be
based on research and best practice findings with interventions tailored to the needs of the
specific workers so that they are relevant to them. According to the NIOSH (2014),
Workplaces vary in size, sector, product, design, location, health, and safety experience,
resources, and worker characteristics such as age, training, physical, and mental
34
abilities, resiliency, education, cultural background, and health practices. Successful
programs recognize this diversity and are designed to meet the needs of both individuals
and the enterprise. (p. 2)
Implementation
The OEHN should communicate to organizational leaders about the benefits of
decreasing SWSD and fatigue-related issues in the workplace. Interventions to address SWSD
would positively affect an organization’s strategic goals and should become a key guiding
principle for which all organizational leaders are held accountable.
According to Rogers (2003), for most organizations, the best strategy for health program
implementation is timely and organized planning that allows programs to be phased in over time.
ACOEM (2012) identified key features which were defined by Moore-Ede (2009) as essential to
the success of fatigue risk management systems implementations. Implementation strategies can
include education and training programs, health promotion activities, and workplace policy and
practice revisions. They are supported by science, designed with input from all stakeholders,
based on analysis of assessment data, integrated into the health and safety management system,
evaluated and improved, budgeted and justified by accurate return-on-investment data, and
accepted by corporate leadership (ACOEM, 2012).
Education/Training
A well designed sleep hygiene and lifestyle education training program, developed to
teach employees and their families about managing a life of shift work, may include topics such
as:

Circadian rhythms, sleep disorders, and the importance of adequate sleep,

Sleep hygiene and fatigue management,
35

Hazards associated with working while fatigued and the benefits of being well rested,

Alertness strategies,

Recognizing fatigue and sleepiness in oneself and coworkers,

Dietary and nutrition strategies and digestive disorders,

Exercise and activity,

Stress management techniques, and

Family responsibilities, relationship and marital issues (ACOEM, 2012).
Topics should be tailored to meet the needs of the audience. Specific programs which
provide information and training on risks associated with shift work and insufficient sleep will
increase understanding of fatigue and SWSD and may assist workers in developing individual
coping strategies. Whether programs are designed by the OESH team or services are purchased
from a contracted agency, information should be available to workers, their families, and
supervisors. Workers should be encouraged to report any fatigue-related problems in the
workplace to their supervisors or the occupational health services. They should also be urged to
adopt and maintain healthy behaviors and fatigue management practices outside of work and
avoid sacrificing sleep for social activities, hobbies, or additional employment (ACOEM, 2012).
The OEHN should educate supervisors about SWSD and how to recognize the signs of
excessive fatigue among workers (Figure 3.2) (ACOEM, 2012). Employees who these signs
should be coached to mitigate fatigue with strategies, such as taking an exercise (e.g., walking or
stretching) break, consuming caffeine followed by a brief nap, or increasing social interactions
with a ‘buddy’ approach. Increased lighting and use of music may also be helpful to stimulate
wakefulness. Activities which are more hazardous should be either assigned to another worker
36
FIGURE 3.2
SIGNS OF EXCESSIVE FATIGUE
An employee who presents three or more symptoms in a short period of time
is likely to be experiencing fatigue-related impairment.
Physical Symptoms
Yawning
Heavy eyelids
Eye-rubbing
Head drooping
Microsleeps
Mental Symptoms
Emotional Symptoms
Difficulty concentrating on
tasks
More quiet or withdrawn than
normal
Lapses in attention
Lacking in energy
Difficulty remembering tasks
being performed
Lacking in motivation to do the
task well
Failure to communicate
important information
Irritable or grumpy with
colleagues, family or friends
Failure to anticipate events or
actions
Accidentally doing the wrong
thing
Accidentally not doing the
right thing
Source: ACOEM, 2012
37
who is more alert, or performed at another time (ACOEM, 2012). Fatigued employees should
also receive a written or computer-based review of sleep hygiene and fatigue management
education to increase awareness so that they will learn to take breaks before becoming
excessively fatigued (ACOEM, 2012). If repeated bouts of fatigue are seen in workers,
supervisors should inform the OEHN or the occupational health services for further evaluation.
