A multicenter record review of in-hospital adverse drug events requiring a higher level of care

Objective: Adverse drug events (ADEs) are a worldwide concern, particularly when leading to a higher level of care. This study defines a higher level of care as an unplanned (re)admission to an intensive care unit or an intervention by a Medical Emergency Team. The objectives are to describe the incidence and preventability of ADEs leading to a higher level of care, to assess the types of drug involved, and to identify the risk factors. Methods: A three-stage retrospective review was performed in six Belgian hospitals. Patient records were assessed by a trained clinical team consisting of a nurse, a physician, and a clinical pharmacist. Descriptive statistics, univariate, and multiple logistic regressions were used. Results: In this study, 830 patients were detected for whom a higher level of care had been needed. In 160 (19.3%) cases, an ADE had occurred; 134 (83.8%) of these were categorized as preventable adverse drug events (pADEs). The overall incidence rate of patients transferred to a higher level of care because of a pADE was 33.9 (95% CI: 28.5-39.3) per 100,000 patient days at risk. Antibiotics and antithrombotic agents accounted both for one-fifth of all pADEs. Multivariate analysis indicated American Society of Anaesthesiologists physical status score as a risk factor for pADEs. Conclusions: The high number of pADE with patient harm shows that there is a need for structural improvement of pharmacotherapeutic care. Detection of these pADEs can be the basis for the implementation of these improvements.