Methods and systems to detect adverse drug reactions in hospitals

Incidence and patterns of adverse drug reactions among adult patients hospitalized in the University of Gondar comprehensive specialized hospital: A prospective observational follow-up study

BACKGROUND

Adverse drug reactions (ADRs) have continued to be a public health challenge with significant clinical and healthcare costs. However, little is known regarding the incidence of ADR in Ethiopia, particularly in the study setting. Thus, this study aimed to assess the incidence and patterns of ADRs in patients admitted to the University of Gondar comprehensive specialized hospital (UoGCSH).

METHODS

A prospective observational follow-up study was conducted on admitted patients at the medical ward in the UoGCSH from May to August 2022. A multifaceted approach involving daily chart review and patient interviews was employed to collect the data. A standard Naranjo ADR Probability Scale measuring tool was used to characterize the probability of existing ADR. The data was analyzed using the Statistical Package for Social Sciences (SPSS) version 25. Logistic regression analysis was employed to determine the association between the occurrence of ADRs and other variables. A p-value at the 95% confidence interval was considered statistically significant.

RESULTS

This study included 237 participants in total. The average length of follow-up was 16.4 (±5.2) days. Overall, 65 ADRs were identified, resulting an incidence rate of 27.4 (95% CI: 19.8-30.4) per 100 admissions. The most common ADRs were hypokalemia (10.7%), followed by constipation, diarrhea, hypotension, and rash (9.2% each). The majority of these ADRs (73.8%) were classified as "definite" by the Naranjo ADR probability scale. Gastrointestinal tract (GIT) (41.5%) and metabolic (18.6%) were the most frequently exposed systems for ADR. Antibiotics (26.2%) and cardiovascular medications (24.7%) were the most frequently implicated medications in existing ADRs. ADRs were significantly associated with age (p = 0.035), the presence of comorbidities (p = 0.021) and complications (p = 0.008), and receiving a higher number of medications (p = 0.04).

CONCLUSION

In this study, ADR was identified in about one-fourth of the participants. Older patients, patients with comorbidities and complications, and patients who received a higher number of medications were more likely exposed for ADRs. Healthcare providers should strictly follow the admitted patients to minimize ADRs.

Exploring Healthcare Professionals' Practices and Attitudes towards Monitoring and Reporting of Severe Adverse Drug Reactions

Healthcare professionals (HCPs) play a key role in the monitoring of severe adverse drug reactions (ADRs). The present study aims to explore practices and barriers of HCPs in severe ADR monitoring and reporting, to evaluate their attitudes towards the monitoring and to assess the related factors. Self-administered questionnaires produced in hard copy and Google form were sent to 510 HCPs by stratified random sampling. Of the 350 HCPs that responded (68.6%), 44.9% had ever monitored ADRs. The most common practices were the observation of abnormal symptoms for ADR identification (88.5%), discontinuation of the suspected drug for ADR management (88.5%) and advice on recurrent drug allergy for ADR prevention (88.5%). Most HCPs (93.0%) obtained further patient history to identify severe ADRs. The uncertainty of the causal relationship was a major barrier to ADR reporting (60.0%). Pharmacists were more involved with practices in ADR monitoring and reporting (OR 20.405; p < 0.001), whereas longer work experience (>20 years) was negatively related to the practices (OR 0.271; p = 0.024). Over one-third (37.6%) of HCPs had a positive attitude towards severe ADR monitoring. In conclusion, the practices in severe ADR monitoring varied among different professions. However, the barriers to the reporting of ADRs still exist; hence, improving knowledge and cooperation among HCPs should be promoted.

Actual drug-related harms in residential aged care facilities: a narrative review

INTRODUCTION

Older people in residential aged care facilities (RACFs) have a high risk of safety issues and concerns about the potential quality of care received. This narrative review investigates the types of actual drug-related harms, their prevalence, reporting of any standard definitions for these harms, and their identification methods.

AREAS COVERED

The authors conducted a systematic search on Ovid Embase, Ovid Medline, and PubMed from March 2001 to March 2021. This narrative review included all types of studies targeting aged care residents aged 65 years and above with actual drug-related harms.

EXPERT OPINION

The prevalence of actual drug-related harms in residents ranged from 0.07% to 63.0%. Falls, drug-drug interactions, neuropsychiatric symptoms, anaphylaxis, urinary tract infection, hypoglycemia, hypokalaemia, and acute kidney injury are the most common drug-related harms in older residents. Psychotropic drugs are the most common drug class implicated in these harms. Evidence related to the association between individual psychotropic drugs and injury, or harm is also lacking. Due to the variation in study duration, reported prevalence, identification methods, and absence of a definition for actual drug-related harms in most studies, further research is mandated to understand the prevalence and clinical implications of drug-related harms in older residents.

Incidence of adverse drug events in patients hospitalized in the medical wards of a teaching referral hospital in Ethiopia: a prospective observational study

BACKGROUND

Adverse drug events (ADEs) are an important public health problem with considerable clinical and economic costs. However there are limited studies of ADE incidence in adult inpatients in low-income countries, particularly in Ethiopia. Hence, this study aimed to assess the incidence of adverse drug events and associated factors in patients hospitalized in the medical wards of Wolaita Sodo University teaching referral hospital (WSUTRH).

METHODS

A prospective observational study was conducted involving 240 patients admitted to the medical wards of WSUTRH. A checklist was used for data collection, while standard tools were employed for assessing the probability and characterization of ADEs. A multifaceted approach involving daily chart review, patient interview, attendance at ward rounds and/or meetings, and staff reports were employed to collect the data. To identify factors independently associated with ADEs, logistic regression analysis was conducted using Stata version 15.

RESULTS

Patients were followed from ward admission to discharge, accounting for 2200 patient-days of hospital stay. Overall, 976 medications were ordered during the hospital stay. Sixty-four ADEs were identified with an incidence of approximately 27 per 100 admissions and 29 per 1000 patient days. Of the total ADEs, 59% were preventable. Regarding the severity, 2% of the ADEs were severe, while 54% were moderate. The risk of ADEs increased with longer hospital stay (LOHS) (p = 0.021), in patients with blood and immune disease diagnosis (p = 0.001), use of cardiovascular medicines (p = 0.028), and an increase in the number of medications prescribed (p = 0.021).

CONCLUSIONS

In this study, ADEs were identified in about one-quarter of the participants. Longer hospital stays, blood and immune diseases, cardiovascular medicines use, and multiple medication use had increased the likelihood of ADE occurrences. The majority of the ADEs were preventable, indicating the existence of a window of opportunity to ensure patient safety.