The OEHN should encourage supervisors, and managers to alleviate or adjust work
schedules which are not conducive to circadian timing and achieving adequate sleep. Human
resources personnel should be educated about implementing hiring practices which promote
staffing levels which reduce overtime and extended hours work.
Incident Investigation
According to the Occupational Health and Safety Association (OSHA), all actual or ‘near
miss’ injury related incidents should be investigated in order to uncover hazards and identify the
root causes of the incidents (U.S. Department of Labor, 1996). Incident review teams should be
trained to assess the contribution fatigue may have played in workplace accidents and injuries
and ‘near miss’ events (ACOEM, 2012). The work schedule, sleep amount, and sleep pattern of
the worker(s) involved, as well as the start time of the shift and time of day the incident occurred
should be considered. Interviews with the involved employees may reveal performance
impairments which identify fatigue or SWSD as a contributing factor. Lapses of attention,
memory, alertness, reaction time, problem-solving ability, or changes in mood, and attitude or
physiological signs (such as slurred speech or reduced dexterity) may establish a link between
fatigue and unsafe acts or decisions (ACOEM, 2012). The OEHN may review the worker’s
health conditions, medication use, and sleep history to determine if disrupted or fragmented sleep
was apparent. Investigation should also include employees who were not directly involved in the
38
incident, but may have contributed to it. An example may be a worker who failed to properly
inspect or repair a vehicle due to inattention from fatigue, which lead to an accident involving
other employees who used the vehicle. A series of incident investigations may reveal data
suggestive of fatigue, which may not have been apparent from evaluation of a single incident
(ACOEM, 2012).
Referrals
If SWSD or fatigue-related issues are identified, the OEHN may refer workers to the
Employee Assistance Program (EAP) as needed to address personal issues (family, stress,
financial, etc.). Work and family life integration and stress management are often more
challenging issues for shift workers and those with sleep disorders. Ideally, services should be
available to workers, families, and significant others, easily accessible for workers on all shifts,
at no cost for a certain number of visits, and confidential. Workers should also be aware that they
can access these services without a referral, particularly if they have limited access to the OEHN.
Referral to the occupational health care provider is warranted if ill health effects associated with
shift work are present, or pre-existing health conditions are exacerbated. More extensive testing
and treatment, possibly bright light or pharmacological treatments, may require referral to a sleep
specialist (ACOEM, 2012).
Work Design
Monotonous work is more conducive to mental fatigue and workers may have difficulty
focusing attention on tasks (ACOEM, 2012). The OEHN may need to explore adjusting
workloads based on decreased staffing levels on non-traditional shifts. Tasks which require
assistance may not be possible on off shifts. High-risk work activities and critical tasks should be
confined to times when two or more workers are present and avoided from 3 to 5 a.m. when
39
circadian alertness is at the lowest (ACOEM, 2012). Social interaction and conversation can be
useful to increase alertness. Solitary work tasks may not be as well tolerated as during active,
daytime hours and the utilization of a ‘buddy’ approach to increase social interaction would
allow workers to monitor each other for signs of fatigue (ACOEM, 2012). Other measures
recommended by ACOEM (2012) to address the risks associated with fatigue include
maintaining communication between workers at all times, and rotating routine, sedentary tasks
with physical tasks to increase alertness and to decrease physical fatigue. Heavy physical work,
as well as work which requires constant attention, may require more frequent breaks during the
night shift to prevent fatigue (ACOEM, 2012). Work which is self-paced is preferable to
machine-paced work so that workers may vary the speed based on fatigue levels (ACOEM,
2012). Shift start and end times should be designed around availability of public transport if
possible so that fatigued workers may not need to drive. Fatigued employees should be given an
opportunity to take a short nap before driving home near or at the end of the shift to decrease the
likelihood of accidents while driving fatigued (National Highway Traffic Safety Administration,
2011).
Workplace Conditions
High levels of vibration, noise, or high temperatures are associated with higher levels of
fatigue-related behavior (Government of Canada, 2011). Workers should be allowed to control of
the temperature in the work area if possible. Outside night temperatures are often cooler than
daytime temperatures and circadian rhythms cause body temperatures to drop resulting in the
need for additional warmth. Natural ventilation by fresh air is preferred when possible, but if
forced air systems are used they should be well maintained and proper humidity should be
maintained since elevated humidity and temperature may increase drowsiness.
