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National electronic Library for Medicines
Medicines Management Overview
September 2011
DRUG-RELATED PROBLEMS CAUSING HOSPITALISATION
AN UPDATE
Contents
Summary
Key findings
Annotated
bibliography
1
2
3
Produced for the National
electronic Library for
Medicines by:
Tom Burnham, Information
Specialist, London and
South East Medicines
Information Service, Guy’s
Hospital, London SE1 9RT
Tel: 020 7188 5026
[email protected]
Summary
One objective of the QIPP programme is to minimise
avoidable admissions to hospital, which are not only
responsible for a large cost burden, but also have an
impact on patient safety.
There is general agreement that drug-related
problems are responsible for an appreciable
proportion of hospital admissions and that a
substantial proportion of these problems are
potentially preventable. Drug-related problems
include not only adverse drug reactions (ADRs) in the
strict sense, but also other types of adverse drug
events, such as failure by the patient to adhere to
prescribed treatment, various types of medication
errors, inappropriate treatment, failure to prescribe
indicated treatment, and drug interactions.
This report summarises recent publications (mostly
in 2010 and 2011) which attempt to quantify the
contribution of drug-related problems to the overall
level of patient admissions to hospital. It does not
consider studies referring only to a specific
medication or a specific medical condition.
Key Findings
A review from the School of Pharmacy and Pharmaceutical Sciences, University of
Manchester1 found that the prevalence of ADRs in patients admitted to hospital
was a median of 5.3%, with a somewhat lower incidence in children and
somewhat higher in elderly patients. However, the range varied widely between
individual studies (0.16% to 15.7%). The authors admit that there was
considerable variation in the definitions used for ADRs. A larger review2 found a
range for prevalence of medication-related hospitalisation from 0.1% to 54% but
draws attention to a number of methodological problems which make it difficult to
pool data from different sources. An earlier review3 including 25 studies had also
encountered problems of definition, but concluded that a median of 5.8% of
admissions to medical departments were caused by ADRs.
A study using the Hospital Episode Statistics database for all English hospital
admissions (1999-2008)4 found that ADR-associated admissions represented
0.9% of all hospital admissions for the period, considerably lower than the
findings of the above reviews, or of most individual studies.
Similar results were obtained for all acute hospital admissions in Spain in 20012006 (1.69% due to ADRs)5 while in the Netherlands a figure of 0.44% was found
for ADR-related admissions in 2000-20056. In this case, there was a small but
significant difference in the rates between men (0.41%) and women (0.47%).
Higher rates have been found in studies using data for individual hospitals or
groups of hospitals. For example, 4% of unplanned admissions to the main
wards of the Royal Liverpool Children’s Hospital over a 2-week period were
attributed to ADRs7. Two studies in emergency units in Canada8,9 found figures of
2.4% and 4.7% respectively (and the second study investigated whether doctors
always recorded presentations due to ADRs as medication related). A study in
Germany10 found that 3.25% of a sample of some 57,000 hospitalisations were
caused by serious outpatient ADRs, and presented a cost analysis. Similarly, the
HARM study in the Netherlands11 found that 5.6% of unplanned admissions to 21
hospitals over 40 days were medication related, and the authors later presented a
cost analysis12 showing average costs of Euro 6009 for one, potentially
preventable, medication-related hospital admission for all ages.
In line with a generally higher incidence of ADRs in older patients, an Italian
study found that 5.6% of admissions to a geriatric unit were caused by definite or
probable ADRs13.
A study in Barcelona, Spain, found that medication-related problems (not just
ADRs) were wholly or partially involved in as many as 12% of admissions14.
Davies et al.15 found that 20.8% of emergency readmissions within one year were
due to ADRs, of which more than half were considered avoidable. This adds
interest to the findings of an analysis of integrated medicines management of
elderly inpatients in Lund, Sweden, by a multidisciplinary team including a clinical
pharmacist16, which was found to reduce the number of drug-related emergency
re-admissions.
Finally, a study of the causes of preventable drug-related admissions (PDRAs) to
a hospital in Nottingham17 found that they were complex and multi-faceted, and
concluded that a solution would need to address human factors in addition to
technical aspects.