Serious adverse drug reactions in sub-Saharan Africa in the era of antiretroviral treatment: A systematic review

We aimed to summarize and describe the burden of serious adverse drug reactions (ADRs) in sub-Saharan Africa (SSA) in the era of antiretroviral therapy. We searched Medline, CINAHL, Africa-Wide Information, Scopus, and Web of Science, without language restriction up to March 2021. We hand-searched reference lists, conference abstracts, and dissertation databases. We included studies reporting proportions of admissions attributed to ADRs, admissions prolonged by ADRs, or in-hospital deaths attributed to ADRs. Two reviewers independently screened the studies, reviewed the study quality using a previously published tool, and extracted the data. We tested for heterogeneity using I2 -statistics and summarized the study results using medians and interquartile ranges. Subgroup analyses summarized the results by study quality, setting, methodology, and population. From 1005 unique references identified, we included 15 studies. Median study quality was 7/10; heterogeneity was very high. Median [IQR] proportion of admissions attributed to ADRs was 4.8% [1.5% to 7.0%] (14 studies) and 6.4% [4.0% to 8.4%] in nine active surveillance studies in adults. Two pediatric studies reported the proportion of admissions prolonged by ADRs (0.29% and 0.99%). Three studies reported the proportion of in-hospital deaths attributed to ADRs (2.5%, 13%, and 16%). Antiretroviral and antituberculosis drugs were often implicated in serious ADRs. Evidence of the burden of serious ADRs in SSA is patchy and heterogeneous. A few high-quality studies suggest that the burden is considerable, and that it reflects the regional impact of the HIV pandemic. Further characterization of this burden is required, ideally in studies of standardized methodology.

Medication-related adverse events in health care-what have we learned? A narrative overview of the current knowledge

Purpose

Although medication-related adverse events (MRAEs) in health care are vastly studied, high heterogeneity in study results complicates the interpretations of the current situation. The main objective of this study was to form an up-to-date overview of the current knowledge of the prevalence, risk factors, and surveillance of MRAEs in health care.

Methods

Electronic databases (PubMed, MEDLINE, Web of Science, and Scopus) were searched with applicable search terms to collect information on medication-related adverse events. In order to obtain an up-to-date view of MRAEs, only studies published after 2000 were accepted.

Results

The prevalence rates of different MRAEs vary greatly between individual studies and meta-analyses. Study setting, patient population, and detection methods play an important role in determining detection rates, which should be regarded while interpreting the results. Medication-related adverse events are more common in elderly patients and patients with lowered liver or kidney function, polypharmacy, and a large number of additional comorbidities. However, the risk of MRAEs is also significantly increased by the use of high-risk medicines but also in certain care situations. Preventing MRAEs is important as it will decrease patient mortality and morbidity but also reduce costs and functional challenges related to them.

Conclusions

Medication-related adverse events are highly common and have both immediate and long-term effects to patients and healthcare systems worldwide. Conclusive solutions for prevention of all medication-related harm are impossible to create. In the future, however, the development of efficient real-time detection methods can provide significant improvements for event prevention and forecasting.

Potential Direct Costs of Adverse Drug Events and Possible Cost Savings Achievable by their Prevention in Tuscany, Italy: A Model-Based Analysis

INTRODUCTION

Adverse drug events (ADEs) may represent an important item of expenditure for healthcare systems and their prevention could be associated with a relevant cost saving.

OBJECTIVE

The objective of this study was to simulate the annual economic burden for ADEs in Tuscany (Italy) and the potential cost savings related to avoidable ADEs.

METHODS

A systematic review was performed, according to the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) statements, on observational studies published from 2006 to 2016 in MEDLINE and EMBASE, focusing on direct costs of ADEs in the inpatient setting from high-income countries. The mean probability of preventable ADEs was estimated over the included studies. The mean ADE cost was calculated by means of Monte Carlo simulation. We then extrapolated the spontaneous reports of ADEs in Tuscany, Italy in 2016 from the Italian National Pharmacovigilance Network (Rete Nazionale di Farmacovigilanza), and we assumed the same costs and preventability probability for these as obtained in the systematic review. Finally, we simulated the possible costs of ADEs and preventable ADEs in Tuscany. Three sensitivity analyses were also performed to test the robustness of the results.

RESULTS

Of 11,936 articles initially selected, 12 observational studies were included. The estimated mean [± standard deviation (SD)] ADE cost was €2471.46 (± €1214.13). The mean (± SD) probability of preventable ADEs was 45% (± 21). The Tuscan expenditure for ADEs was €3,406,280.63 per million inhabitants (95% confidence interval (CI) 1,732,910.44-5,079,664.61) and the potential cost saving was €1,532,760.25 per million inhabitants (95% CI 779,776.1-2,285,750.60). Sensitivity analyses confirmed the robustness of the results.

CONCLUSIONS

The present simulation showed that ADEs could have a relevant economic impact on the Tuscan healthcare system. In this setting, the prevention of ADEs would result in important cost savings. These results could be likely extended to other healthcare systems.

The economic burden of preventable adverse drug reactions: a systematic review of observational studies

INTRODUCTION

Adverse drug reactions (ADRs) are an important cause of morbidity and mortality worldwide. They are associated with healthcare costs due to hospital admissions or prolonged length of stay, as well as additional interventions. The aim of this study was to conduct a systematic review of observational studies to evaluate the economic impact of preventable ADRs.

AREAS COVERED

Published observational research investigating the cost of preventable ADRs in Western countries (limited to the USA and European countries).

EXPERT OPINION

Several reviews have been carried out in the field of the ADR epidemiology but fewer reviews have investigated the economic impact of ADRs, and at the time of writing, none has focused on preventable ADRs. The reason why future research should focus on the costs of preventable ADRs is that both the costs and the negative clinical outcomes are preventable, and as such, are a key point of public health policy action. Nevertheless, the present review highlights an important and sobering limitation of published research on the cost of preventable ADRs, of which the major limitation is the heterogeneity in methods and in reporting which limit what can be known through the summarizing work of a systematic review.

[Performance and optimisation of a trigger tool for the detection of adverse events in hospitalised adult patients]

OBJECTIVE

To characterise the performance of the triggers used in the detection of adverse events (AE) of hospitalised adult patients and to define a simplified panel of triggers to facilitate the detection of AE.

METHOD

Cross-sectional study of charts of patients from a service of internal medicine to detect EA through systematic review of the charts and identification of triggers (clinical event often related to AE), determining if there was AE as the context in which it appeared the trigger. Once the EA was detected, we proceeded to the characterization of the triggers that detected it. Logistic regression was applied to select the triggers with greater AE detection capability.