40
Workplace lighting should be bright enough to work safely and prevent eye strain. Bright
lights have been shown to trigger changes in the internal body clock which may aid adaptation to
night work by increasing alertness and reducing sleepiness by partial resetting of the circadian
system while at work (Health and Safety Executive, U.K., 2006). Some evidence suggests that it
is possible to wear blue light filtering goggles at night which filter the part of the light spectrum
responsible for melatonin suppression (the unwanted consequences of light at night) but not the
alertness stimulating part (Moore-Ede, Richardson, & Chacko, 2011). Employers should ensure
that parking areas are well lit and secure during off hours.
Isolated areas in the workplace should be equipped with video surveillance so that
workers can be observed for alertness at regular intervals during the shift. Sleeping quarters or
transport services for sleep impaired workers who have long distances to commute or are
required to work extended hours should be considered since multi-million dollar settlements
have been awarded to families of victims as a result of lawsuits filed against individuals as well
as businesses whose employees were involved in drowsy driving crashes (NSF, 2015b). Training
and education, mandatory meetings, and or performance reviews should be provided at times and
in a way that workers are not delaying or compromising their sleep time.
Access to Care
According to Knauth and Horberger (2003), emergency responders and first aid services
should be available on all shifts so that shift workers have access to care and occupational health
services. Health and safety professionals should ensure that first responders and emergency
response teams have access to supplies and equipment 24 hours a day. The OEHN must assure
that there is a process in place to receive reports about health and safety incidents on off shifts so
follow-up care can be provided in a timely manner.
41
Resources
Guidance to manage SWSD and fatigue in the workplace from sources such as the
NIOSH and ACOEM will ensure that interventions are evidence-based. Rotating shifts in a
clockwise manner, (i.e., the new shift will have a start time that is later than the last shift) have
been found to be easier for workers to adapt to since it is easier to stay up late than to go to bed
early (AASM, 2014b).
Through the Total Worker Health™ initiative, NIOSH is developing and evaluating
tailored training programs for managers and workers in many industries, including
manufacturing, mining, nursing, retail, and trucking which inform them of the importance of
sleep and the risks linked to insufficient sleep, shift work, and long work hours and strategies to
prevent these risks (NIOSH, 2012). Other on-line resources which could be helpful for both
employees, families and supervisors include: National Sleep Foundation, American Academy of
Sleep Medicine, Circadian Sleep Disorders Network, Sleepnet, Shift work Solutions, and
Circadian Technologies®.
Evaluation
Evaluation of interventions should begin in the planning phase of any program.
Evaluation will demonstrate the extent to which a comprehensive program to manage SWSD has
met and is meeting goals and objectives and desired program outcomes (Rogers, 2003).
Evaluation metrics should reflect if interventions have been effective in mitigating the negative
effects of fatigue.
Leading and Lagging Indicators
ACOEM recommends that both leading (those which focus on prevention based
activities) and lagging (those which are focused on past outcomes) indicators be used to evaluate
42
effectiveness of interventions (Beyer, 2011). Leading indicators could include monitoring both
the number of training sessions held for shift workers and also if the training was provided
effective manner and learning occurred as evidenced by post learning test scores. Screening and
referral activities for workers who were found to have sleep disorders should be monitored to
determine if they were timely and if employees with SWSD were successfully managed and
accommodated with modified duty when appropriate. Focus groups, questionnaires, and
interviews could be used to determine if workers felt they were achieving better sleep outcomes.
A questionnaire which addresses worker fatigue could be a good overall indicator of program
effectiveness and if administered periodically could serve as a basis for comparison.
Observations of workers or focus groups might be used to determine if workers are responding
positively to changes in work tasks or physical environment which have been implemented.
Data such as absenteeism, overtime work, and staff retention rates among shift workers
could be part of the evaluation parameters. Performance and productivity metrics could be
stratified to compare outcomes on nontraditional work periods to those of typical day work
periods.