Annotated Bibliography
1) Hospital admissions associated with adverse drug reactions: a systematic
review of prospective observational studies
C Kongkaew, PR Noyce, DM Ashcroft
Annals of Pharmacotherapy, Jul-Aug 2008, vol. 42, no. 7-8, p. 1017-1025
25 studies were identified including 106,586 patients who were hospitalised; 2143 of these
patients had experienced ADRs. The prevalence rates of ADRs ranged from 0.16% to 15.7%,
with an overall median of 5.3%. Higher rates were found in elderly patients who are likely to
be receiving multiple medications for long-term illnesses. The methods used to detect ADRs
are also likely to explain much of the variation in the reported ADR prevalence rates between
different studies. (54 refs.)
http://www.theannals.com/content/42/7/1017.abstract
2) The relationship between study characteristics and the prevalence of
medication-related hospitalizations: a literature review and novel analysis
AJ Leendertse, D Visser, ACG Egberts, PMLA van den Bemt
Drug Safety Mar 2010;33(3):233-244
Background: Studies on medication-related hospitalisations differ in study setting, studied
population, outcome, and method of data collection. Thus, extrapolations based on a metaanalysis of unselected studies may be biased.
Objective: To explore the influence of study characteristics on the prevalence of medicationrelated hospitalisations.
Methods: After a structured literature search, the retrieved studies were categorised based
on the following aspects: (i) study setting (e.g. all hospital admissions vs only acute hospital
admissions); (ii) study population (e.g. an entire hospital, study ward(s), selected population
and/or age group); (iii) outcome of medication-related problem (e.g. adverse drug reaction
[ADR] vs adverse drug event [ADE]); (iv) method of data collection (e.g. medical chart review,
spontaneous reporting or database research); and (v) continent in which the study took place
(only for studies looking at all acute admissions). Authors then examined the relationship
between these factors and reported prevalence of medication-related hospital admissions.
Results: Ninety-five studies were analysed, with a range of reported prevalence of
medication-related hospitalisations from 0.1% to 54%. Higher prevalences were found in the
studies examining all hospital admissions than in the studies examining only acute hospital
admissions. In addition, higher prevalences were found in the elderly population than in
children. As would be expected, higher prevalences were also found in studies examining
ADEs than in studies examining only ADRs. With respect to the method of data collection,
medical chart screening resulted in higher prevalences of medication-related hospitalizations
than database methods or spontaneous reporting. Combined studies in Europe show lower
prevalences of medication-related hospital admissions than in other continents included in the
study.
Discussion: The reported prevalence of medication-related hospital admissions varies as a
function of the setting (all admissions or only acute admissions), studied population (entire
hospital, specific wards, selected population and age group), outcome (ADR/ADE), the
method of data collection and the continent in which the study is performed.
Conclusion: Extrapolation using national hospital admission data and the prevalence
identified by pooling international studies should be carried out with great caution. (103 refs.)
http://adisonline.com/drugsafety/Abstract/2010/33030/The_Relationship_Between_Study_Ch
aracteristics_and.5.aspx
3) Adverse drug reaction monitoring - cost and benefit considerations. Part I:
Frequency of adverse drug reactions causing hospital admissions
N Muehlberger, S Schneeweiss, J Hasford
Pharmacoepidemiology and Drug Safety, 1997, vol. 6, no. Suppl.3, p. S71-S77
Paper presented at the European Society of Pharmacovigilance 4th Annual Meeting, Lisbon,
Portugal, 1996. The objective of this paper is to summarise all original work on ADR
frequencies at hospital admission and to come up with a valid estimate for the actual
frequency of ADR-related hospital admissions. Additionally, established concepts of ADR
monitoring were compared with respect to their utility for drug safety monitoring and
pharmacoepidemiological research. 25 studies from the past 25 years were reviewed.
Analysing the effect of methodological characteristics showed that variation of reported ADR
frequency mainly depends on differing study bases and the concepts of ADR monitoring.
Investigations that thoroughly screened all members of the study population for the presence
of adverse drug reactions (comprehensive ADR monitoring) generally yielded highest ADR
proportions. Studies that concentrated screening on selected high-risk patients (preselective
ADR monitoring) and those applying spontaneous or intensified spontaneous reporting
detected lower ADR proportions (2.9% and 2.5%). The ADR proportion among admissions to
departments of internal medicine was higher than among mixed hospital populations including
surgical patients. In conclusion 4.2-6.0% (lower and upper quartile) and in median 5.8% of all
admissions to medical departments are caused by adverse drug reactions. A 2-step
preselective ADR monitoring appears to be appropriate and efficient for both signal
generation and signal validation as compared to spontaneous reporting and comprehensive
monitoring. In conclusion, adverse drug reactions are a common cause of hospital
admissions. As hospital care is expensive, attempts to prevent ADR and thus hospital
admission need active encouragement.
http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1099-1557(199710)6:3%2B%3CS71::AIDPDS282%3E3.0.CO;2-I/abstract
4) Ten-year trends in hospital admissions for adverse drug reactions in England
1999-2009
T-Y Wu, M-H Jen, A Bottle, M Molokhia, et al.