RESULTS

A total of 291 charts were reviewed, with a total of 562 triggers in 103 patients, of which 163 were involved in detecting an AE. The triggers that detected the most AE were "A.1. Pressure ulcer" (9.82%), "B.5. Laxative or enema" (8.59%), "A.8. Agitation" (8.59%), "A.9. Over-sedation" (7.98%), "A.7. Haemorrhage" (6.75%) and "B.4. Antipsychotic" (6.75%). A simplified model was obtained using logistic regression, and included the variable "Number of drugs" and the triggers "Over-sedation", "Urinary catheterisation", "Readmission in 30 days", "Laxative or enema" and "Abrupt medication stop". This model showed a probability of 81% to correctly classify charts with EA or without EA (p <0.001; 95% confidence interval: 0.763-0.871).

CONCLUSIONS

A high number of triggers were associated with AE. The summary model is capable of detecting a large amount of AE, with a minimum of elements.

A systematic review of observational studies evaluating costs of adverse drug reactions

Introduction

The growing evidence of the increased frequency and severity of adverse drug events (ADEs), besides the negative impact on patient’s health status, indicates that costs due to ADEs may be steadily rising. Observational studies are an important tool in pharmacovigilance. Despite these studies being more susceptible to bias than experimental designs, they are more competent in assessing ADEs and their associated costs.

Objective

To identify and characterize the best available evidence on ADE-associated costs.

Methods

MEDLINE, Cochrane Library, and Embase were searched from 1995 to 2015. Observational studies were included. The methodological quality of selected studies was assessed by Cochrane Collaboration tool for experimental and observational studies. Studies were classified according to the setting analyzed in “ambulatory”, “hospital”, or both. Costs were classified as “direct” and “indirect”. Data were analyzed using descriptive statistics. The total incremental cost per patient with ADE was estimated.

Results

Twenty-nine (94%) longitudinal observational studies and two (7%) cross-sectional studies were included. Twenty-three (74%) studies were assessed with the highest methodological quality score. The studies were mainly conducted in the US (61%). Twenty (65%) studies evaluated any therapeutic group. Twenty (65%) studies estimated costs of ADEs leading to or prolonging hospitalization. The “direct costs” were evaluated in all studies, whereas only two (7%) also estimated the “indirect costs”. The “direct costs” in ambulatory ranged from €702.21 to €40,273.08, and the in hospital from €943.40 to €7,192.36.

Discussion

Methodological heterogeneities were identified among the included studies, such as design, type of ADEs, suspected drugs, and type and structure of costs. Despite such discrepancies, the financial burden associated with ADE costs was found to be high. In the light of the present findings, validated methods to measure ADE-associated costs need future research efforts.

[Nursing role in reporting adverse drug reactions]

BACKGROUND

The spontaneous report system, in which suspected adverse drug reaction (ADR) are reported by healthcare workers, is currently one of the primary methods to prevent and discover new and serious ADR to marketed medicinal products. The collaboration of nursing professionals with this task makes it possible to improve patient safety and to reduce ADR costs. Although a total of 781 cases of ADR cases were reported in Navarra in 2011, only 7.33% were reported by nurses. The objectives werw to determine the factors that influence nurses in reporting of ADR, and second, to devise strategies which help to increase reporting.

MATERIAL AND METHODS

A bibliographic search for articles that included the words: reacciones adversas medicamentosas (adverse drug reactions), notificación (reporting) and enfermería (nursing) was conducted using the PubMed and Cinhal databases. A total of 107 articles were retrieved, of which 27 were selected according to inclusion and exclusion criteria.

RESULTS

The conclusion learned by reading and analyzing the selected articles was that the factors that affect the notification depend on the attitude of the notifier, as well as personal and professional factors. The main strategies to encourage notification are education and training, motivation, and the availability of facilitating tools.

CONCLUSIONS

The main factors that have an influence on under-notification are the lack of knowledge and motivation among professionals. To solve the problem of under-notification, the main actions and strategies to undertake are education, motivation and persistence.

[Do pediatricians identify adverse drug reactions even when they do not report them?]

INTRODUCTION

Spontaneous notification depends on the ability of pediatricians to identify adverse drug reactions (ADRs) along with their habit of reporting these incidents. During the years 2008 and 2009, the frequency of reports of ADRs to the Electronic Program of Pharmacovigilance (SISFAR) in the Hospital Infantil of Mexico Federico Gomez (HIMFG) was low (0.44% and 0.20%, respectively). Because of the above, the ability of pediatricians from the Emergency Department (ED) to identify ADRs using the clinical chart review was evaluated in 2010 in this study.

METHODS

A descriptive, observational, cross-sectional retrospective study was conducted in the ED from March 1 to August 31. ADRs were classified and quantified as "ADRs identified by pediatricians" when there was evidence in the clinical chart that pediatricians associated a clinical sign, symptom and laboratory value with an ADR. The numbers of notifications reported in SISFAR were quantified. Descriptive analysis was done using SPSS v.18.

RESULTS

Considering patients who were admitted to the ED, the frequency of ADRs was 21.8%. The frequency of ADRs identified by physicians in clinical charts was 86%. The pharmacist detected 14% of ADRs. The frequency of ADRs reported by physicians was 6.1%.

CONCLUSIONS

Although identification of ADRs in the clinical charts by pediatricians was high, it is possible that some ADRs were undetected. Because underreporting was very high, it is necessary to take actions to improve the reporting process.

Clinical evaluation of the ADE scorecards as a decision support tool for adverse drug event analysis and medication safety management

AIMS

The prevention of adverse drug events (ADEs) demands co-ordination of different health care professionals. ADE scorecards are a novel approach to raise the team awareness regarding ADE risks and causes. It makes information on numbers and on possible causes of possible ADE cases available to the clinical team. The aim of the study was to investigate the usage and acceptance of ADE scorecards by healthcare professionals and their impact on rates of possible ADEs.

METHODS

ADE scorecards were introduced in three departments of a French hospital. A controlled time series analysis of ADE data was conducted to assess the impact of the ADE scorecards. In addition, qualitative interviews and a standardized survey with all participating staff members were performed.

RESULTS

Physicians, nurses and pharmacists found ADE scorecards effective to increase medication safety and recommended future usage. The time-series analysis did not show changes in rates of possible ADEs.

CONCLUSION

ADE scorecards appear to be useful to raise awareness of ADE-related issues among professionals. Although the evaluation did not show significant reductions of ADE rates, the participating physicians, nurses and pharmacists believed that the ADE scorecards could contribute to increased patient safety and to a reduction in ADE rates. Strategies need to be designed to integrate ADE scorecards better into the clinical routine and to increase the precision of ADE detection.