Lagging indicators such as the average cost per indemnity claim, Workers’ Compensation
Experience Modification Rating (EMR), OSHA Recordable Incident Rate, and the Days Away,
Restricted or Transferred (DART) rate could be used. The Workers’ Compensation claims and
OSHA data could also be stratified by shift to determine if frequency or severity (i.e., lost or
modified duty cases) has decreased. Employers who are self-insured may have access to
aggregate employee medical claim trends and would be able to monitor utilization of health care
services as an indicator.
43
CHAPTER IV
IMPLICATIONS FOR THE OCCUPATIONAL AND ENVIRONMENTAL
HEALTH NURSE
To successfully mitigate the negative consequences of SWSD, prevention activities may
include nutrition, physical activity, and psychosocial interventions which are tailored to the needs
of shift workers. Secondary prevention activities which emphasize early recognition, accurate
treatment, and appropriate job placement of workers with SWSD are also necessary. Tertiary
prevention efforts should be aimed at rehabilitation of workers with SWSD to maximize function
and minimize disability. Each of these will be discussed.
Primary Prevention
Primary prevention services are those activities aimed at prevention of SWSD by
addressing individual or organizational factors which may be modified. Education about shift
work and associated risks should be a part of the primary prevention measures for all shift
workers and managers. The content of the educational program for shift workers should be
tailored to meet the needs of the workers and delivered in an effective manner. Language barriers
or cultural traditions must be recognized so that the content is not only relevant but delivered
appropriately. If possible, learning activities should be accessible 24 hours or, if a classroom
format is used, offered on all shifts. Learning opportunities should be provided during scheduled
work time as opposed to non-working time so they do not infringe on sleep time.
To maximize efficiency and effectiveness of services, the OEHN may consult with other
organizations which employ shift workers and have proven programs to address fatigue-related
issues. Health care facilities (such as a local sleep disorders center), or community or public
44
health agencies may provide valuable materials or resources. Supervisors and managers may
assist in educating workers about SWSD and the importance of sleep if they have received
training about fatigue-related issues. Special attention should be given to educating
supervisors/managers about addressing worker fatigue issues which may appear to be
performance issues. The misperception that SWSD is a behavioral problem, caused by personal
irresponsibility more than an actual physiological disorder may need to be dispelled (Circadian
24/7 Workplace Solutions, 2014).
Since shift workers are at a higher risk of cardiovascular diseases, focused programs may
be indicated for this group of workers. High fat meals consumed during the night pose more risk
to workers than equivalent meals consumed during the day, so dietary education is more
important.
Physical activity helps prevent cardiovascular disease and may help facilitate circadian
adaptation to schedules requiring a delay in the sleep-wake cycle (Barger, Wright, Hughes, &
Czeisler, 2004). Exercise also improves general mood and promotes alertness on night shift
(American College of Emergency Physicians, 2014). Obesity and heart disease are major health
care cost drivers in most U.S. organizations, and the OEHN should provide organizational
leaders with current evidence about how shift work adds to this burden and how a fatigue risk
management system presents an opportunity to increase worker safety, health, and productivity
(ACOEM, 2012). Rotational schedules and overtime practices which present risks to worker
health should be evaluated and adjusted when possible.
Safety specialists and engineers, ergonomic consultants, EAP personnel, and human
resources representatives should play a part in prevention activities as well. Safety specialists
who track and investigate injuries should be astute to fatigue-related events. Ergonomic
45
consultants may need to reconfigure job tasks and work designs on a third shift, for instance due
to decreased lighting or because they require increased attention. EAP personnel may offer
prevention strategies to groups or individual shift workers before issues arise. Human resources
personnel may work with managers and supervisors to determine employment practices which
do not require employees to rotate shifts too rapidly or rotate forward, and may consider limiting
the amount of time an employee remains on a nontraditional, especially rotating, shift.
Secondary Prevention
Secondary prevention efforts should emphasize early recognition and treatment for
symptoms and issues caused by SWSD, and case management and job accommodation. The
OEHN should be aware of the available treatment options and best practice treatment strategies
so that they can be applied to the workplace (Rogers et al., 2009). Referral to an occupational
health physician or sleep specialist should be initiated if more sophisticated testing and analysis
of sleep patterns (polysomnography) is indicated. The OEHN may ascertain how the worker will
best have his/her issues met and help the worker access the appropriate provider.
