Hospitalisations caused by adverse drug reactions (ADR): a meta-analysis of observational studies

Comprehensive discharge follow-up in patients' homes by GPs and district nurses of elderly patients. A randomized controlled trial

OBJECTIVES

Many hospital admissions are due to inappropriate medical treatment, and discharge of fragile elderly patients involves a high risk of readmission. The present study aimed to assess whether a follow-up programme undertaken by GPs and district nurses could improve the quality of the medical treatment and reduce the risk of readmission of elderly newly discharged patients.

DESIGN AND SETTING

The patients were randomized to either an intervention group receiving a structured home visit by the GP and the district nurse one week after discharge followed by two contacts after three and eight weeks, or to a control group receiving the usual care.

PATIENTS

A total of 331 patients aged 78+ years discharged from Glostrup Hospital, Denmark, were included.

MAIN OUTCOME MEASURES

Readmission rate within 26 weeks after discharge among all randomized patients. Control of medication, evaluated 12 weeks after discharge on 293 (89%) of the patients by an interview at home and by a questionnaire to the GP.

RESULTS

Control-group patients were more likely to be readmitted than intervention-group patients (52% v 40%; p = 0.03). In the intervention group, the proportions of patients who used prescribed medication of which the GP was unaware (48% vs. 34%; p = 0.02) and who did not take the medication prescribed by the GP (39% vs. 28%; p = 0.05) were smaller than in the control group.

CONCLUSION

The intervention shows a possible framework securing the follow-up on elderly patients after discharge by reducing the readmission risk and improving medication control.

Competition in general practice: prescriptions to the elderly in a list patient system

Income motivation among general practitioners (GPs) is frequently discussed in the health economics literature. The question addressed in the present study on reimbursement drugs and addictive drugs is whether increased competition among GPs, which is part of a declared health policy to improve efficiency, contributes to more prescriptions for the elderly. The dataset comprises registered data of all prescribed drugs dispensed at pharmacies from the Norwegian Prescription Database merged with data on GPs. In choosing a method, particular attention is given to the fact that patients tend to be attracted to GPs who fit their preferences. Hence, we treat the composition of the patient list as endogenous. The results indicate that the stronger competition a GP faces, the more drugs are prescribed, which implies that GPs' prescription style may conflict with their role as gatekeepers, and even worse, it may be a hazard to patients' health.

Medication and falls: risk and optimization

The association between drugs and falls has been widely studied in the past 3 decades, with increasingly robust evidence of a causal link. Both specific classes of drugs and the total number of drugs taken are associated with falls. This review examines some of the reasons why older people are at greater risk of drug-related adverse events such as falls. We discuss the role of drugs in general and polypharmacy (the concurrent use of multiple drugs) on the risk of falling, with a focus on community-dwelling older people. We critically appraise the evidence that specific classes of drugs, such as benzodiazepines and antidepressants, increase the risk of falling and that falls can be prevented through interventions that target medications.

Adverse drug reactions in older people

Adverse drug reactions (ADR) pose significant health-related problems for the older person. Many studies from around the world report a significant incidence of ADR in general and in elderly people in particular, resulting in an increase in drug-related morbidity and mortality. Older people appear to be particularly at risk of experiencing an ADR due to a range of factors, which include polypharmacy, altered drug pharmacokinetic profiles and pharmacodynamic responses, drug interactions and cognitive problems that increase the risk in this patient group. Certain drug classes, such as hypoglycaemic agents and cardiovascular active medicines, have been identified as common causes of ADR. Many studies suggest that the majority of ADR are preventable, so that several different approaches have been tried in an attempt to limit this problem, such as the use of computerized systems to communicate routine issues of patient care, interventions made by pharmacists, spontaneous reporting and continuous education of health care professionals. Whilst all have been shown to reduce drug-related events, identifying individuals at high risk of developing ADR at the point of prescribing by using a risk stratification model could improve the identification and prevention of ADR. This article discusses the clinical impact of ADR in older people and the relative merits of the various approaches tested to date before suggesting areas that require further research.

Contribution of drug related problems to hospital admission in the elderly

PURPOSE

To investigate the frequency and type of drug related problems (DRPs) in geriatric patients (> 65 years), and to assess their contribution to hospital admission; to explore the appropriateness of drug therapy according to the Beers' criteria.

METHODS

Cross-sectional observational survey of 110 elderly patients admitted during three non-consecutive months to the geriatric ward of a university hospital. Explorative assessment of appropriateness of drug therapy prior to hospital admission based on the Beers' criteria.

RESULTS

A DRP was the dominant reason for hospital admission in 14 out of the 110 patients (12.7%); for another 9 patients (8.2%), a DRP was partly contributing to hospital admission. For these 23 patients, adverse drug reactions and noncompliance were the most important types of DRPs. We found no relationship between drug related hospital admission and intake of a drug listed in the Beers criteria for inappropriate drug use in the elderly. Patients admitted for a DRP took more drugs before admission than patients admitted because of other reasons.

CONCLUSIONS

DRPs are an important cause for admission on the geriatric ward of our hospital. The drugs causing DRPs in this study were not those listed in the Beers list of inappropriate drugs in the elderly.

Patient focused drug surveillance of elderly patients in nursing homes

PURPOSE

To examine whether patient focused drug surveillance was associated with a higher quality of drug treatment at nursing homes.

METHODS

An intervention study in four nursing homes in Sweden and four other nursing homes served as controls. At the intervention nursing homes physicians focused on patients' health status as a baseline for further ongoing medication. The outcomes were mortality, health care consumption, and number of drugs, health status and evaluations as parameters for "quality of drug treatment".

RESULTS

There were no significant differences in mortality rates. Health care consumption and polypharmacy were extensive in both groups. There was a significant reduction of number of drugs used per patient at the intervention homes during the study (p < 0.05). Monitoring and evaluation of the effects of medications were significantly more frequent at the intervention homes (p < 0.01).

CONCLUSIONS

The intervention resulted in significant positive results in relation to "quality of drug treatment", a shift in health care utilization with concomitant use of fewer drugs. The study showed an extreme shortage of monitoring of health status and surveillance of the effects of drugs in the elderly.

Prevalence and safety-relevance of drug-related problems in German community pharmacies

PURPOSE

The purpose of this study was to assess prevalence and characteristics, including safety-relevance, of drug-related problems (DRPs) detectable in community pharmacy routine service, and to investigate the influence of relevant risk factors.

METHODS

Patients in 69 community pharmacies in Berlin were surveyed using a checklist for quality assurance of DRP detection in order to enable quantitative detection. An expert committee assessed the safety-relevance of detected DRPs by use of an algorithm. Logistic regression analysis was applied to investigate the influence of different risk factors.