Journal of the Royal Society of Medicine Jun 2010;103(6):239-250
Objectives: Adverse drug reactions (ADR) are an important cause of morbidity and mortality.
We analysed trends in hospital admissions associated with ADRs in English hospitals
between 1999 and 2008.
Design: Data from the Hospital Episode Statistics database were examined for all English
hospital admissions (1999-2008) with a primary or secondary diagnosis of an ADR recorded.
Setting: All NHS (public) hospitals in England.
Main outcome measures: The number of admissions and in-hospital mortality rate with a
primary (codes including 'adverse drug reaction', 'drug-induced', 'due to drug', 'due to
medicament' or 'drug allergy') or secondary diagnosis of ADR (ICD-10 Y40-59) were obtained
and analysed. Further analysis for the year 2008-09 was performed with regard to age,
gender, proportion older than 65 years and total bed-days.
Results: Between 1999 and 2008, there were 557,978 ADR-associated admissions,
representing 0.9% of total hospital admissions. Over this period the annual number of ADRs
increased by 76.8% (from 42,453 to 75,076), and in-hospital mortality rate increased by 10%
(from 4.3% to 4.7%). In 2008, there were 6,830,067 emergency admissions of which 75,076
(1.1%) were drug-related. Systemic agents were most commonly implicated (19.2%),
followed by analgesics (13.3%) and cardiovascular drugs (12.9%). There has been a near 2fold increase in nephropathy and cardiovascular consequences secondary to drugs and a
6.8% fall in mental and behavioural disorders due to drugs.
Conclusions: ADRs have a major impact on public health. Our data suggest the number of
ADR admissions has increased at a greater rate than the increase in total hospital
admissions; some of this may be due to improved diagnostic coding. However, in-hospital
mortality due to ADR admissions also increased during the period. Our findings should
prompt policymakers to implement further measures to reduce ADR incidence and their
associated in-hospital mortality, and methods to improve the recording of ADRs.
http://jrsm.rsmjournals.com/cgi/reprint/103/6/239
5) Trends of adverse drug reactions related-hospitalizations in Spain (2001-2006)
P Carrasco-Garrido, A Lopez de Andres, V Hernandez-Barrera, A Gil de Miguel, R JimenezGarcia
BMC Health Services Research 13 Oct 2010;10:287
Background: Adverse drug reactions (ADR) are a substantial cause of hospital admissions.
We conducted a nationwide study to estimate the burden of hospital admissions for ADRs in
Spain during a 6-year period (2001-06) along with the associated total health cost.
Methods: Data were obtained from the national surveillance system for hospital data
(Minimum Basic Data Set) maintained by the Ministry of Health and Consumer Affairs, and
covering more than 95% of Spanish hospitals. From these admissions we selected all
hospitalisations that were coded as drug-related (ICD-9-CM codes E), but intended forms of
overdoses, errors in administration and therapeutics failure were excluded. The average
number of hospitalisations per year, annual incidence of hospital admissions, average length
of stay in the hospital and case-fatality rate, were calculated.
Results: During the 2001-06 periods, the total number of hospitalised patients with ADR
diagnosis was 350,835 subjects, 1.69% of all acute hospital admissions in Spain. The
estimated incidence of admissions due to ADR decreased during the period 2001-06 (p less
than 0.05). More than 5% of patients (n=19,734) died during an ADR-related hospitalisation.
The drugs most commonly associated with ADR-related hospitalisation were antineoplastic
and immunosuppressive drugs (n = 75,760), adrenal cortical steroids (n = 47,539),
anticoagulants (n = 26,546) and antibiotics (n = 22,144). The costs generated by patients in
our study increased by 19.05% between 2001 and 2006.
Conclusions: Approximately 1.69% of all acute hospital admissions were associated with
ADRs. The rates were much higher for elderly patients. The total cost of ADR-related
hospitalisation to the Spanish health system is high and has increased between 2001 and
2006. ADRs are an important cause of admission, resulting in considerable use of national
health system beds and a significant number of deaths.
http://www.biomedcentral.com/content/pdf/1472-6963-10-287.pdf
6) Sex-related differences in hospital admissions attributed to adverse drug
reactions in the Netherlands
EM Rodenburg, BHC Stricker, LE Visser
British Journal of Clinical Pharmacology Jan 2011;71(1):95-104
Aim: Adverse drug reactions (ADRs) are a major burden in health care, regularly leading to
hospital admission, morbidity or death. Women tend to have a higher risk of adverse drug
reactions with a 1.5 to 1.7-fold greater risk than men. Our primary aim was to study
differences in ADR-related hospitalisations between the sexes.
