Prevalence of urgent hospitalizations caused by adverse drug reactions: a cross-sectional study

Adverse drug reactions account for a substantial portion of emergency hospital admissions. However, in the last decade, few studies have been conducted to determine the prevalence of hospitalization due to adverse drug reactions. Therefore, this cross-sectional study was conducted to determine the proportion of adverse drug reactions leading to emergency hospital admission and to evaluate the risk factors for these reactions. A total of 5707 consecutive patients aged > 18 years who were emergently hospitalized due to acute medical illnesses between June 2018 and May 2021 were included. Causality assessment for adverse drug reactions was performed by using the World Health Organization-Uppsala Monitoring Centre criteria. The median patient age was 78 years (IQR 63-87), and the proportion of women was 47.9%. Among all the hospitalizations, 287 (5.0%; 95% confidence interval (CI) 4.5-5.6%) were caused by 368 adverse drug reactions. The risk factors independently associated with hospitalization due to adverse drug reactions were polypharmacy (OR 2.66), age >= 65 years (OR 2.00), and ambulance use (OR 1.41). Given that the population is rapidly aging worldwide, further efforts are needed to minimize hospitalizations caused by adverse drug reactions.