RESULTS

Of the 3040 surveyed patients, 638 (21.0%) were affected by DRPs. Among these, 455 (71.3%) had problems of low, 170 (26.6%) of significant and 13 (2.0%) of high safety-relevance. Significant risk factors identified were self-medication and new medication, especially new prescriptions. Age, gender and the number of dispensed drugs had little influence on occurrence of DRPs. The two major groups of DRPs were therapeutic errors, often correlating with self-medication, and information problems, often correlating with new medications. Drug classes most frequently associated with DRPs were analgesics/NSAID, antibiotics, nasal preparations and cough medications.

CONCLUSION

DRPs are frequent among patients in German community pharmacies. Advanced research in this field (DRP-pharmacovigilance) and implementation of methods for quality assurance of pharmaceutical counselling, that is exhaustive DRP detection, may improve the safety of drug therapies significantly. In particular, pharmaceutical counselling is an important instrument for assuring treatment appropriateness and safety of OTC drugs.

Drug treatment in an ageing population: practical implications

The population of the industrialised nations is ageing. By 2020 those of 65 years and older will constitute nearly 17% of the US population; it is predicted that the proportion of the population aged 80 years and over will then range from 3.5 to 6.5%, around the world. Those over 65, due to age-related chronic disease and more prophylactic prescribing, receive a disproportionate number of drugs; in the UK for example, 45% of the total prescriptions dispensed. Older patients may benefit from prophylactic treatments to a greater extent than younger people because of a higher absolute risk of disease and it is therefore important that they are not inappropriately denied these. However, it is also important that, as each additional drug prescribed brings an increased risk of an adverse drug effect, prescribers have enough knowledge of pharmacological issues in old age to enable them to weigh up these conflicting pressures to arrive at good prescribing decisions.

The pathophysiology of medication errors: how and where they arise

1. Errors arise when an action is intended but not performed; errors that arise from poor planning or inadequate knowledge are characterized as mistakes; those that arise from imperfect execution of well-formulated plans are called slips when an erroneous act is committed and lapses when a correct act is omitted. 2. Some tasks are intrinsically prone to error. Examples are tasks that are unfamiliar to the operator or performed under pressure. Tasks that require the calculation of a dosage or dilution are especially susceptible to error. 3. The tasks of prescribing, preparation, and administration of medicines are complex, and are carried out within a complex system; errors can occur at each of many steps and the error rate for the overall process is therefore high. 4. The error rate increases when health-care professionals are inexperienced, inattentive, rushed, distracted, fatigued, or depressed; orthopaedic surgeons and nurses may be more likely than other health-care professionals to make medication errors. 5. Medication error rates in hospital are higher in paediatric departments and intensive care units than elsewhere. 6. Rates of medication errors may be higher in very young or very old patients. 7. Intravenous antibiotics are the drugs most commonly involved in medication errors in hospital; antiplatelet agents, diuretics, and non-steroidal anti-inflammatory drugs are most likely to account for 'preventable admissions'. 8. Computers effectively reduce the rates of easily counted errors. It is not clear whether they can save lives lost through rare but dangerous errors in the medication process.

Prospective randomized double-blind trial of racecadotril compared with loperamide in elderly people with gastroenteritis living in nursing homes

AIM

Our aim was to compare the efficacy and tolerability of loperamide and racecadotril in elderly patients with acute diarrhea.

RESEARCH DESIGN AND METHODS

We performed a randomized, prospective, double-blind, and parallel group design implemented in geriatric nursing homes in Catanzaro, Italy, from February 2008 to March 2009. Patients of both sexes were randomly allocated to receive either one tablet of racecadotril 100 mg every 8 h or two tablets of loperamide 2.0 mg followed by one tablet after each unformed stool, up to four tablets in any 24-h period. Patients were treated until recovery, defined as the production of two consecutive normal stools or no stool production for a period of 12 h.

RESULTS

Normal stools were collected 36 +/- 4 h after the beginning of racecadotril and in 63 +/- 6 h from the beginning of loperamide administration (P < 0.01). The median time of abdominal pain in the intent-to-treat (ITT) population was 14 h for racecadotril and 28 h for loperamide. In the per-protocol (PP) population, the median time of abdominal pain was 14 h for racecadotril and 32 h for loperamide (P < 0.01). About the 50% of patients experienced at least one adverse event during the study: 12% in the racecadotril group and 60% in the loperamide group. The most frequently occurring adverse events were nausea and constipation. Genetic analysis did not report the presence of rapid or poor metabolizers. Pharmacoeconomic analysis performed at the end of our study documented an increase in costs in the loperamide group with respect to the racecadotril group (P < 0.01).

CONCLUSIONS

Racecadotril is more effective than loperamide-probably due to drug interaction with loperamide-and it is not related to pharmacogenetic susceptibility. Racecadotril is also more cost effective than loperamide.

GPs' perceptions of multiple-medicine use in older patients

RATIONALE, AIM AND OBJECTIVE

Multiple-medicine use (polypharmacy) is a growing problem for older patients, prescribers and health policy makers. The general practitioner (GP) is most often the main professional care provider; hence, improvements of treatment can only be carried out in concordance with GPs. The aim of this study was, therefore, to explore GPs' perspectives of treating older users of multiple medicines, using a qualitative approach.

METHOD

Six focus groups, with four private GPs and 27 county-employed GPs, were analysed by using the framework method.

RESULTS

In contrast to definitions in most epidemiologic studies, the GPs gave a spontaneous definition of polypharmacy as 'the administration of more medicines than are clinically indicated'. They had problems stating both a cut-off number and which medicines should be included. Clinical practice guidelines were thought of as 'medicine generators', having an ambiguous effect on the GPs, who both trust them and find them difficult to apply. There was a perceived lack of communication between GPs and hospital specialists concerning their patients' medicines, which was further perceived to reduce treatment quality. The influence of patient pressure was acknowledged by the GPs as a factor contributing to the development of multiple-medicine use.

CONCLUSIONS

The GPs felt insecure although surrounded by clinical practice guidelines. There is a need for policy makers to appreciate this paradox, as the problem is likely to grow in size and proportion. GPs must be empowered to handle the increasing proportion of older users of multiple medicines with individual agendas, receiving care from multiple specialists.

Nurse-led medication reviews and the quality of drug treatment of elderly hospitalized patients

PURPOSE

To evaluate if nurses after receiving training in clinical pharmacology can improve the quality of the drug therapy in elderly hospitalized patients.

METHODS

Nurses were given a 1-day training in clinical pharmacology to identify drug-related problems (DRPs).All patients admitted to the ward aged 65 or more were studied. Patients at the same ward before the intervention were considered as control group. Outcome variables were re-hospitalized 3 months from discharge, drug-related readmissions, the proportion of inappropriate drug use (IDU), and DRPs found by the nurses.

RESULTS

Of 460 patients (250 intervention group and 210 in the control group) 38 and 36%, respectively, had at least one re-admission to hospital (p=0.86) and 24% of the patients died. Eighteen and 17% (43/37), respectively, used one or more inappropriate drug (p 0.90). The nurses found 86 clinically significant DRPs not detected by the usual care. A substantial part of the DRPs detected by the nurses were revealed with assistance of Symptoms Assessment Form (SYM). There were no statistical difference in the number of drug-related re-admissions between the groups, 14/16, respectively, (p=0.40).