Methods: We conducted a nationwide study of all ADR-related hospitalisations in the period
between 2000 and 2005 in the Netherlands, which were selected from all 9,287,162 hospital
admissions in this period. ADR-drug group combinations with at least 50 admissions in one
of the sexes were selected. Relative risks and confidence intervals were calculated with
respect to total admissions and total prescriptions with men as reference.
Results: In total, 0.41% of the 4,236,368 admissions in men (95% CI, 0.40, 0.42%) and
0.47% of the 5,050,794 admissions in women (95% CI, 0.46, 0.48%) were attributed to an
ADR by medical specialists (57% of all ADR-related admissions were in women). Differences
between the sexes in risk for ADR-related hospitalisation were found for antineoplastic and
immunosuppressive drugs, antirheumatics, anticoagulants and salicylates, cardiovascular and
neurological drugs, steroids and antibiotics. In certain drug categories, risks for
hospitalisation changed after taking into account total drug prescriptions.
Conclusions: In all different drug classes, significant differences exist between the sexes in
ADR-related hospital admissions. Cardiovascular drugs account for the most pronounced
differences between men and women. More research is needed to explain the clear sex
differences in ADR-related hospital admissions.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2125.2010.03811.x/pdf
7) Adverse drug reactions causing admission to a paediatric hospital: a pilot
study
RM Gallagher, KA Bird, JR Mason, M Peak, PR Williamson, AJ Nunn, MA Turner, M
Pirmohamed, RL Smyth
Journal of Clinical Pharmacy and Therapeutics Apr 2011;36(2):194-199
Objective: It is known that adverse drug reactions (ADRs) cause admission to hospital in adults and
children. A recent adult study showed that ADRs are an important and frequent cause of hospital
admission. The objective of this study is to develop methodology to ascertain the current burden of
ADRs through a prospective analysis of all unplanned admissions to a paediatric hospital.
Methods: Prospective observational study over a 2-week period at the Royal Liverpool Children's
Hospital.
Results and Discussion: There were 19 admissions to the main hospital wards related to an ADR,
giving an estimated incidence of 4%, with the ADR directly leading to the admission in 71% of cases.
There were no deaths attributable to ADR. 33% of the reactions were possibly avoidable. The drugs
most commonly implicated in causing admissions were antineoplastic agents. The most common
reactions were neutropenia, vomiting and diarrhoea. The health burden of ADRs in the paediatric
population is likely to be significant. This pilot study will be used to inform a much larger prospective
study providing more detailed evidence of the burden of ill-health from ADRs in children. This larger
study will add to a body of research aiming to identify drug-related problems within children to aid
paediatric pharmacovigilance.
Conclusions: This study provides knowledge regarding the methodology to be used for a larger study
investigating ADRs in children. The study will allow authors who wish to replicate the study in their own
populations (internationally) to avoid some of the pitfalls in planning a large epidemiological study of
paediatric ADRs. The study also provides an estimate of the incidence and problem of admissions
caused by ADRs in a UK paediatric population.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2710.2010.01194.x/abstract
8) Adverse drug events in adult patients leading to emergency department visits
KC Sikdar, R Alaghehbandan, D MacDonald, et al.
Annals of Pharmacotherapy Apr 2010;44(4):641-649
Background: Adverse drug events (ADEs) occurring in the community and treated in emergency
departments (EDs) have not been well studied.
Objective: To determine the prevalence, severity, and preventability of ADEs in patients presenting at
EDs in 2 university-affiliated tertiary care hospitals in the Canadian province of Newfoundland and
Labrador.
Methods: A retrospective chart review was conducted on a stratified random sample (n = 1458) of
adults (18 years and older) who presented to EDs from 1 Jan to 31 Dec 2005. Prior to the chart review,
the sample frame was developed by first eliminating visits that were clearly not the result of an ADE.
The ED summary of each patient was initially reviewed by 2 trained reviewers in order to identify
probable ADEs. All eligible charts were subsequently reviewed by a clinical team, consisting of 2
pharmacists and 2 ED physicians, to identify ADEs and determine their severity and preventability.
Results: Of the 1458 patients presenting to the 2 EDs, 55 were determined to have an ADE or a
possible ADE (PADE). After a sample-weight adjustment, the prevalence of ADEs/PADEs was found to
be 2.4%. Prevalence increased with age (0.7%, 18–44 yr; 1.9%, 45–64 yr; 7.8%, 65 yr or older) and the
mean age for patients with ADEs was higher than for those with no ADEs (69.9 vs 63.8 yr; p < 0.01). A
higher number of comorbidities and medications was associated with drug-related visits. Approximately
29% of the ADEs/PADEs identified were considered to be preventable, with 42% requiring
hospitalisation. Cardiovascular agents (37.4%) were the most common drug class associated with
ADEs/PADEs.