Comparative epidemiology of hospital-acquired adverse drug reactions in adults and children and their impact on cost and hospital stay--a systematic review

PURPOSE

To study and analyze the comparative impact of hospital-acquired adverse drug reactions (ADRs) in adult and pediatric patients in terms of the economic implications, (length of) hospital stay, and salient features in relation to the incidence rate, severity, morbidity, mortality, and preventability of the ADRs.

METHODS

A systematic search to identify and retrieve relevant articles/studies in the PubMed, Medline, Scopus, MEDPAR, and Cochrane databases and by the Google search engine was performed for the study period 2000 to April 2013. In total, 51 studies were identified on patients hospitalized for ADRs, and these were included in the study. The incidence rate of ADRs, their severity, mortality, morbidity, preventability, cost, and association with extended hospital stay due to ADRs were extracted and scrutinized.

RESULTS

Hospital-acquired ADRs are more widely studied in adults than in children, and the incidence rate is higher in the former. However, a wide variation in the incidence rate worldwide is observed in both groups. Irrespective of the ages of patients, ADRs are among the most frequent causes of morbidity and mortality. Interestingly, preventable ADRs are more frequently observed in patients at the younger and older ends of the age spectrum. Hospital-acquired ADRs place an immense economic burden on healthcare systems, with the overall cost for a hospitalized patient with an ADR reported to be $2,401 per patient, which is equivalent to a 19.86 % additional increase in the total cost of care and an increase in average length of hospital stay of 8.25 %.

CONCLUSION

Based on the findings of this review, we suggest that excellent assertive measures of pharmacovigilance with the aim to diminish the incidence rate of hospital-acquired ADRs and support the development of interventions are needed to promote vital facets of drug safety with an overall objective to avert potential ADRs.

Costs of adverse drug events in German hospitals--a microcosting study

OBJECTIVE

In Germany, only limited data are available to quantify the attributable resource utilization associated with adverse drug events (ADEs). The aim of this study was twofold: first, to calculate the direct treatment costs associated with ADEs leading to hospitalization and, second, to derive the excess costs and extra hospital days attributable to ADEs of inpatient treatments in selected German hospitals.

METHODS

This was a retrospective and medical record-based study performed from the hospitals' perspective based on administrative accounting data from three hospitals (49,462 patients) in Germany. Total treatment costs ("analysis 1") and excess costs (i.e., incremental resource utilization) between patients suffering from an ADE and those without ADEs were calculated by means of a propensity score-based matching algorithm ("analysis 2").

RESULTS

Mean treatment costs ("analysis 1") of ADEs leading to hospitalization (n = 564) were €1,978 ± 2,036 (range €191-18,147; median €1,446; €843-2,480 [Q1-Q3]). In analysis 2, the mean costs of inpatients suffering from an ADE (n = 1,891) as a concomitant disease or complication (€5,113 ± 10,059; range €179-246,288; median €2,701; €1,636-5,111 [Q1-Q3]) were significantly higher (€970; P < 0.0001) than those of non-ADE inpatients (€4,143 ± 6,968; range €154-148,479; median €2,387; €1,432-4,701 [Q1-Q3]). Mean inpatient length of stay of ADE patients (12.7 ± 17.2 days) and non-ADE patients (9.8 ± 11.6 days) differed by 2.9 days (P < 0.0001). A nationwide extrapolation resulted in annual total treatment costs of €1.058 billion.

CONCLUSIONS

This is one of the first administrative data-based analyses calculating the economic consequences of ADEs in Germany. Further efforts are necessary to improve pharmacotherapy and relieve health care payers of preventable treatment costs.

Adverse Drug Reactions in Children--International Surveillance and Evaluation (ADVISE): a multicentre cohort study

BACKGROUND

A previous meta-analysis reported that 9.5% of hospitalized children suffered from an adverse drug reaction (ADR); however, reported incidences among studies varied.

OBJECTIVE

To enhance the knowledge of ADRs in paediatric hospitalized patients at a global level we investigated the incidence and characteristics of ADRs in hospitalized children in European and non-European countries.

METHODS

A prospective observational cohort study was conducted in academic and non-academic hospitals in five countries: Australia, Germany, Hong Kong, Malaysia and the UK. Children aged 0-18 years admitted during a 3-month period (between 1 October 2008 and 31 December 2009) were recruited. The main outcome measures were incidence, causality and outcome of ADRs.

RESULTS

A total of 1278 patients (1340 admissions) were included [Australia n = 146 (149 admissions), Germany n = 376 (407), Hong Kong n = 143 (149), Malaysia n = 300 (314) and the UK n = 313 (321)]. The median age was 2 years (interquartile range [IQR] 0-7). Patients received a total of 5367 drugs (median 3; IQR 2-5) and median length of hospital stay was 4 days (IQR 3-7). A total of 380 ADRs were identified in 211 patients. The resultant ADR incidence of 16.5% (95% CI 14.5, 18.7) varied significantly between countries (p < 0.001). The highest incidences were observed in Malaysia and the UK. 65.3% (n = 248) of ADRs were found to be probable, and 24% of the ADRs were serious, with one being fatal.

CONCLUSIONS

By comparing data from five countries in Europe, Asia and Australia we have shown that the incidence of ADRs in hospitalized children is at least as high as incidences published in adults. However, the variation between countries was mainly due to different populations and treatment strategies. Particular attention should be given to opioid use in hospitalized children.

A systematic review to evaluate the accuracy of electronic adverse drug event detection

OBJECTIVE

Adverse drug events (ADEs), defined as adverse patient outcomes caused by medications, are common and difficult to detect. Electronic detection of ADEs is a promising method to identify ADEs. We performed this systematic review to characterize established electronic detection systems and their accuracy.

METHODS

We identified studies evaluating electronic ADE detection from the MEDLINE and EMBASE databases. We included studies if they contained original data and involved detection of electronic triggers using information systems. We abstracted data regarding rule characteristics including type, accuracy, and rationale.

RESULTS

Forty-eight studies met our inclusion criteria. Twenty-four (50%) studies reported rule accuracy but only 9 (18.8%) utilized a proper gold standard (chart review in all patients). Rule accuracy was variable and often poor (range of sensitivity: 40%-94%; specificity: 1.4%-89.8%; positive predictive value: 0.9%-64%). 5 (10.4%) studies derived or used detection rules that were defined by clinical need or the underlying ADE prevalence. Detection rules in 8 (16.7%) studies detected specific types of ADEs.