CONCLUSIONS

Nurses are able to detect a high proportion of clinically relevant DRPs not detected by the usual care and thereby increase the quality of the drug treatment in elderly hospitalized patients. Our study showed no effect on re-hospitalization or IDU. By using a SYM nurses can find DRPs that computer-based decision support systems miss.

Depressive effect of an antidepressant: therapeutic failure of venlafaxine in a case lacking CYP2D6 activity

Understanding the mechanisms of drug metabolism and interactions can help to prevent side-effects. Not only drug interactions, environmental factors, disease processes and ageing are factors in the inter-individual metabolic capacity variance but also genetic factors probably play an important role, as is illustrated in the case presented. Besides therapeutic drug monitoring, genotyping some important cytochrome P450 (CYP450) enzymes was of additional value in explaining why the patient developed severe adverse effects and, moreover, did not experience any therapeutical effect of venlafaxine. Results indicated that the patient was a poor metabolizer for CYP2D6, the most important phase I enzyme to metabolize venlafaxine. This corroborates that polymorphisms in the CYP450 gene influence the metabolic activity of the corresponding enzymes, thus affecting the subsequent serum drug levels and their metabolites. This case highlights the potential benefit of both clinical and genetic risk stratification (pharmacogenetics) prior to treatment, either for setting the individual dose or for making a decision about using a particular drug.

Continuing education course to attain collaborative comprehensive medication review competencies

OBJECTIVE

To implement a long-term continuing education course for pharmacy practitioners to acquire competency in and accreditation for conducting collaborative comprehensive medication reviews (CMRs).

DESIGN

A 1(1/2)- year curriculum for practicing pharmacists that combined distance learning (using e-learning tools) and face-to-face learning was created. The training consisted of 5 modules: (1) Multidisciplinary Collaboration; (2) Clinical Pharmacy and Pharmacotherapy; (3) Rational Pharmacotherapy; (4) CMR Tools; and (5) Optional Studies.

ASSESSMENT

The curriculum and participants' learning were evaluated using essays and learning diaries. At the end of the course, students submitted portfolios and completed an Internet-based survey instrument. Almost all respondents (92%) indicated their educational needs had been met by the course and 68% indicated they would conduct CMRs in their practice. The most important factors facilitating learning were working with peers and in small groups. Factors preventing learning were mostly related to time constraints.

CONCLUSION

Comprehensive medication review competencies were established by a 1(1/2)- year continuing education curriculum that combined different teaching methods and experiential learning. Peer support was greatly appreciated as a facilitator of learning by course participants.

A multi-intervention approach on drug therapy can lead to a more appropriate drug use in the elderly. LIMM-Landskrona Integrated Medicines Management

RATIONALE, AIMS AND OBJECTIVES

To evaluate if an integrated medicines management can lead to a more appropriate drug use in elderly inpatients.

METHOD

The study was an intervention study at a department of internal medicine in southern Sweden. During the intervention period pharmacists took part in the daily work at the wards. Systematic interventions aiming to identify, solve and prevent drug-related problems (DRPs) were performed during the patient's hospital stay by multidisciplinary teams consisting of physicians, nurses and pharmacists. DRPs identified by the pharmacist were put forward to the care team and discussed. Medication Appropriateness Index (MAI) was used to evaluate the appropriateness in the patients' drug treatment at admission, discharge and 2 weeks after discharge. In total 43 patients were included, 28 patients in the intervention group and 25 patients in the group which was used as control.

RESULTS

For the intervention group there was a significant decrease in the number of inappropriate drugs compared with the control group (P = 0.049). Indication, duration and expenses were the MAI-dimensions with most inappropriate ratings, and the drugs with most inappropriate ratings were anxiolytics, hypnotics and sedatives.

CONCLUSION

This kind of systematic approach on drug therapy can result in a more appropriate drug use in the elderly.

Application of STOPP and START criteria: interrater reliability among pharmacists

BACKGROUND

Inappropriate prescribing is a well-documented problem in older people. The new screening tools, STOPP (Screening Tool of Older Peoples' Prescriptions) and START (Screening Tool to Alert doctors to Right Treatment) have been formulated to identify potentially inappropriate medications (PIMs) and potential errors of omissions (PEOs) in older patients. Consistent, reliable application of STOPP and START is essential for the screening tools to be used effectively by pharmacists.

OBJECTIVE

To determine the interrater reliability among a group of clinical pharmacists in applying the STOPP and START criteria to elderly patients' records.

METHODS

Ten pharmacists (5 hospital pharmacists, 5 community pharmacists) were given 20 patient profiles containing details including the patients' age and sex, current medications, current diagnoses, relevant medical histories, biochemical data, and estimated glomerular filtration rate. Each pharmacist applied the STOPP and START criteria to each patient record. The PIMs and PEOs identified by each pharmacist were compared with those of 2 academic pharmacists who were highly familiar with the application of STOPP and START. An interrater reliability analysis using the kappa statistic (chance corrected measure of agreement) was performed to determine consistency between pharmacists.

RESULTS

The median kappa coefficients for hospital pharmacists and community pharmacists compared with the academic pharmacists for STOPP were 0.89 and 0.88, respectively, while those for START were 0.91 and 0.90, respectively.

CONCLUSIONS

Interrater reliability of STOPP and START tools between pharmacists working in different sectors is good. Pharmacists working in both hospitals and in the community can use STOPP and START reliably during their everyday practice to identify PIMs and PEOs in older patients.

The frequency of adverse drug reaction related admissions according to method of detection, admission urgency and medical department specialty

BACKGROUND

Adverse Drug Reactions (ADRs) have been regarded as a major public health problem since they represent a sizable percentage of admissions. Unfortunately, there is a wide variation of ADR related admissions among different studies. The aim of this study was to evaluate the frequency of ADR related admissions and its dependency on reporting and method of detection, urgency of admissions and included medical departments reflecting department/hospital type within one study.

METHODS

The study team of internal medicine specialists retrospectively reviewed 520 randomly selected medical records (3%) of patients treated in the medical departments of the primary city and tertiary referral governmental hospital for certain ADRs causing admissions regarding WHO causality criteria. All medical records were checked for whether the treating physicians recognised and documented ADRs causing admissions. The hospital information system was checked to ensure ADR related diagnoses were properly coded and the database of a national spontaneous reporting system was searched for patients with ADRs included in this study.