Conclusions: Adult ADE-related ED visits are frequent in Newfoundland and Labrador, and in many
cases are preventable. Further efforts are needed to reduce the occurrence of preventable ADEs
leading to ED visits.
http://www.theannals.com/content/44/4/641.abstract
9) Do emergency physicians attribute drug-related emergency department visits
to medication-related problems?
CM Hohl, PJ Zed, JR Brubacher, RB Abu-Laban, PS Loewen, RA Purssell
Annals of Emergency Medicine Jun 2010;55(6):493-502.e4
Study objective: Adverse drug events represent the most common cause of preventable
nonsurgical adverse events in medicine but may remain undetected. Our objective is to
determine the proportion of drug-related visits emergency physicians attribute to medicationrelated problems.
Methods: This prospective observational study enrolled adults presenting to a tertiary care
emergency department (ED) in Canada during 12 weeks. Drug-related visits were defined as
ED visits caused by adverse drug events. The definition of adverse drug event was varied to
examine both narrow and broad adverse drug event classification systems. Clinical
pharmacists evaluated all patients for drug-related visits, using standardised assessment
algorithms, and then followed patients until hospital discharge. Interrater agreement for the
clinical pharmacist diagnosis of drug-related visit was assessed. Emergency physicians,
blinded to the clinical pharmacist opinion, were interviewed at the end of each shift to
determine whether they attributed the visit to a medication-related problem. An independent
committee reviewed and adjudicated all cases in which the emergency physicians' and clinical
pharmacists' assessments were discordant, or either the emergency physician or clinical
pharmacist was uncertain. The primary outcome was the proportion of drug-related visits
attributed to a medication-related problem by emergency physicians.
Results: 944 patients were enrolled, of whom 44 patients received a diagnosis of the
narrowest definition of an adverse drug event, an adverse drug reaction (4.7%; 95% CI, 3.5%
to 6.2%). 27 of these were categorised as medication-related by emergency physicians
(61.4%; 95% CI, 46.5% to 74.3%), 10 were categorised as uncertain (22.7%; 95% CI, 12.9%
to 37.1%), and 7 categorised as a non-medication-related problem (15.9%; 95% CI, 8.0% to
29.5%). 78 patients (8.3%; 95% CI, 6.7% to 10.2%) received a diagnosis of an adverse drug
event caused by an adverse drug reaction, a drug interaction, drug withdrawal, a medication
error or noncompliance. Emergency physicians attributed 49 of these to a medication-related
problem (62.8%; 95% CI, 51.7% to 72.7%), were uncertain about 15 (19.2%; 95% CI, 12.0%
to 29.4%) and attributed 14 to non-medication-related problems (17.9%; 95% CI, 11.0% to
27.9%). 25 of 29 (86.2%; 95% CI, 69.3% to 94.4%) adverse drug events not considered
medication related by emergency physicians were rated at least moderate in severity.
Conclusions: A significant proportion of drug-related visits are not deemed medication
related by emergency physicians. Drug-related visits not attributed to medication-related
problems by emergency physicians may be missed in ongoing outpatient adverse drug event
surveillance programmes intended to develop strategies to enhance drug safety. Further
research is needed to determine what the effect may be of not attributing adverse drug events
to medication-related problems.
http://www.annemergmed.com/article/S0196-0644(09)01648-5/abstract
10) Adverse drug reactions in Germany: direct costs of internal medicine
hospitalizations
D Rottenkolber, S Schmiedl, M Rottenkolber, K Farker, et al.
Pharmacoepidemiology and Drug Safety Jun 2011;20(6):626-634
Purpose: German hospital reimbursement modalities changed as a result of the introduction
of Diagnosis Related Groups (DRG) in 2004. Therefore, no data on the direct costs of
adverse drug reactions (ADRs) resulting in admissions to departments of internal medicine
are available. The objective was to quantify the ADR-related economic burden (direct costs)
of hospitalisations in internal medicine wards in Germany.
Methods: Record-based study analysing the patient records of about 57,000 hospitalisations
between 2006 and 2007 of the Network of Regional Pharmacovigilance Centers (Germany).
All ADRs were evaluated by a team of experts in pharmacovigilance for severity, causality
and preventability. The calculation of accurate person-related costs for ADRs relied on the
German DRG system (G-DRG 2009). Descriptive and bootstrap statistical methods were
applied for data analysis.
