Epidemiology of drug‐related deaths in European hospitals: A systematic review and meta‐analysis of observational studies

Aims To perform a systematic review of observational studies on the epidemiology of drug‐related death (DRD) in patients requiring hospitalisation or while hospitalised (hospital‐acquired DRD). Methods We conducted a systematic review of observational studies investigating the occurrence rate of DRD episodes among deceased inpatients. Two independent researchers assessed eligibility criteria, extracted data and evaluated the risk of bias. Both quality assessment and meta‐analysis were performed. Results From 1351 identified potential studies, 6 retrospective studies were included. DRD occurrences rates were 7.3% (95% confidence interval [CI] 4.1–12.5) among deceased inpatients and 0.13% (95% CI 0.04–0.40) among hospitalised patients. During hospitalisation, acquired‐DRD represented 2.7% (95% CI 1.0–6.9) of inpatient deaths and occurred in 0.05% (95% CI 0.01–0.23) of hospitalised patients. However, these estimates have to be viewed with caution because there was significant heterogeneity (I2 > 97%). None of the studies were considered to be at high risk of bias according to the criteria of the NIH Quality Assessment Tool. The most common adverse drug reactions related to death were haemorrhages due to antithrombotic drugs (39%, 95% CI 26.5–53.2) and infections in drug‐immunosuppressed patients (27.5%, 95% CI 16.7–41.7). Conclusion We found that the DRD occurrence rate of deceased hospital inpatients has been infrequently studied in Europe. Our findings suggest that drugs are an important cause of death in hospitals. The limited number of studies in European countries stresses the need for more research in this area.