Factors associated with adverse drug reactions in older inpatients in teaching hospital

Background Adverse drug reactions (ADRs) occur frequently during hospital stays and are an important public health problem, particularly in the care of the older. Objectives This study aimed to determine the prevalence of ADRs among older inpatients and the factors associated with their occurrence. Setting Brazilian teaching hospital. Methods This was a cross-sectional study with older inpatients in the internal medicine ward of a teaching hospital. The dependent variable was the occurrence of an ADR during hospitalization. The independent variables were gender, age, length of hospitalization, number of health problems, medications, and potentially inappropriate medications for the older. Logistic regression was performed to analyze the association between an ADR and the independent variables. Main outcome measure Factors associated with ADR in older inpatients. Results Among the 237 inpatients investigated, 50 (21.1%) developed at least one ADR. The total number of ADRs observed was 62 and the most frequent were acute kidney injury, hypotension, and cutaneous adverse reactions A multivariate analysis demonstrated a positive and independent association between the occurrence of an ADR and the presence of heart failure [odds ratio (OR) 2.4; 95% confidence interval (CI) 1.2–4.6], and with hospitalization time exceeding 12 days (OR 2.3; 95% CI 1.2–4.4). Conclusions The study showed a high prevalence of ADRs among the older and a positive association with hospitalization time and heart failure. Understanding the factors associated with the occurrence of ADRs among older inpatients provides elements for improving the safety of care and optimization of pharmacotherapy.