Results: The incidence of hospitalisation due to at least 'possible' serious outpatient ADRs
was estimated to be approximately 3.25%. Mean age of the 1834 patients was 71.0 years
(SD 14.7). Most frequent ADRs were gastrointestinal haemorrhage (n = 336) and druginduced hypoglycaemia (n = 270). Average inpatient length-of-stay was 9.3 days (SD 7.1).
Average treatment costs of a single ADR were estimated to be approximately Euro 2250.
The total costs sum to Euro 434 million per year for Germany. Considering the proportion of
preventable cases (20.1%), this equals a saving potential of Euro 87 million per year.
Conclusions: Preventing ADRs is advisable in order to realise significant nationwide savings
potential. Our cost estimates provide a reliable benchmark as they were calculated based on
an intensified ADR surveillance and an accurate person-related cost allocation.
http://onlinelibrary.wiley.com/doi/10.1002/pds.2118/abstract
11) Frequency of and risk factors for preventable medication-related hospital
admissions in the Netherlands
AJ Leendertse, ACG Egberts, LJ Stoker, PMLA van den Bemt (HARM Study Group)
Archives of Internal Medicine, 22 Sep 2008, vol. 168, no. 17, p. 1890-1896
A prospective multicentre study was conducted to determine the frequency and patient outcomes of
medication-related hospital admissions. A case-control design was used to determine risk factors for
potentially preventable admissions. All unplanned admissions in 21 hospitals were assessed over 40
days. Controls were patients admitted for elective surgery. Cases and controls were followed up until
hospital discharge. The frequency of medication-related hospital admissions, potential preventability and
outcomes were assessed. For potentially preventable medication-related admissions, risk factors were
identified in the case-control study. Almost 13,000 unplanned admissions were screened, of which 714
(5.6%) were medication related. Almost half (46.5%) of these admissions were potentially preventable,
resulting in 332 case patients matched with 332 controls. Outcomes were favourable in most patients.
The main determinants of preventable medication-related hospital admissions were impaired cognition
(odds ratio, 11.9; 95% CI, 3.9-36.3), 4 or more comorbidities (8.1; 3.1-21.7), dependent living situation
(3.0; 1.4-6.5), impaired renal function (2.6; 1.6-4.2), nonadherence to medication regimen (2.3; 1.4-3.8)
and polypharmacy (2.7; 1.6-4.4). Concludes that adverse drug events are an important cause of
hospitalisations, and almost half are potentially preventable. The identified risk factors provide a starting
point for preventing medication-related hospital admissions.
http://archinte.ama-assn.org/cgi/reprint/168/17/1890
12) Preventable hospital admissions related to medication (HARM): cost analysis
of the HARM study
AJ Leendertse, PMLA Van Den Bemt, JB Poolman, LJ Stoker, ACG Egberts, MJ Postma
Value in Health Jan 2011;14(1):34-40
Objective: Adverse drug events (ADEs) can cause serious harm to patients and can lead to
hospitalisation or even death. ADEs are a burden not only to patients and their relatives, but
also to society and have the potential to involve high costs. To provide more information on
the economic burden of preventable adverse drug events of outpatients, we performed a cost
study on the data collected in the Hospital Admissions Related to Medication (HARM) study.
In this study we examined the frequency, preventability and risk factors for hospital
admissions related to medication.
Methods: The average costs for a preventable medication-related hospital admission were
calculated by summing the direct medical costs and the production losses of all the
preventable admissions, taking into account the different types of hospitals (academic and
general) and the age of the patients admitted.
Results: The average medical costs for one preventable medication-related hospital
admission were Euro 5461. The average production loss costs for one admission were Euro
1712 for a person younger than 65 years of age. Combining the medical costs and the costs
of production losses resulted in average costs of Euro 6009 for one, potentially preventable,
medication-related hospital admission for all ages.
Conclusions: The costs of potentially preventable hospital admissions related to medication
are considerable. Therefore, patient safety interventions to prevent ADEs and hospital
admissions may be cost-effective or even cost saving.
http://dx.doi.org/10.1016/j.jval.2010.10.024
13) Prevalence, clinical features and avoidability of adverse drug reactions as
cause of admission to a geriatric unit: a prospective study of 1756 patients
M Franceschi, C Scarcelli, V Niro, et al.
Drug Safety, 2008, vol. 31, no. 6, p. 545-556
Background: Drug use increases with advancing age, and in older patients it is associated
with an increase in adverse drug reactions (ADRs). ADRs are a primary cause of morbidity
and mortality worldwide. Objectives: To evaluate the prevalence, clinical characteristics and
avoidability of ADR-related hospital admissions in elderly patients.
