Background: Drug therapy is associated with adverse effects, and fatal adverse drug events (ADEs) have become major hospital problems. Our study assesses the incidence of fatal ADEs in a major medical department and identifies possible patient characteristics signifying fatal ADE risk.
Methods: During a 2-year period, a multidisciplinary study group examined all 732 patients who died--5.2% of the 13992 patients admitted to the Department of Internal Medicine, Central Hospital of Akershus, Nordbyhagen, Norway. Decisions about the presence or absence of fatal ADEs were based on aggregated clinical records, autopsy results, and findings from premortem and postmortem drug analyses.
Results: In 18.2% of the patients (133/732) (95% confidence interval, 15.4%-21.0%), deaths were classified as being directly (64 [48.1%] of 133) or indirectly (69 [51.9%] of 133) associated with 1 or more drugs (this equals 9.5 deaths per 1000 hospitalized patients). Those with fatal ADEs (cases) were older, had more diseases, and used more drugs than those without fatal ADEs (noncases). In 75 of the 133 patients with fatal ADEs, autopsy findings and/or drug analysis data were decisive for recognizing the ADEs; in 62 of the remaining 595 patients, similar data proved necessary to exclude the suspicion of a fatal ADE. Major culprit drugs were cardiovascular, antithrombotic, and sympathomimetic agents.
Conclusions: Fatal ADEs represent a major hospital problem, especially in elderly patients with multiple diseases. A higher number of drugs administered was associated with a higher frequency of fatal ADEs, but whether a high number of drugs is an independent risk factor for fatal ADEs is unsettled. Autopsy results and the findings of premortem and postmortem drug analyses were important for recognizing and excluding suspected fatal ADEs.