CONCLUSION

Several factors led to inaccurate ADE detection algorithms, including immature underlying information systems, non-standard event definitions, and variable methods for detection rule validation. Few ADE detection algorithms considered clinical priorities. To enhance the utility of electronic detection systems, there is a need to systematically address these factors.

Adverse drug reactions in a complementary medicine hospital: a prospective, intensified surveillance study

Background. Anthroposophic medicine is one of the widely used approaches of complementary and alternative medicine. However, few prospective studies have generated safety data on its use. Objectives. We aimed to assess adverse drug reactions (ADRs) caused by anthroposophical medicines (AMEDs) in the anthroposophical Community Hospital Havelhoehe, GERMANY. Study Design and Methods. Between May and November 2007, patients of six medical wards were prospectively assessed for ADRs. Suspected ADRs occurring during hospitalization were documented and classified in terms of organ manifestation (WHO SOC-code), causality (according to the Uppsala Monitoring Centre WHO criteria), and severity. Only those ADRs with a severity of grade 2 and higher according to the CTCAE classification system are described here. Results. Of the 3,813 patients hospitalized, 174 patients (4.6%) experienced 211 ADRs (CTCAE grade 2/3 n = 191, 90.5%, CTCAE grade 4/5 n = 20, 9.5%) of which 57 ADRs (27.0%) were serious. The median age of patients with ADRs (62.1% females) was 72.0 (IQR: 61.0; 80.0). Six patients (0.2%) experienced six ADRs (2.8% of ADRs) caused by eight suspected AMEDs, all of which were mild reactions (grade 2). Conclusion. Our data show that ADRs caused by AMEDs occur rarely and are limited to mild symptoms.

Risk factors associated with adverse drug reactions in hospitalised children: international multicentre study

BACKGROUND

Understanding the epidemiology and risk factors of adverse drug reactions (ADRs) is important in order to develop appropriate prevention strategies. This study aimed to identify risk factors associated with ADRs in hospitalised children and recommend strategies to minimise ADRs.

METHODS

A prospective multicentre cohort study was conducted on paediatric general medical wards in five European and non-European hospitals. ADRs were identified by intensive chart review. Multivariable logistic regression was used to investigate risk factors associated with ADRs. For the risk factor analysis, prescribed drugs were divided into high-risk and low-risk drug groups. Analgesics, anti-epileptics, antibacterials and antimycotics for systemic use, corticosteroids for systemic use and immunosuppressant agents were considered as high-risk groups whereas the remaining drug classes were defined as low-risk drug groups.

RESULTS

A total of 1,253 paediatric patients were identified [Australia (n = 145), Germany (n = 372), Hong Kong (n = 138), Malaysia (n = 291), UK (n = 307)]. A total of 328 ADRs were observed in 16.7% of patients (186/1,115). Use of five or more low-risk drugs per patient or three or more high-risk drugs was a strong predictor for ADRs (OR 4.7, 95% CI 2.4-9.3; OR 6.5, 95% CI 2.7-16.0 respectively; p < 0.001). Older children were more likely to experience ADRs; gender was not significantly associated.

CONCLUSION

To reduce the risk of ADRs in children, clinicians and pharmacists should aim to minimise polypharmacy and be aware of higher ADR risks associated with some drug groups.

Effect of an intervention on the features of adverse drug reactions spontaneously reported in a hospital

OBJECTIVES

A continuous intervention based on healthcare management agreements was associated in our hospital with an increase in the absolute number of spontaneous reporting of adverse drug reactions (ADRs), and also with an increase in the number of reports of serious or unexpected ADRs and ADRs associated with new drugs. The objective was to analyse the effect of this intervention on the features of ADRs spontaneously reported in a hospital, the drugs involved and the number of signals identified.

METHODS

A longitudinal study with two periods, the 1st period without intervention from 1998 to 2002 and the 2nd period with intervention from 2003 to 2005, was carried out in a tertiary teaching hospital. Changes between the two periods with regard to the following variables were analysed: the patients' characteristics, such as gender and age; the reported ADRs, and the medical assistance required; the suspected drugs involved in the ADRs; the main signals identified.

RESULTS

Gender and age distribution of patients described in the spontaneous reports were no different in the two periods. During the second period, spontaneously reported cases requiring hospital admission and those occurring in hospital increased (236 from 2 in the first period and 277 from 99 in the first period respectively) and cases from outpatient hospital consultations began to be reported (13.9% of reports). The spontaneous reporting on all kinds of ADRs and drugs increased during the second period. Cutaneous reactions were the most frequently spontaneously reported ADRs in both periods followed by cardiovascular and neurological reactions in the first period, and haematological and gastrointestinal reactions in the second one. However, during the second period the higher increase was for endocrinological, urinary and hepatic reactions. Systemic antibiotics, anti-thrombotics and cardiac therapy drugs were the most common therapeutic subgroups reported to be suspected drugs in both periods, but in the second period the proportion of immunostimulants, beta blocking agents, immunosuppressants and psychoanaleptics increased. No signals were recognised during the first period; however, two signals and one additional safety concern were identified during the second.

CONCLUSION

An intervention based on healthcare management agreements, was associated with an important increase in spontaneous reporting of ADRs by hospital physicians and also with a change in terms of the type of ADRs identified affecting different organs or systems, and the therapeutic groups of drugs involved. Future studies should analyse the effect of different types of intervention on the spontaneous reporting of ADRs in hospitals.

Adverse drug reaction reporting in Australian hospitals

Objective

To determine the status of adverse drug reaction (ADR) reporting in Australian hospitals. Method Postal questionnaire to all 299 directors of pharmacy in Australian hospitals.

Key findings

The response rate was 49.5%. Hospitals of different size were well represented: &lt;100 beds (23%), 100–199 beds (35%) and 200–499 beds (30%). ADR policies were reported by 67% of pharmacy departments. In most hospitals, doctors or pharmacists were responsible for ADR submissions to the Australian ADR Advisory Committee (ADRAC). Follow-up action included reports to Drug and Therapeutics Committees (57%) and drug bulletins (37%). Advice on ADRs was forwarded to the patient, the general practitioner (GP) and the community pharmacist by 96%, 89% and 11% of hospitals. Methods of informing patients were verbal (91%), card (17%) or letter (13%). Methods used to notify GPs included discharge summary (70%), letter (26%) or via the patient (15%). Data from ADRAC indicated a median 2.5 (range 0–362) reports from participating hospitals in 2000. The median ADR reporting rate was 0.02% (range 0–1.09) of patient admissions. There was no association between ADR reporting rates and the existence of an ADR policy or a centralised ADR reporting system. There was an association between hospital ADR reporting rates and provision of feedback or a reward for ADR reporting (P&lt;0.001).