Methods: From November 2004 to December 2005, all patients aged greater than or equal to
65 years consecutively admitted to the Geriatric Unit of the Casa Sollievo della Sofferenza
Hospital, San Giovanni Rotondo in Italy, were evaluated for enrolment in the study. ADRs
were defined according to the WHO Adverse Reaction Terminology system. Drugs were
classified according to Anatomical Therapeutic Chemical classification system. The Naranjo
algorithm was used to evaluate the relationship between drug use and the ADR (definite,
probable, possible or doubtful) and Hallas criteria were used to evaluate the avoidability of the
ADR (definitely avoidable, possibly avoidable or unavoidable). All cases of a suspected ADR
were discussed by a team trained in drug safety, including three geriatricians, one clinical
pharmacologist and one pharmacist. Only cases of an ADR with an agreement greater than
or equal to 80% were included.
Results: Of the 1756 patients observed, 102 (5.8%, 42 males, 60 females, mean age 76.5 +/7.4 years, range 65-93 years) showed certain (6.8%) or probable (91.2%) ADR-related
hospitalisation. Gastrointestinal disorders (48 patients, 47.1%); platelet, bleeding and clotting
disorders (20 patients, 19.6%); and cardiovascular disorders (13 patients, 12.7%) were the
most frequent ADRs. NSAIDs (23.5%), oral anticoagulants (20.6%), low-dose aspirin
(acetylsalicylic acid) [13.7%] and digoxin (12.7%) were the drugs most frequently involved in
ADRs. Of the ADRs, 45.1% were defined as definitely avoidable, 31.4% as possibly
avoidable, 18.6% as unavoidable and 4.9% as unclassifiable. Of 78 patients with definitely or
possibly avoidable ADRs, 17 patients (21.8%) had received an inappropriate prescription, 29
patients (37.2%) had not received a prescription for an effective gastroprotective drug
concomitantly with NSAID or low-dose aspirin treatment and 32 patients (41%) were not
monitored during drug treatment.
Conclusions: In the elderly, almost 6% of hospitalizations are ADR related. Most of these
ADRs are potentially avoidable. Strategies that reduce inappropriate prescriptions and
monitoring errors, as well as improving active prevention of ADRs, are needed in elderly
subjects. (49 refs.)
http://adisonline.com/drugsafety/Abstract/2008/31060/Prevalence,_Clinical_Features_and_Av
oidability_of.9.aspx
14) Medication-related problems which cause admission to hospital
Original title: Problemas relacionados con la medicación que causan ingresos hospitalarios
JM Sotoca Momblona, S Canivell Fuste, L Alemany Vilches, et al.
Atencion Primaria, Mar 2009, vol. 41, no. 3, p. 141-146
Retrospective, observational and descriptive study at Les Corts Health Centre (HC), which is
an urban health and teaching centre with a reference population of 32,318 inhabitants,
including users of the les Corts HC, Barcelona, Spain, admitted to the Barcelona hospital from
Aug 2005 to Jan 2006. A pharmacist and a family doctor analysed the clinical histories and
determined whether or not there was a drug-related problem (DRP). A DRP was present in
13.4% of all hospital discharges, and DRPs were implicated (wholly or partially) in 12% of
hospital admissions. It was considered that 57.3% of all the discharges with a DRP as the
causing factor in the hospital admission were avoidable. Admissions due to DRP were mainly
in internal medicine, cardiology and pneumology. The health problems that lead to hospital
admission due to DRP are mainly circulatory (38.5%) and respiratory (11.5%). Concludes that
the number of hospital admissions due to drug-related problems is avoidably high.
http://www.elsevier.es/es/revistas/atencion-primaria-27/problemas-relacionados-medicacionque-causan-ingresos-hospitalarios-13135902-originales-2009
15) Emergency re-admissions to hospital due to adverse drug reactions within 1
year of the index admission
EC Davies, CF Green, DR Mottram, PH Rowe, M Pirmohamed
British Journal of Clinical Pharmacology Nov 2010;70(5):749-755
Aim: The proportion of re-admissions to hospital caused by ADRs is poorly documented in
the UK. The aim of this study was to evaluate the impact of ADRs on re-admission to hospital
after a period as an inpatient.
Methods: 1000 patients consecutively admitted to 12 wards were included. All subsequent
admissions for this cohort within 1 year of discharge from the index admission were
retrospectively reviewed.