The diagnosis of SWSD includes a physical examination as well as a medical and sleep
history. Medical or psychological illnesses which could be contributing to the sleep disorder
should be addressed. Treatment may include improved management of underlying health
conditions which may contribute to fatigue or insomnia such as substance abuse, underlying
sleep disorders, or general lifestyle issues.
The OEHN may collaborate with supervisors to determine a plan to meet the worker’s
capabilities which could include modifications to work duties. In the case management role, the
OEHN may collaborate with managers and human resources personnel to assist the employee
with initiating time off for care and recovery as required.
46
Tertiary Prevention
Tertiary prevention includes ongoing treatment or therapy to limit untoward effects of
SWSD. In some cases, transfers to day work may be indicated for workers who cannot
successfully cope with shift work. Return to shift work after removal should be carefully
evaluated by the worker and all health care providers involved. A fitness for duty examination
may be useful in some cases. Denmark was the first country to pay government compensation to
women who developed breast cancer after long periods of working at night (Chustecka, 2009).
Other European countries are considering similar policies but currently Workers’ Compensation
in the U.S. does not recognize SWSD as a compensable, work-related disability in most cases
(Bird, 2007). The Americans with Disabilities Act (ADA) offers broader inclusive language for
accommodating employees suffering from injuries/illness than the Workers’ Compensation law
(Bird, 2007; U.S. Equal Employment Opportunity Commission, 1990). The OEHN may likely
need to collaborate with the worker’s primary care provider or sleep specialist when determining
an appropriate, rehabilitative plan for a worker with SWSD.
47
CHAPTER V
CONCLUSIONS/RECOMMENDATIONS
Conclusions and Recommendations
A comprehensive workplace program to manage SWSD requires an interdisciplinary
approach with all members of the occupational health team. Through collaboration with senior
corporate leaders, managers, and human resources personnel, the team can provide input to craft
policies and procedures with appropriate shift work schedules and workloads. Sleep disorders
and disturbances of sleep comprise a broad range of problems which reach across the entire
organization and require a multidisciplinary approach to address them. Recent literature about
shift work identifies several opportunities to address individual and organizational factors to
improve shift worker adaptation and functioning (Richter et al., 2010).
Despite strong evidence of the relationship between insufficient sleep and health
problems, many people are unaware of the amount of sleep they need, their level of sleep
deprivation, and the negative impact of sleep deprivation on health. Occupational health
professionals should bring sleep hygiene to the forefront of health promotion and disease
prevention programs. For example, business leaders may be unaware of the burden SWSD poses
to productivity and may need metrics related to both direct and indirect costs related to SWSD
and fatigue-related issues. Workers and families may lack education as to how to adapt a
home/family environment to a shift worker.
There is growing evidence that understanding the inter-individual variability in sleep–
wake responses to shift work will help detect and manage workers who are most vulnerable to
the health consequences of shift work (Rajaratnam et al., 2013). The OEHN is in a unique
48
position to recognize the differences among workers and share information regarding
anticipating workers who may be at high risk.
Given expertise in health promotion planning, injury care and treatment, counseling, and
case management of workers, policy development, legal and ethical compliance monitoring, and
applying research findings, the OEHN is well positioned to collaborate with many disciplines in
the workplace (Rogers, 2003). Case management skills are required to enable the worker to
obtain the most effective and efficient care and return to the work. The OEHN may also act as
the community liaison when additional resources, which extend beyond the scope of the
employer, are needed to assist employees.
As the need for shift work grows, workers, their families, employers, and policy-makers
need relevant, and high-quality evidence about the effectiveness of different interventions to
address SWSD. Shift work is commonly associated with adverse safety and health consequences
and many companies have taken measures to address these issues but there is a lack of scientific
evaluation of these programs. Circadian misalignment, sleep loss and sleep disorders all
represent hazards in the workplace, and therefore SWSD and fatigue in the workplace needs
further study and evaluation. The goal is for improved methods to accurately detect those who
are most vulnerable to the effects of shift work. According to the Occupational Cancer Research
Centre and the Institute for Work & Health (2012) in Canada, “innovative, evidence-based
prevention efforts must be developed and evaluated to simultaneously meet the unique health
needs of shift workers and the mandates of the organizations and industries in which they work”
(p. 4).
