Risk factors predictive of adverse drug events and drug-related falls in aged care residents: secondary analysis from the ReMInDAR trial

Background Residents of aged-care facilities have high rates of adverse drug events. This study aimed to identify risk factors for adverse drug events in aged-care residents. Method This was a secondary study using data from a multicentre randomised controlled trial. Data from 224 residents for whom there was 6 months of baseline information were analysed. We assessed the risk of adverse drug events and falls (post hoc) in the subsequent 6 months. Adverse events were identified via a key word search of the resident care record and adjudicated by a multidisciplinary panel using a modified version of the Naranjo criteria. Covariates identified through univariable logistic regression, including age, sex, medicines, physical activity, cognition (Montreal Cognitive Assessment), previous adverse events and health service use were included in multivariable models. Results Overall, 224 residents were included, with a mean age of 86 years; 70% were female. 107 (48%) residents had an adverse drug event during the 6-month follow-up. Falls and bleeding were experienced by 73 (33%) and 28 (13%) residents, respectively. Age (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.01–1.10), weight (OR 1.02, 95% CI 1.002–1.04), previous fall (OR 2.58, 95% CI 1.34–4.98) and sedative or hypnotic medicine use (OR 1.98, 95% CI 1.52–2.60) were associated with increased risk of adverse drug events. Increased cognition (OR 0.89, 95% CI 0.83–0.95) was protective. Risk factors for falls were previous fall (OR 3.27, 95% CI 1.68–6.35) and sedative or hypnotic medicines (OR 3.05, 95% CI 1.14–8.16). Increased cognition (OR 0.88, 95% CI 0.83–0.95) was protective. Conclusion Our results suggest residents with a previous fall, reduced cognition, and prescription of sedative or hypnotic medicines were at higher risk of adverse drug events and should be considered for proactive prevention.