RESULTS

The established frequency of admissions due to certain ADRs recognised by the study team and documented in medical records by the treating physicians was the same and represented 5.8% of all patients (30/520). The frequency of ADR causing admissions detected by employing a computer-assisted approach using an ICD-10 coding system was 0.2% (1/520), and no patient admitted due to ADRs was reported to the national reporting system (0/520). The recognized frequency of ADR related admissions also depends on the department's specialty (p = 0.001) and acceptance of urgently admitted patients (p = 0.001). Patients admitted due to ADRs were significantly older compared to patients without ADRs (p = 0.025). Gastrointestinal bleeding due to NSAID, acetylsalicylic acid and warfarin was the most common ADR that resulted in admission and represented 40% of all certain ADRs (12/30) according to WHO causality criteria.

CONCLUSION

ADRs cause 5.8% of admissions in medical departments in the primary city and tertiary referral hospital. The physicians recognise certain ADR related admissions according to WHO causality criteria and note them in medical records, but they rarely code and report ADRs. The established frequency of ADR related admissions depends on the detection method, department specialty and frequency of urgently admitted patients.

Contribuição do uso de medicamentos para a admissão hospitalar

As Reações Adversas a Medicamentos (RAM) podem ser responsáveis por 2,4% a 11,5% das admissões hospitalares. O estudo objetivou conhecer o perfil demográfico dos pacientes internados por possíveis RAM, identificar os medicamentos e as queixas mais freqüentemente relacionadas e estimar a incidência de admissão hospitalar pelo uso de medicamentos. Durante um mês, os pacientes internados em um hospital geral foram entrevistados quanto ao uso de medicamentos antes da internação e as queixas que o levaram ao hospital; as informações foram analisadas, usando-se a base de dados MICROMEDEX® e outras bases oficiais. Observou-se que as admissões por uso de medicamentos ocorreram predominantemente em idosos [47,5% (66/139)] e mulheres [62% (87/139)]. Os medicamentos mais freqüentes foram: omeprazol (16), analgésicos (31), antihipertensivos (31), sinvastatina (7) e formoterol (6); e normalmente os sintomas associados foram do sistema digestório (20,5%), circulatório (20,2%), respiratório (18,2%) e SNC (13,9%). Estima-se que em 15,5% (139/897) das internações, possivelmente, a razão foi o uso de medicamentos. Os dados sugerem medidas de prevenção, como o acompanhamento farmacoterapêutico dos pacientes no âmbito da assistência primária à saúde, principalmente aos idosos, aos portadores de doenças crônicas e aos polimedicados, além da orientação farmacêutica na compra e dispensação de medicamentos, principalmente os isentos de prescrição.

Promoting Appropriate Drug Use Through the Application of the Spanish Drug-Related Problem Classification System in the Primary Care Setting

Background:

According to the Second Consensus of Granada (2002), the term drug-related problem (DRP) is defined as a health problem resulting from pharmacotherapy and is considered a negative clinical outcome (ie, a therapeutic objective is not achieved or adverse effects are reported). DRP classification systems used in primary care settings can be useful tools to detect, evaluate, and resolve DRPs.

Objective:

To encourage appropriate drug use in the ambulatory clinical setting through DRP detection and evaluation by means of the Spanish DRP classification system, and to document how pharmacists can help resolve DRPs through interventions with both general practitioners (GPs) and patients.

Methods:

Four pharmacists investigated DRPs in polymedicated patients over a 6-month period. All detected DRPs were grouped into 3 major categories: necessity, effectiveness, and safety. To resolve DRPs, pharmacists performed interventions on GPs and patients. GPs received verbal and written information about DRPs; patient interventions were in the form of private meetings on health education.

Results:

Four hundred twenty-two patients, 80% of whom were aged 65 years or older, were included in the study. Each patient was taking a mean ± SD of 8.1 ± 2.4 medications. Three hundred four medications were associated with 245 DRPs; medications indicated for digestive/metabolic or cardiovascular pathologies were the most prevalent. Most (60%) of the identified DRPs belonged to the effectiveness category, whereas safety issues accounted for 28.6%. The most frequently reported DRP was pathology resistant to treatment (19.6%), followed by nonadherence (16.3%). Of the 215 interventions carried out to resolve these DRPs, 173 (80.5%) were addressed to GPs, who agreed to change therapy regimens on 90.2% of the occasions. Forty-two (19.5%) interventions were addressed to patients. Furthermore, the interventions accepted by GPs and patients resolved 176 (82%) DRPs.

Conclusions:

The current Spanish DRP classification system is a useful tool to systematically detect and document DRPs in daily general practice, in addition, the interventions addressed by pharmacists to GPs and patients resolved most of the detected DRPs.

Comorbidity and repeat admission to hospital for adverse drug reactions in older adults: retrospective cohort study

OBJECTIVES

To identify factors that predict repeat admission to hospital for adverse drug reactions (ADRs) in older adults.

DESIGN

Population based retrospective cohort study.

SETTING

All public and private hospitals in Western Australia.

PARTICIPANTS

28 548 patients aged >or=60 years with an admission for an ADR during 1980-2000 followed for three years using the Western Australian data linkage system.

RESULTS

5056 (17.7%) patients had a repeat admission for an ADR. Repeat ADRs were associated with sex (hazard ratio 1.08, 95% confidence interval 1.02 to 1.15, for men), first admission in 1995-9 (2.34, 2.00 to 2.73), length of hospital stay (1.11, 1.05 to 1.18, for stays >or=14 days), and Charlson comorbidity index (1.71, 1.46 to 1.99, for score >or=7); 60% of comorbidities were recorded and taken into account in analysis. In contrast, advancing age had no effect on repeat ADRs. Comorbid congestive cardiac failure (1.56, 1.43 to 1.71), peripheral vascular disease (1.27, 1.09 to 1.48), chronic pulmonary disease (1.61, 1.45 to 1.79), rheumatological disease (1.65, 1.41 to 1.92), mild liver disease (1.48, 1.05 to 2.07), moderate to severe liver disease (1.85, 1.18 to 2.92), moderate diabetes (1.18, 1.07 to 1.30), diabetes with chronic complications (1.91, 1.65 to 2.22), renal disease (1.93, 1.71 to 2.17), any malignancy including lymphoma and leukaemia (1.87, 1.68 to 2.09), and metastatic solid tumours (2.25, 1.92 to 2.64) were strong predictive factors. Comorbidities requiring continuing care predicted a reduced likelihood of repeat hospital admissions for ADRs (cerebrovascular disease 0.85, 0.73 to 0.98; dementia 0.62, 0.49 to 0.78; paraplegia 0.73, 0.59 to 0.89).

CONCLUSIONS

Comorbidity, but not advancing age, predicts repeat admission for ADRs in older adults, especially those with comorbidities often managed in the community. Awareness of these predictors can help clinicians to identify which older adults are at greater risk of admission for ADRs and, therefore, who might benefit from closer monitoring.

Prevalence, clinical features and avoidability of adverse drug reactions as cause of admission to a geriatric unit: a prospective study of 1756 patients

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 >or=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 >or=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 hospitalization. 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.

CONCLUSION

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.