Conclusions

Procedures or policies for ADR reporting are available in most Australian hospitals but this has no direct effect on ADR reporting rates. These findings suggest a gap between policy and implementation of ADR reporting. Strategies to improve ADR reporting could include improved feedback and electronic submissions to ADRAC from a centralised service.

Adverse drug events in hospitals: a systematic review

The objective of this study was to evaluate studies on the occurrence of adverse drug events (ADEs) in hospitals in order to learn about their frequency and characteristics, comparing the methods for identifying them and the various definitions. A search was conducted on MEDLINE and identified studies published from 2000 to 2009. Inclusion criteria were: studies in populations not selected for specific diseases or drugs and ADEs that occurred during hospitalization. Twenty-nine studies were selected, displaying multiple sources of heterogeneity, including differences in the study populations, surveillance techniques, definitions of ADEs, and indicators. The proportion of patients with ADEs ranged from 1.6% to 41.4% of inpatients and the rates ranged from 1.7 to 51.8 events/100 admissions. A considerable share of these events could have been avoided. The findings show that ADEs in inpatients are a public health problem. However, further studies are needed to monitor these adverse events in order to effectively promote safe drug use.

Factors predicting hospital readmissions related to adverse drug reactions

OBJECTIVE

To analyse the contribution of adverse drug reactions (ADR) to hospital readmissions.

METHODS

This was a case-control study in which unscheduled admissions of patients who had been admitted to the hospital during the two previous months were assessed during a 21-month period. The patient was considered a case when the main diagnosis of readmission complied with the World Health Organisation's definition of an ADR. For each case, two controls were selected from those patients that had been admitted for ADR without readmission (n = 177). Information on drugs and other risk factors was obtained from cases by interview and from controls by clinical record review.

RESULTS

There were 26,559 unscheduled admissions of which 81 were readmissions associated with ADR (4.5% of the unscheduled readmissions). There were no statistically significant correlations with sex, age or medical history, with the exception of arterial hypertension. The main drug products causing readmission were acenocoumarol (15, 18.5%), antihypertensive-diuretics (14, 17.3%), anticancer drugs (11, 13.6%) and digoxin (seven, 8.6%). In the multivariate logistic analysis, the variables predicting readmission were acenocoumarol [odds ratio (OR) 12.2, 95% confidence interval (CI) 3.8-38.3, P < 0.0001], a record of diabetes mellitus (OR 2.6, 95% CI 1.3-5.5, P < 0.01), the number of drugs taken at the moment of ADR (OR 1.2, 95% CI 1.1-1.4, P < 0.001) and high blood pressure (OR 0.3, 95% CI 0.2-0.6, P < 0.001) even though the latter was a negative predictor, preventing readmission. Of the 81 readmissions associated with ADR, 28 (34.6%) were preventable.

CONCLUSION

A medical record of diabetes mellitus, polypharmacy and acenocoumarol treatment were risk factors predicting hospital readmission related to ADR.

Ten years of adverse drug reaction reports for the multiple sclerosis immunomodulatory therapies: a Canadian perspective

Adverse drug reaction (ADR) reporting is essential in the post-marketing surveillance of drugs, detection of serious adverse reactions, and has been the basis for drug withdrawals. The study aimed to examine ADR reporting patterns to the multiple sclerosis (MS) immunomodulatory drugs (IMD) in Canada. All ADRs reported to the Canadian ADR Monitoring Program (CADRMP) from 1965 to March 2006 ( n = 193 208) were accessed and ADRs in which an IMD for MS (beta-interferon or glatiramer acetate) was the suspected drug extracted ( n = 888 reports were dated March/96—March/06). Almost half of all IMD ADRs reports (438/888) were sourced through the patient compared to 14.9% (10 649/71 373) of all ADRs reported to CADRMP over the same period. Of IMD ADR reports, 88.7% (788/888) were directed through the manufacturer compared to 57.7% (41197/71373) of all ADRs. Encouragement to others involved in patient care, such as pharmacists, nurses and physicians might enhance reporting of MS ADRs. Despite the limitations of ADR reporting data, previously unpublished case reports in several understudied MS populations were detailed: paediatrics (≤16 years old, n = 4), the elderly (≥65 years, n = 23) and during pregnancy ( n = 12). In addition, 46 deaths suspected by the reporter as being related to IMD treatment were detailed as well as three possible drug interactions. Multiple Sclerosis 2008; 14: 94—105. http://msj.sagepub.com

Detection and incidence of drug-induced agranulocytosis in hospital: a prospective analysis from laboratory signals

AIMS

Our objectives were to assess the detection and incidence of drug-induced agranulocytosis in two university hospitals using hematology laboratory data.

METHODS

A prospective study was undertaken at Toulouse University Hospital (France) and Navarra University Hospital (Spain) for 1 year (from 1 May 2004 to 30 April 2005). Using a computerized process and hematology laboratory data, all neutrophil counts with a value less than 500/mm(3) were registered, allowing identification of inpatients suffering from agranulocytosis during the period of the study. Medical records of all selected patients were then consulted. Cytostatic drugs were excluded from this study.

RESULTS

During the period of the study, 225,659 neutrophil counts were performed in both hospitals, of which 2,835 (1.26%) had a neutrophil count less than 500/mm(3), corresponding to 739 patients. Seventeen patients were excluded because of lack of data, and 20 cases of infants younger than 3 months were excluded. Among the remaining patients (n = 702), 23 cases of drug-induced agranulocytosis (excluding cytostatic drugs) were suspected. All cases were classified as "serious" since they led to death in 2 cases, hospitalization or prolongation of hospitalization in 19 cases and threatening of vital prognosis in 2 cases. Withdrawal of suspected drugs was done in all cases with regression of neutropenia in 21 cases. According to hospitalization data, the annual incidence of drug-induced agranulocytosis was 1.62 (1.0-2.6) per 10,000 inpatients in Toulouse University hospital (based on 534 cases) and 3.24 (0.9-8.3) per 10,000 inpatients in Navarra University Hospital (based on 168 cases). The involved drugs were mainly antibacterial (30.4%), immunosuppressive (17.4%), antithyroid (13.0%), antiplatelet (8.7%) and nonsteroidal anti-inflammatory (8.7%) ones. Only seven cases from Toulouse University Hospital were spontaneously reported by physicians during the same period. Thus, the underreporting coefficient (U) was 2.71 (63.2%) in France.