A comprehensive education program for air traffic controllers implemented in Canada
noted the following intentions to be integral to the success of the program:
49
1. Organizational commitment
2. Employer-employee partnership
3. Education and training
4. Employee health screening
5. Program evaluation and refinement (Richter et al., 2010).
Progress is being made to study the issues of the fatigue and SWSD and to disseminate
guidance to employers and members of the occupational health and safety community. The 2011
National Institutes of Health (NIH) Sleep Disorders Research Plan identified five key goals for
sleep and circadian science:
Goal 1 - Advance the understanding of sleep and circadian functions and of basic sleep
and circadian mechanisms, in both the brain and the body, across the lifespan.
Goal 2 - Identify genetic, pathophysiological, environmental, cultural, lifestyle factors
and sex and gender differences contributing to the risk of sleep and circadian disorders
and disturbances, and their role in the development and pathogenesis of co-morbid
diseases, and disability.
Goal 3 - Improve prevention, diagnosis, and treatment of sleep and circadian disorders,
chronic sleep deficiency, and circadian disruption, and evaluate the resulting impact on
human health.
Goal 4 - Enhance the translation and dissemination of sleep and circadian research
findings and concepts to improve health care, inform public policy, and increase
community awareness to enhance human health.
50
Goal 5 - Enable sleep and circadian research training to inform science in crosscutting
domains, accelerate the pace of discovery and the translation of enhanced therapies from
bench to bedside to community (NIH, 2011, p. 4-5).
The National Occupational Research Agenda (NORA) Work Organization and StressRelated Disorders Team is charged with defining and implementing a national occupational
research agenda for the next decade. A NORA Long Work Hours Sub team was formed to
address overtime and extended work shifts (NIOSH, 2014).
The negative impact of shift work and SWSD needs to be acknowledged. Industries have
demonstrated greater productivity and increased job satisfaction by using scheduling practices
which are based on circadian principles (Circadian 24/7 Workplace Solutions, 2014; Sack et. al.,
2007) but continued research is needed. OEHNs, occupational health and safety professionals,
public health leaders, and workers should advocate for strategies to more effectively prevent and
manage SWSD.
Future Research
There have been limited studies of workers’ personality traits, preferences, and resilience
to shift work (Storemark et al., 2013), and future research is needed to determine if there are any
factors which could predict tolerance to shift work and more specifically predict those who may
be at higher risk for SWSD. This would allow for more appropriate placement of workers to
positions suited to their capabilities and also not placing workers in jobs which put them at
higher risk. In addition, more research and collaboration between sleep medicine and
occupational health and safety is needed to determine which shifts and rotational patterns are
associated with the highest degree of circadian disruption and which mitigation strategies are the
most effective at preventing long-term consequences or progression of SWSD.
51
The long-term consequences of SWSD have not been studied adequately in workers who
retire or leave the workplace after several years of shift work or SWSD. It is also not well
understood how sleep disturbances affect aging workers which will be particularly significant as
the working population ages since individuals are living and working longer.
The impact that shift work, fatigue, and sleep-related disorders have on health and safety
is emerging on the public health agenda, and in occupations such as nursing and health care,
attempts are being made to educate workers about their risks. As more compelling research
arises, work processes and legislative policies limiting shift work, like any other known hazard in
the workplace, may be indicated. Cases of SWSD or other fatigue-related issues which are
clearly work associated may become OSHA recordable or even compensable as disability claims,
as they are in some other countries.
It is evident that organizations should question if the amount of shift work for individual
workers should be reduced to mitigate the risk for SWSD. If this is not possible, then
interventions should be instituted early, in a proactive manner rather than later. Research is
needed to determine which workers are at highest risk for SWSD and which interventions prove
the most effective to prevent or treat it. The findings should then be disseminated so that
organizational policies and procedures can be changed to reflect best practice. Federal and state
labor laws should also reflect research findings about overtime, extended hours, and shift work to
protect, preserve, and enhance workers’ health and safety.
52
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