Results: Of the 1000 patients included, 403 (40.3%; 95% CI, 39.1, 45.4%) were re-admitted
within 1 year. Complete data were available for 290 (70.2%) re-admitted patients, with an
ADR contributing to admission in 60 (20.8%; 95% CI, 16.4, 25.6%) patients. Presence of an
ADR in the index admission did not predict for an ADR-related re-admission (10.5% vs 7.2%;
P = 0.25) or re-admission overall (47.2% vs 41.2%; P = 0.15). The implicated drug was
commenced in the index admission in 33/148 (22.3%) instances, with 37/148 (25%)
commenced elsewhere since the index admission. Increasing age and an index admission in
a medical ward were associated with a higher incidence of re-admission ADR. The most
frequent causative drugs were anti-platelets and loop diuretics, with bleeding and renal
impairment the most frequent ADRs. Over half (52/91, 57.1%) of the ADRs were judged to be
definitely or possibly avoidable.
Conclusions: One-fifth of patients re-admitted to hospital within 1 year of discharge from
their index admission are re-admitted due to an ADR. Our data highlight drug and patient
groups where interventions are needed to reduce the incidence of ADRs leading to readmission.
Note: This paper was originally presented in the pharmacy practice session of the British
Pharmaceutical Conference, Manchester, 6-7 Sep 2009. Paper No. 18. See: International
Journal of Pharmacy Practice, Sep 2009, vol. 17, no. Suppl.2, p. B17-B18
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2125.2010.03751.x/abstract
16) Impact of the Lund Integrated Medicines Management (LIMM) model on
medication appropriateness and drug-related hospital revisits
LM Hellstrom, A Bondesson, P Hoglund, P Midlov, L Holmdahl, E Rickhag, T Eriksson
European Journal of Clinical Pharmacology Jul 2011;67(7):741-752
Purpose: To examine the impact of systematic medication reconciliations upon hospital
admission and of a medication review while in hospital on the number of inappropriate
medications and unscheduled drug-related hospital revisits in elderly patients.
Methods: This was a prospective, controlled study in 210 patients, aged 65 years or older,
who were admitted to one of three internal medicine wards at a University Hospital in
Sweden. Intervention patients received the complete Lund Integrated Medicines
Management model (medication reconciliation upon admission and discharge, and
medication review and monitoring) provided by a multi-professional team, including a clinical
pharmacist. Control patients received standard care and medication reconciliation upon
discharge. Blinded reviewers evaluated the appropriateness of the prescribing (using the
Medication Appropriateness Index) on admission and discharge, and assessed the probability
that a drug-related problem was the reason for any patient readmitted to hospital or visiting
the emergency department within 3 months of discharge (using World Health Organisation
causality criteria).
Results: There was a greater decrease in the number of inappropriate drugs in the
intervention group than in the control group for both the intention-to-treat population {51%;
95% CI, 43-58% vs 39%; 95% CI, 30-48%); p = 0.0446} and the per-protocol population
(60%; 95% CI, 51-67% vs 44%; 95% CI; 34-52%; p = 0.0106). There were 6 revisits to
hospital in the intervention group which were judged as 'possibly, probably or certainly drugrelated', compared with 12 in the control group (p = 0.0469).
Conclusions: In this study, medication reconciliation and review provided by a clinical
pharmacist in a multi-professional team significantly reduced the number of inappropriate
drugs and unscheduled drug-related hospital revisits among elderly patients.
http://www.springerlink.com/content/286840426v0pwq37/
17) Causes of preventable drug-related hospital admissions: a qualitative study
R Howard, A Avery, P Bissell
Quality and Safety in Health Care, Apr 2008, vol. 17, no. 2, p. 109-116
The causes of preventable drug-related admissions (PDRAs) to hospital in Nottingham were
examined in qualitative case studies using semi-structured interviews and medical record
review; data were analysed using a framework derived from Reason's model of organisational
accidents and cascade analysis. There were 62 participants, including 18 patients, 8 informal
carers, 17 general practitioners, 12 community pharmacists, 3 practice nurses and 4 other
members of healthcare staff, involved in events leading up to the patients' hospital
admissions. PDRAs were found to be associated with problems at multiple stages in the
medication use process, including prescribing, dispensing, administration, monitoring and
help seeking. The main causes of these problems are communication failures (between
patients and healthcare professionals and different groups of healthcare professionals) and
knowledge gaps (about drugs and patients' medical and medication histories). The causes of
PDRAs are similar irrespective of whether the hospital admission is associated with a
prescribing, monitoring or patient adherence problem. Concludes that the causes of PDRAs
are multifaceted and complex. Technical solutions to PDRAs will need to take account of this
complexity and are unlikely to be sufficient on their own. Interventions targeting the human
causes of PDRAs are also necessary - for example, improving methods of communication.
http://qualitysafety.bmj.com/content/17/2/109.abstract