Prevalence of adverse drug combinations in a large post-mortem toxicology database

The prevalence of important adverse drug combinations was studied among the 37,367 cases included in the Finnish post-mortem toxicology database during 2000-2006. The new SFINX interaction database (Swedish, Finnish, INteraction X-referencing) was utilised to identify adverse drug combinations. Consequently, the 24 drugs chosen for the study generated 96 two-compound combinations possessing potentially severe interactions. The total number of hits for the combinations found in the post-mortem database was 267, which accounts for approximately 0.71% of all cases. The potential role of adverse drug interaction (ADI) in these cases was evaluated from the background information and death certificate. The possible ADI cases comprised 23% of all hits and 0.17% of all cases analysed. In cases with a pharmacodynamic mechanism, the most prominent combinations were medicines causing serotonin syndrome or a beta(1)-blocker with verapamil or diltiazem. In cases with a pharmacokinetic mechanism, half of the cases involved digoxin in combination with verapamil. In one third of the possible ADI cases, a forensic pathologist had noted the studied compounds as an underlying or contributing cause of death, although the agents' specific role in ADIs was rarely recognised.

Hospital Admissions Associated with Adverse Drug Reactions: A Systematic Review of Prospective Observational Studies

Objective:

To determine the prevalence of hospital admissions associated with ADRs and examine differences in prevalence rates between population groups and methods of ADR detection.

Data Sources:

Studies were identified through electronic searches of Cumulative Index to Nursing and Allied Hearth Literature. EMBASE, and MEDLINE to August 2007. There were no language restrictions.

Study Selection and Data Extraction:

A systematic review was conducted of prospective observational studies that used the World Health Organization ADR definition. Subgroup analysis examined the influence of patient age groups and methods of ADR detection on reported ADR admission rates. All statistical analyses were performed using STATA v 9.0.

Data Synthesis:

Twenty-five studies were identified including 106, 586 patients who were hospitalized; 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% (interquartile range [IQR] 2.7–9.0%). Median ADR prevalence rates varied between age groups: for children, the ADR admission rate was 4.1% (IQR 0.16–5.3%), while the corresponding rates for adults and elderly patients were 6.3% (IQR 3.9–9.0%) and 10.7% (IQR 9.6–13.3%), respectively. ADR rates also varied depending on the methods of ADR detection employed in the different studies. Studies that employed multiple ADR detection methods, such as medical record review and patient interview, reported higher ADR admission rates compared with studies that used medical record review alone. Antiinfective drugs were most often associated with ADR admissions in children; cardiovascular drugs were most often associated with ADR admissions in adults and elderly patients.

Conclusions:

Approximately 5.3% of hospital admissions were associated with ADRs. 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.

Adverse drug reaction-related hospitalisations: a population-based cohort study

PURPOSE

To evaluate the extent, characteristics and determinants of adverse drug reaction (ADR)-related hospitalisations on a population-based level in 2003.

METHODS

We performed a cohort study in the Integrated Primary Care Information (IPCI) database, a general practitioners (GPs) research database with longitudinal data from electronic patient records of a group of 150 GP throughout the Netherlands. Hospital discharge letters and patient records were reviewed to evaluate ADR-related hospitalisations applying WHO causality criteria. The prevalence of ADR-related hospitalisations per total admissions and the incidence per drug group were calculated. Avoidability and seriousness of the ADRs causing admission were assessed applying the algorithm from Hallas.

RESULTS

We identified 3515 hospital admissions, 1277 elective and 2238 acute. Of the acute admissions, 115 were caused by an ADR giving a prevalence of 5.1% (95% confidence intervals (CI): 4.3-6.1%). The prevalence of ADR-related acute admissions increased with age up to 9.8% (95%CI: 7.5-12.7) for persons >75 years. The ADRs that most frequently caused hospitalisations were gastro-intestinal bleeding with anti-thrombotics, bradycardia/hypotension with cardiovascular drugs and neutropenic fever with cytostatics. The incidence rate of ADR-related hospitalisations per drug group was highest for anti-thrombotics and anti-infectives and was relatively low for cardiovascular drugs. Fatality as a direct consequence of the ADR-related admission was 0.31%. In elderly patients 40% of the ADRs causing hospitalisation were judged to be avoidable.

CONCLUSIONS

The extent and potential avoidability of ADR-related hospitalisations is still substantial, especially in elderly patients. Measures need to be put into place to reduce the burden of ADRs.

Indicators for preventable drug-related morbidity. Practical application in home-based care

AIM

The aim of this study is of evaluating Morris' PDRM indicator system in the Italian Health Care System, especially in the context of home-based health care assistance, so as to assess the reliability of such a system to detect preventable events of drug-related morbidity (DRM).

METHODS

This is a pilot study which has been carried out on a control group of patients. The results, which have been obtained, have then been used to calculate the incidence of the preventable drug-related morbidity (PDRM) in the entire population. The sample of patients was taken from the Health District of Chivasso (Local Health Unit 7 in Piedmont). The subjects had all been inserted in the Integrated Home Healthcare Assistance programme in the period from 1st January to 31st December 2004.

RESULTS

The PDRM is equal to 32, with an incidence of 15.6% in the entire population (205). Seven indicators out of 19 were able to identify PDRM. Of these, the indicator which showed the best detection rate scored 72%.

CONCLUSIONS

The study revealed that this indicator system has the capability of detecting events of PDRM. In addition to this, the version of the system which has been approved by the expert panel has proved executable in the Italian healthcare system, especially in home-based healthcare.

Adverse drug reactions related to hospital admission in Slovak elderly patients

The aims of the present study were: to evaluate the prevalence of adverse drug reactions (ADRs) leading to hospitalization in elderly patients; to analyze the drugs which have been identified as having causal relationship with ADRs and to identify risk factors which predispose the patient to such ADRs. The study has been performed in 600 patients aged> or =65 years, hospitalized in a general hospital between 1 December 2003 and 31 March 2005. The ADRs recorded in patient's documentation as one of the reasons for hospital admission were evaluated. ADRs leading to hospital admission were recorded in 47 (7.8%) patients. ADRs in 43 patients represented A-type ADRs which are preventable. The most frequent ADRs were cardiovascular disorders. According to the results of multivariate analysis ischemic heart disease (odds ratio (OR)=4.50; 95% confidence interval (CI)=1.36-14.88), depression (OR, 2.49; 95% CI, 1.08-5.77) and heart failure (OR, 2.08; 95% CI, 1.13-3.81) were the most important patient-related characteristics predicting ADRs leading to hospitalization. The majority of ADRs in elderly patients could be avoided. Regular re-evaluation of the medication as well as taking into account the specific features of elderly patients represent the most important tools for ADR prevention.

Pharmacologically inappropriate prescriptions for elderly patients in general practice: How common? Baseline data from The Prescription Peer Academic Detailing (Rx-PAD) study

OBJECTIVE

To assess Norwegian general practitioners' (GPs') level of potentially harmful drug prescribing for elderly patients.

