Drug-related mortality among inpatients: a retrospective observational study

Abstract

Purpose: Hospital mortality related to adverse drug reactions (ADRs) is a relevant clinical problem with major health and economic consequences. We conducted a study to assess hospital mortality related to ADRs, the drugs most frequently involved, and the possible risk factors associated with fatal ADRs.

Methods: A retrospective observational study was conducted, reviewing the clinical records of 1388 consecutive adult patients (18-101 years) who died during a 22-month period in a tertiary hospital in Southern Europe (Granada, Spain). The main outcome was the prevalence of hospital death suspected to be related to administered drugs.

Results: Out of the 1388 adult deaths studied, 256 (18.4 %) were suspected of being related to drugs. Drugs were suspected of causing death in 146 inpatients (10.5 %) and contributing to death in 110 (7.9 %). Drugs related to death were administered during the hospital stay in 161 cases (11.5 %) and before hospital admission in 95 (6.84 %). The most frequent fatal ADRs were cardiac arrhythmia, gastrointestinal bleeding, and respiratory failure. The drugs most frequently involved in fatal ADRs were antithrombotics (anticoagulants or antiplatelets) (23 %), psychotropic drugs (21.2 %), and digoxin (11.3 %). Independent risk factors for ADR-related death were the presence of ≥4 diseases (OR = 1.43) and the receipt of ≥10 drugs (OR = 3.24), but no significant association with gender or age was found.

Conclusions: A high percentage of hospital deaths were suspected of being associated with ADRs, especially in patients with comorbidity and/or polypharmacy. Antithrombotics, psychotropics, and digoxin were the drugs most frequently associated with in-hospital drug-related deaths.

Keywords: Adverse drug reactions; Epidemiology; Hospital mortality; Inpatients.