Drug-related mortality among inpatients: a retrospective observational study

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.

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.

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.

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.