DESIGN

Prescription data for 12 months were retrospectively retrieved from the Norwegian Prescription Database (NorPD). Data were assessed in relation to 13 prescription quality indicators.

SETTING

General practice.

SUBJECTS

A total of 454 GPs attending continuous medical education (CME) groups in Southern Norway, 85,836 patients >or=70 years who received any prescription from the GPs during the study period.

MAIN OUTCOME MEASURES

Number of prescriptions assessed in relation to pharmacological inappropriateness based on a list of 13 explicit prescription quality indicators.

RESULTS

Some 18.4% of the patients (66% females with mean age 79.8 years, 34% males with mean age 78.7 years) received one or more inappropriate prescriptions from their GP. An NSAID in a potentially harmful combination with another drug (7%) and a long-acting benzodiazepine (4.6%) were the most frequent inappropriate prescriptions made. Doctor characteristics associated with more inappropriate prescribing practice were old age and working single-handed with many elderly patients.

CONCLUSION

The study reveals areas where GPs' prescribing practice for elderly patients can be improved and which can be targeted in educational interventions.

Review article: The prevalence and clinical relevance of cytochrome P450 polymorphisms

BACKGROUND

Most drugs currently used in clinical practice are effective in only 25% to 60% of patients, while adverse drug reactions (ADRs) as a consequence of treatment are estimated to cost billions of US dollars and tens of thousands of deaths.

AIM

To review the prevalence and clinical significance of cytochrome P450 polymorphisms.

RESULTS

The cytochrome P450 enzyme families 1-3 are responsible for 70 to 80% of all phase I dependent drug metabolisms. In 90% metabolic activity dependents on six enzymes: CYP1A2, CYP3A, CYP2C9, CYP2C19, CYP2D6 and CYP2E1. Polymorphisms in the CYP450 gene can influence metabolic activity of the subsequent enzymes. A poor metabolizer (PM) has no or very poor enzyme activity. A consequence of PM is drug toxicity if no other metabolic route is available, or when multiple drugs are metabolized by the same cytochrome. In that case dose reduction is an option to prevent toxic effects.

CONCLUSIONS

In the future genotyping should be considered to identify patients who might be at risk of severe toxic responses, in order to guide appropriate individual dosage. Medical therapy should be a close cooperation between clinicians, pharmacologists and laboratory specialists, leading to reduced therapeutic errors, ADRs and health care costs.

Hospitalisations and emergency department visits due to drug-drug interactions: a literature review

PURPOSE

Our objective was to evaluate the incidence of adverse patient outcomes due to drug-drug interactions (D-DIs), the type of drugs involved and the underlying reason. As a proxy for adverse patient outcomes, emergency department (ED) visits, hospital admissions and re-hospitalisations were assessed.

METHODS

A literature search in the Medline and Embase database (1990-2006) was performed and references were tracked. An overall cumulative incidence was estimated by dividing the sum of the cases by the sum of the study populations.

RESULTS

Twenty-three studies were found assessing the relationship between D-DIs and ED-visits, hospitalisations or re-hospitalisations. The studies with a large study size showed low incidences and vice versa. D-DIs were held responsible for 0.054% of the ED-visits, 0.57% of the hospital admissions and 0.12% of the re-hospitalisations. In the elderly population, D-DIs were held responsible for 4.8% of the admissions. Drugs most often involved were NSAIDs and cardiovascular drugs. The reasons for admissions or ED-visits, which were most often found were GI-tract bleeding, hyper- or hypotension and cardiac rhythm disturbances.

CONCLUSION

This review provides information on the overall incidence of D-DIs as a cause of adverse patient outcomes, although there is still uncertainty about the impact of D-DIs on adverse patient outcomes. Our results suggest that a limited number of drugs are involved in the majority of cases and that the number of reasons for admission as a consequence of D-DIs seems to be modest.

Systematic review of the incidence and characteristics of preventable adverse drug events in ambulatory care

OBJECTIVE

To estimate the incidence and describe characteristics of preventable adverse drug events (pADEs) in ambulatory care.

DATA SOURCES

Studies were searched in PubMed (1966-March 2007), International Pharmaceutical Abstracts (1970-December 2006), the Cochrane database of systematic reviews (1993-March 2007), EMBASE (1980-February 2007), and Web of Science (1945-March 2007). Key words included medication error, adverse drug reaction, iatrogenic disease, outpatient, ambulatory care, primary health care, general practice, patient admission, hospitalization, observational study, retrospective studies, health services research, and follow-up studies. Additional articles were found in the reference sections of retrieved articles.

STUDY SELECTION AND DATA EXTRACTION

Peer-reviewed articles assessing pADEs in ambulatory care, with detailed descriptions/frequency distributions of (1) ADE/pADE incidence, (2) clinical outcomes, (3) associated drug groups, and/or (4) underlying medication errors were included. Study country, year and design, sample size, follow-up time, ADE/pADE identification method, proportion of ADEs/pADEs and ADEs/pADEs requiring hospital admission, and frequency distribution of adverse outcome, associated drug groups, or medication errors were extracted.

DATA SYNTHESIS

Twenty-nine studies met inclusion criteria: 14 were ambulatory-based and 15 were hospital-based. Seven studies enrolled only elderly patients. The median ADE incidence was 14.9 (range 4.0-91.3) per 1000 person-months, and the pADE incidence was 5.6 per 1000 person-months (1.1-10.1). The median ADE preventability rate was 21% (11-38%). The median incidence of ADEs requiring hospital admission was 0.45 (0.10-13.1) per 1000 person-months, and the median incidence of pADEs requiring hospital admission was 4.5 per 1000 person-months. Cardiovascular drugs, analgesics, and hypoglycemic agents together accounted for 86.5% of pADEs, and 77.2% of pADEs resulted in symptoms of the central nervous system, electrolyte/renal system, and gastrointestinal tract. Medication errors resulting in pADEs occurred in the prescribing and monitoring stages. The most frequent drug therapy problem and error of commission reported in ambulatory-based studies on pADEs was the use of inappropriate drugs (42.7%; 40.4-45%). For pADEs requiring hospital admission, the most frequent drug therapy problem and error of omission reported was inadequate monitoring (45.4%; range 22.2-69.8%). Failure to prescribe prophylaxis to patients taking nonsteroidal antiinflammatory drugs or antiplatelet drugs frequently caused gastrointestinal toxicity, whereas lack of monitoring of diuretic, hypoglycemic, and anticoagulant use caused over- or under-diuresis, hyper- or hypoglycemia, and bleeding.

CONCLUSIONS

ADEs in ambulatory care are common, with many being preventable and many resulting in hospitalization. Quality improvement programs should target errors in prescribing and monitoring, especially for patients using cardiovascular, analgesic, and hypoglycemic agents.