CONCLUSION

Our survey allowed us to identify the suspected drug-induced agranulocytosis through a prospective study in a large sample of inpatients using only laboratory data analysis. We also note an important underreporting rate of this serious adverse drug reaction (ADR) to the official French pharmacovigilance system. Laboratory data analysis could be used for identifying serious ADRs.

Adverse-drug-event rates for high-cost and high-use drugs in the intensive care unit

PURPOSE

The rates of adverse drug events (ADEs) associated with high-cost and high-use drugs in the intensive care unit (ICU) were studied.

METHODS

This retrospective analysis was conducted from October 1997 through June 2001 in a 647-bed academic medical center with over 120 ICU beds. Adult patients with a documented ADE occurring in the ICU were included in the analysis. ADE information, including suspected medication, causality, preventability, and severity, was extracted from the institutional ADE database. Published definitions of ADEs and published scales for causality and severity assessments were used. High-cost medications were those in the top 50% of cumulative ICU medication costs, and high-use medications accounted for the upper 50% of all medications used in the ICU. Between-group comparisons of ADE rates, preventability, and severity associated with high-cost and high-use medications were conducted.

RESULTS

Of the 17 medications that were considered high cost, 9 (53%) were associated with ADEs. Of the 15 medications that met the criteria for high-use drugs, 12 (80%) were associated with ADEs. The rates of ADEs associated with high-cost and high-use drugs did not significantly differ (43% versus 75%, respectively; p = 0.098). ADEs associated with high-cost and high-use medications were categorized as mild (15% versus 10%, respectively), moderate (52% versus 50%, respectively), and severe (33% versus 40%, respectively) (p > 0.05).

CONCLUSION

The frequency, severity, and preventability of ADEs in the ICU were not associated with a drug's cost or frequency of use. Monitoring priorities of the critical care pharmacist should not be dictated by cost alone but should include frequency of use and the potential for causing an ADE.

Prescribing errors resulting in adverse drug events: how can they be prevented?

As approximately 19% of medical errors occurring in hospitals are related to medication errors, reduction of these is one of the major goals to be achieved by healthcare providers. Medication errors may occur at different levels: i) prescribing; ii) transcription; iii) dispensing; and iv) administration. Whereas errors in transcription can be significantly reduced by computerised physician order systems, improvement of prescribing appears to be a much larger problem. Continuous support by ward pharmacists may be feasible in some hospitals, but not in the setting of ambulatory prescribing. Much hope relies on computerised physician order systems with a knowledge database for interactions, warnings on allergies and other intelligent alerts. However, these systems still have some shortcomings and it has not yet convincingly been shown that the use of this technology really improves patient safety.

Unerwünschte Arzneimittelwirkungen

Adverse drug reactions (ADR) occur in about 5% of all pharmacologically treated patients. Between 2% and 20% of all hospital admissions are caused by ADR, and approximately 10% of all hospitalized patients experience ADR during their hospital stay. Several thousand patients die due to ADR in Germany each year. ADR-associated drugs come predominantly from the class of non-steroidal antiinflammatory drugs, anticoagulants, acetylsalicylic acid and cardiovascular drugs. Most ADR cases present as gastrointestinal bleeding and adverse cardiovascular effects. Apart from this, one or more drugs are withdrawn from the market each year because of unwanted but mostly rare side effects. In recent years the most prominent cases were rofecoxib, cisapride and cerivastatin. Physicians in Germany are obliged to report ADR. A substantial proportion of ADR, however, is not reported because it is deemed to be either too well known or the association between the drug and the adverse effect is too doubtful. In some cases, histopathological findings are needed to determine the diagnosis of ADR. Accordingly, physicians should inform the pathologist whether an ADR is suspected and which drugs may be responsible.

Accuracy of adverse-drug-event reports collected using an automated dispensing system

PURPOSE

The accuracy of adverse-drug-event (ADE) reports collected using an automated dispensing system was evaluated.

METHODS

ADE reports were collected by requiring nurses on five units in a tertiary care facility to select a reason for removing two tracer drugs (dextrose injection 50% [D50] and naloxone) from an automated dispensing system (Medstation 2000, Pyxis, San Diego, CA). The accuracy of the ADE reports during a period of 4.5 months was evaluated through retrospective chart review. The sensitivity, specificity, positive predictive value, and negative predictive value of the reports were calculated.

RESULTS

A review of 61 D50 transactions found that the appropriate reason for removal was selected by nursing staff 62% of the time. Twenty-seven transactions were recorded as occurring due to an ADE, and 70% of these were confirmed in the medical record. The sensitivity and specificity of the ADE reports for D50 were 55.9% (95% confidence interval [CI], 39.2-72.6%) and 70.4% (95% CI, 53.2-87.6%), respectively. A review of 32 naloxone transactions found that nurses correctly selected the reason for removal 88% of the time. Twenty-three transactions were recorded as occurring due to an ADE, and 87% of these were confirmed in the medical record. The sensitivity and specificity of the ADE reports for naloxone were 95.2% (95% CI, 86.1-104.4%) and 72.7% (95% CI, 46.4-99.1%), respectively.

CONCLUSION

A Pyxis ADE reporting mechanism using the tracer drugs D50 and naloxone increased the overall reporting of ADEs.

The role of hospital and community pharmacists in pharmacovigilance

In this paper, we give an overview of the role pharmacists actually have and could have in collecting reports of adverse drug reactions (ADRs) and more widely in pharmacovigilance. In the literature, several ways are mentioned in which the pharmacist, both the community pharmacist and the hospital pharmacist, can contribute to the safe use of drugs. In addition to their responsibilities regarding drug dispensing and compliance, they can have a substantial role in ADR reporting. Especially, hospital pharmacists can play a significant role in ADR reporting because the most serious adverse drug events occur in hospitals, and ADRs account for a substantial proportion of hospital admissions. Community pharmacists, however, can also play an important role in ADR reporting. This is, for example, the case in the Netherlands where community pharmacists contribute substantially, both in numbers and in quality of ADR reports. The contribution of the pharmacist to pharmacovigilance should, however, not be limited to ADR reporting. The various pharmaceutical disciplines could also greatly enhance our understanding of the nature of ADRs. If those involved in pharmaceutical disciplines can rise to this challenge, they will significantly help deepen our insights into ADRs.