Adverse drug reaction monitoring in a secondary care hospital in South India

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

The benefits of adverse drug reaction (ADR) monitoring are well-known. Poor awareness and nonavailability of a central co-ordinating body resulted in lack of ADR monitoring in India. The National Pharmacovigilance Programme was recently initiated, encouraging ADR monitoring in selected centres, including our centre.

WHAT THIS STUDY ADDS

This is the first study of its kind at GHQH, Ootacamund that has provided insight into the burden of ADRs here. The incidence and severity of ADRs documented in our study is lower than those reported in comparable populations in Western studies but more than those reported in India.

AIMS

To ascertain the current burden of ADRs at a Government hospital in Ooty and to assess the severity of reported ADRs and the additional financial burden associated with ADRs.

METHODS

A prospective, spontaneous reporting study was conducted over a period of 9 months of inpatient admissions to the medical wards, co-ordinated by clinical pharmacists. The WHO definition of an ADR was adopted. The Naranjo algorithm scale was used for causality assessment. Confirmed ADRs were classified according to the Wills & Brown method and assessed for severity and patient outcomes. The average cost incurred in treating the ADRs was calculated.

RESULTS

Of the total of 187 adverse drug events (ADEs) reported, 164 reports from 121 patients were confirmed as ADRs, giving an overall incidence of 9.8%. This included 58 (3.4%) ADR related admissions and 63 (3.7%) ADRs occurring during the hospital stay. About two thirds of the reactions (102, 62.2%) were classified as probable. The majority of the reactions (88, 53.7%) were mild. Most patients (119, 72.6%) recovered from the incidence. The majority of the reactions were of type H (100, 61%) which indicates that they were not predictable and not potentially preventable. An average cost of 481 rupees ( pound 6) was spent on each patient to manage ADRs.

CONCLUSIONS

The incidence and severity of ADRs documented in our study are lower than those reported in comparable populations in Western studies but more than those reported in India.

Adverse drug events in cognitively impaired elderly patients

BACKGROUND/AIMS

Adverse drug events (ADEs) are a frequent problem encountered in the elderly. The aim of this study was to elucidate the factors that influence ADEs in an elderly population with cognitive impairment.

METHODS

242 patients were recruited from dementia clinics and assessed after 6 months for ADEs. The use of natural health products (NHPs) was also documented.

RESULTS

Backward logistic regression found that higher age (OR = 1.06; 95% CI 1.01-1.12), and greater cognitive impairment (OR = 0.94; 95% CI 0.90-0.98) were associated with an increased risk of developing an ADE while the use of NHPs (OR = 0.32; 95% CI 0.13-0.79) was associated with a decreased risk (chi(2) = 27.6, p < 0.001).

CONCLUSION

Risk of ADEs increased with greater age and cognitive impairment but decreased with the use of NHPs.

Repeat adverse drug reactions causing hospitalization in older Australians: a population-based longitudinal study 1980-2003

AIM

To examine trends in the rate of repeat adverse drug reactions (ADRs) causing hospitalization in older Australians and to identify the most common ADRs and drugs most often implicated in repeat and first-time ADRs.

METHODS

Analysis of routinely collected hospital record administrative data, with International Classification of Diseases external cause codes for ADRs extracted from the Western Australia (WA) Hospital Morbidity Data System and WA Death Register, for people aged > or =60 years in 1980-2003.

RESULTS

A total of 37 296 people aged > or =60 years with an ADR-related hospitalization were identified. Among them, 6853 (18.4%) patients had 10 212 repeat ADRs. Repeat ADRs consistently increased from 1980 and reached 30.3% of all ADRs by 2003. The mean time interval declined with each successive repeat ADR (810, 606 and 299 days for the first, second and higher ranked repeat episodes, respectively). The most common repeat ADRs were nausea/vomiting (8.0%), haemorrhage due to anticoagulants (5.5%), drug-induced osteoporosis (4.8%) and poisoning by cardiovascular agents (3.9%). The drugs most often involved in repeat ADRs were cardiovascular agents (15.6%), antineoplastic drugs (11.0%), corticoids (10.1%), anticoagulants (8.6%), antirheumatics/nonsteroidal anti-inflammatory drugs (5.1%) and opioids (4.9%). The trends of anticoagulants and antineoplastic drugs implicated in repeat ADRs were still rising at the end of the study. The specific drug classes involved in repeat ADRs differed in relative importance from first-time ADRs.

CONCLUSIONS

Repeat ADR-related hospitalizations have consistently increased in elderly Australians from 1980 to 2003. Strategies to ensure the safer use of medicines, in particular anticoagulants, in this population are warranted.

Inappropriate medication use in elderly lebanese outpatients: prevalence and risk factors

BACKGROUND

Inappropriate use of medications has become an international cause for concern in geriatric patients, who are at high risk of drug-related morbidity. This study is the first attempt to determine the prevalence of inappropriate drug use in elderly Lebanese outpatients, using community pharmacy data, and to identify factors that predict potentially inappropriate drug intake in this population.

METHODS

Records of elderly patients aged > or =65 years were selected from different community pharmacies. Each patient profile was reviewed and to confirm patient record information, in-person interviews were conducted with elderly patients between November 2004 and May 2005 by qualified pharmacists. Based on a literature review describing guidelines for the inappropriate use of medications in the elderly, courses of therapy were assessed and classified as either appropriate or inappropriate. Courses of therapy that were judged inappropriate were further classified according to the specific area of inappropriate use (i.e. Beers' criteria, duplicate therapy, indication, dose, dose frequency including missing doses, duration and discontinuation of therapy, adverse effects, drug-drug and/or drug-disease interactions, and poor memory). Statistical analyses were performed to estimate the prevalence of inappropriate medication use and to identify potentially predictive factors of such use arising from patients' sociodemographic characteristics, health factors and drug regimen intake.

RESULTS

A total of 350 elderly patient profiles were reviewed, from which 277 evaluable records were obtained. More than half (59.6%) of the patients taking drugs at the time of the study were taking at least one inappropriate medication. Inappropriate medication use was most frequently identified in terms of Beers' criteria (22.4%), missing doses (18.8%) or incorrect frequency of administration of drugs (13.0%). Factors predicting potentially inappropriate drug intake included female sex (65.7% vs 53.3% for males, p = 0.03) and alcohol intake (p = 0.007). There were also significant associations between the likelihood of use of an inappropriate drug and (i) increased number of medical illnesses (p < 0.00002); and (ii) consumption of an over-the-counter drug (OTC) and/or prescription drug (p = 0.048 and p = 0.0035, respectively). The likelihood of use of an inappropriate drug was higher again when patients concurrently used both OTC and prescription drugs (p < 0.0002).

CONCLUSION

The present study is the first to describe and assess inappropriate medication use by elderly outpatients in the Lebanese community setting. With increasing availability of newer and more appropriate medications, use of potentially inappropriate drugs may decrease. Pharmacists have a major role to play in counselling patients about the importance of appropriate drug use.