Hospital-based intensive monitoring of antibiotic-induced adverse events in a university hospital

Hospital-based monitoring is one of the methods used to collect data about drug prescriptions and adverse events. The aim of this 20-day observational prospective study was to evaluate the frequency and type of adverse reaction to antibiotics, and predisposing risk factors in inpatients in six departments of a university hospital (ophthalmology, paediatrics, internal medicine, general surgery, infectious diseases, anaesthesiology and intensive care). The data on all inpatients undergoing antibiotic treatment were collected by physicians trained by our team and validated by an expert panel. Data were recorded on pre-formatted confidential cards (MIO-card). In the 171 inpatients evaluated (125 adults: 39.5% male, mean age 61.6 years, range 21-93; and 46 children: 50% male; mean age 4.75 years, range 3 months-12 years), cefazolin (19.9%), chloramphenicol (18.6%), ceftriaxone (15.4%) and netilmicin (12.9%) were the most frequently used antibiotics. Adverse events occurred in four adults and three children: one had leucopenia (trimethoprim/sulfamethoxazole), one nephrotoxicity (netilmicin+teicoplanin) and one nephrotoxicity (cefotaxime), one diarrhoea (ceftriaxone), one neurotoxicity (isoniazid), one angioneurotic oedema (piperacillin) and one skin rashes (ceftriaxone). A number of strategies (educative and persuasive, facilitative and restrictive) have been proposed to improve antibiotic use. Our study suggests that hospital-based monitoring is a good method with which to detect links between drug exposure and adverse drug reactions in children and adults.

Detecting Adverse Drug Reactions on Paediatric Wards

BACKGROUND

Adverse drug reactions (ADRs) contribute significantly to patient morbidity and mortality, as well as to costs for healthcare systems. Our aim was to evaluate the type and incidence of ADRs in a paediatric hospital population, comparatively ascertained by two different methodological approaches.

METHODS

Our prospective study enrolled all patients admitted to two of the general children wards (46 beds) and the paediatric intensive care unit (6 beds) at the HELIOS Klinikum Wuppertal teaching hospital in Germany, over the study period of 3 months. We used two methods to detect ADRs. The intensified surveillance system relied on a trained physician conducting ward rounds and assessing patient charts. The computer-assisted screening of pathological laboratory parameters used values slightly below or above the age-specific normal range as a trigger signal for a potential ADR, which was subsequently assessed by trained personnel.

RESULTS

By applying both methods simultaneously we observed that 14.1% of children experienced an ADR while they were hospitalised and 2.7% of children were admitted to hospital because of the ADR. Intensified surveillance resulted in the detection of 101 ADRs in 11.9% of patients, predominantly presenting with gastrointestinal symptoms, skin and CNS disorders; computer-assisted screening identified 45 ADRs in 5.7% of patients, mainly with drug-induced blood dyscrasia and liver damage. Furthermore, the ADRs detected by the intensified method were more severe, affected younger children and showed a closer causal attributability to the reaction than the ADRs observed by the computerised method. The spectra of drugs involved were similar, with the anti-infectives being suspected most frequently. The sensitivities of the intensified surveillance system and the computerised surveillance screening came to 67.2% and 44.8%, respectively, with computer-assisted screening having a specificity of 72.8%. The mean positive predictive value of the pathological laboratory values under surveillance by computer-assisted screening was 18.6%. Approximately 25% of ADR-related drugs administered were used for off-label indications.

CONCLUSION

Using the published literature for comparison, we found that ADRs occur as frequently in paediatric patients as in adult patients. Intensified surveillance and computerised surveillance applied in the paediatric setting show substantial differences in their detection specificities. A higher number of and more severe ADRs can be detected by intensified surveillance than by computerised surveillance, but require higher personnel resources.

Implementation of a computer-assisted monitoring system for the detection of adverse drug reactions in gastroenterology

AIM

To investigate the effectiveness of a computer monitoring system that detects adverse drug reactions (ADRs) by laboratory signals in gastroenterology.

METHODS

A prospective, 6-month, pharmaco-epidemiological survey was carried out on a gastroenterological ward at the University Hospital Erlangen-Nuremberg. Two methods were used to identify ADRs. (i) All charts were reviewed daily by physicians and clinical pharmacists. (ii) A computer monitoring system generated a daily list of automatic laboratory signals and alerts of ADRs, including patient data and dates of events.

RESULTS

One hundred and nine ADRs were detected in 474 admissions (377 patients). The computer monitoring system generated 4454 automatic laboratory signals from 39 819 laboratory parameters tested, and issued 2328 alerts, 914 (39%) of which were associated with ADRs; 574 (25%) were associated with ADR-positive admissions. Of all the alerts generated, signals of hepatotoxicity (1255), followed by coagulation disorders (407) and haematological toxicity (207), were prevalent. Correspondingly, the prevailing ADRs were concerned with the metabolic and hepato-gastrointestinal system (61). The sensitivity was 91%: 69 of 76 ADR-positive patients were indicated by an alert. The specificity of alerts was increased from 23% to 76% after implementation of an automatic laboratory signal trend monitoring algorithm.

CONCLUSION

This study shows that a computer monitoring system is a useful tool for the systematic and automated detection of ADRs in gastroenterological patients.

Detection of drug-related adverse events in hospitals

Adverse drug events (ADEs) contribute significantly to patient morbidity and mortality as well as to cost for healthcare providers and society. Since only serious ADEs will result in hospitalisation, the evaluation of ADEs leading to hospitalisation reflects safety and appropriateness of ambulatory prescribing. ADEs occurring during hospitalisation may result from the special clinical situation of hospitalised patients; high degree of severity of diseases (e.g., renal failure, necessity of intensive care) and specific drugs administered only in hospitals. Moreover, the number of diagnostic and therapeutic procedures carried out daily puts the hospitalised patient at an extremely high risk for ADEs.

The cost of adverse drug reactions

In addition to their impact on human health, adverse drug reactions (ADRs) also have significant impact on healthcare costs. These costs are essentially hospital costs, in particular arising from an increase in length of stay caused by an ADR. Although it has been estimated that the occurrence of an ADR during hospitalisation or leading to hospitalisation is responsible for a cost of approximately EURO2800, several studies have also pointed out that the structure of ADR cost is heterogeneous, a factor which must be taken into account when developing preventive strategies. ADR cost evaluation remains difficult from a methodological point of view given that most studies have only evaluated the direct cost. Because of the substantial annual estimated cost of ADRs in industrialised countries, it is necessary to implement preventive programmes, with different strategies consisting of: educational programmes; identifying risk groups; implementing good drug practice; and clinical and laboratory monitoring for ADRs. Promoting pharmacoeconomic studies and co-operation between clinicians, medical pharmacologists and pharmacists remains the key factor for preventing ADRs and decreasing their costs.