[Adverse drug reactions: an update review of the problem in Spain]

Adverse drug reactions (ADR) are an important clinical problem and their impact on the Spanish population is unknown. The aim of this study was to provide an overview of ADR based on a review of observational studies published in Spain since 1974. Twenty-seven studies of Spanish patients were selected from a total of 90 articles published in national and international journals between 1974 and 2004. Studies eligible for inclusion were identified with an especially designed checklist. The incidence of ADR among 139,799 patients was 3%; 0.6% of the events led to death, and 17% led to severe illness. Two-thirds (67%) of the ADR were classified as type A. The rate of hospitalization for ADR was 6.5%, and mean length stay was 4 +/- 1.3 days. Thirteen percent of the ADR were considered confirmed, and 57% were considered probable. Half (50%) of the ADR were considered preventable. The groups of medications involved most frequently were antibacterial, NSAID, psychoactive medications, bronchodilators, digoxin, non-opiate analgesics, vasodilators, antidiabetics and loop diuretics. The organs and systems involved most frequently were the digestive tract, skin, central nervous system, cardiovascular, endocrine and respiratory systems. The factors associated most strongly with ADR were advanced age and use of multiple medications. The relationships of gender, previous history of ADR and comorbidity with the incidence of ADR have yet to be established. This review of ADR provides useful information on the incidence of ADR in the Spanish population and serves as a baseline for future studies.

Influence of pharmacists' attitudes on adverse drug reaction reporting : a case-control study in Portugal

INTRODUCTION

Pharmacists can play a fundamental role in adverse drug reaction (ADR) reporting, although the factors that affect underreporting among these professionals are unknown. The objectives of this study were to identify (i) professional or demographic characteristics; and (ii) attitudes associated with pharmacists' ADR reporting in northern Portugal.

METHODS

We conducted a case-control study on a population of pharmacists employed in hospital and community pharmacies across Portugal's Northern Regional Health Authority catchment area in 2003. Cases (n=34) comprised pharmacists who had reported at least one ADR to the northern region's drug surveillance unit, and controls (n=280) were randomly sampled from pharmacists who had never reported an ADR. All were interviewed using a mail questionnaire. Most attitudes were based on Inman's 'seven deadly sins' and were measured using a continuous visual analogue scale. Answers were recorded in a range from 0 (total disagreement) to 10 (total agreement). Logistic regression was used to determine the ADR reporting adjusted odds ratio (OR) for a change in exposure corresponding to the interquartile range for each attitude.

RESULTS

The response rate was 86.8%. Reporting probability proved higher among hospital versus community pharmacists (adjusted OR 20.0; 95 CI 3.3, 125.0; p<0.001). Attitudes to ADRs were strongly associated with reporting probability. Hence, an interquartile decrease in any of the following attitudes increased the probability of reporting by (i) 223% (95% CI 51, 595; p < 0.05) for "Really serious ADRs are well documented by the time a drug is marketed"; (ii) 240% (95% CI 89, 508; p=0.002) for "I would only report an ADR if I were sure that it was related to the use of a particular drug"; (iii) 316% (95% CI 44, 1104; p=0.010) for "It is only necessary to report serious or unexpected ADRs"; and (iv) 171% (95% CI 13, 549; p=0.020) for "I do not have time to think about the involvement of the drug or other causes in ADRs".

CONCLUSIONS

ADR under-reporting is strongly associated with certain attitudes, possibly indicating that under-reporting could be minimised through educational interventions targeted at changing such attitudes. Pharmacists' ADR education must be improved and educational programmes should be focused on altering attitudes identified by the study as being associated with under-reporting. Our data also indicate that community pharmacists must be a priority target for this intervention.

Drug dosage adjustments according to renal function at hospital discharge

BACKGROUND

Adequate dosing of medication in renal impairment to prevent hospitalizations and adverse reactions is a growing concern in the aging society. There are several dosing guidelines available, but structural use is uncommon.

OBJECTIVE

To perform a retrospective analysis of the incidence of required versus implemented dosage adjustments according to guidelines in patients with renal insufficiency at discharge and evaluate specific determinants responsible for the percentage of overlooked dosage adjustments.

METHODS

Medication and laboratory data were collected from patients at discharge during February and November 2004. For patients with a calculated creatinine clearance less than 51 mL/min/1.73 m(2), the necessity for dosage adjustments was evaluated by pharmacists. All data were collected for further research and subsequent statistical analysis.

RESULTS

At discharge, 237 of 647 (36.6%) patients had a calculated creatinine clearance less than 51 mL/min/1.73 m(2). Dosage adjustment based on renal function was necessary in 411 of 1718 (23.9%) of prescriptions. These adjustments were performed in 242 (58.9%) prescriptions and not performed in 169 (41.1%) cases. The risk of not adjusting the dosage was significantly associated with serum creatinine levels greater than 1.71 mg/dL and creatinine clearance less than 35 mL/min/1.73 m(2) (p < 0.05). The risk of not adjusting the dosage was also significantly associated with drugs producing severe consequences when dosing guidelines were overlooked (p < 0.05).

CONCLUSIONS

In patients with a calculated creatinine clearance less than 51 mL/min/1.73 m(2), dosing according to their renal function can be improved. Because of the need and the association found in this study, an alert system could help prescribers and pharmacists to adapt drug dosage in patients with renal impairment.

Which drugs cause preventable admissions to hospital? A systematic review

AIMS

Previous systematic reviews have found that drug-related morbidity accounts for 4.3% of preventable hospital admissions. None, however, has identified the drugs most commonly responsible for preventable hospital admissions. The aims of this study were to estimate the percentage of preventable drug-related hospital admissions, the most common drug causes of preventable hospital admissions and the most common underlying causes of preventable drug-related admissions.

METHODS

Bibliographic databases and reference lists from eligible articles and study authors were the sources for data. Seventeen prospective observational studies reporting the proportion of preventable drug-related hospital admissions, causative drugs and/or the underlying causes of hospital admissions were selected. Included studies used multiple reviewers and/or explicit criteria to assess causality and preventability of hospital admissions. Two investigators abstracted data from all included studies using a purpose-made data extraction form.

RESULTS

From 13 papers the median percentage of preventable drug-related admissions to hospital was 3.7% (range 1.4-15.4). From nine papers the majority (51%) of preventable drug-related admissions involved either antiplatelets (16%), diuretics (16%), nonsteroidal anti-inflammatory drugs (11%) or anticoagulants (8%). From five studies the median proportion of preventable drug-related admissions associated with prescribing problems was 30.6% (range 11.1-41.8), with adherence problems 33.3% (range 20.9-41.7) and with monitoring problems 22.2% (range 0-31.3).

CONCLUSIONS

Four groups of drugs account for more than 50% of the drug groups associated with preventable drug-related hospital admissions. Concentrating interventions on these drug groups could reduce appreciably the number of preventable drug-related admissions to hospital from primary care.