Prevalence and Impact of Fall-Risk-Increasing Drugs, Polypharmacy, and Drug-Drug Interactions in Robust Versus Frail Hospitalised Falls Patients: A Prospective Cohort Study

Background Several measures of medication exposure are associated with adverse outcomes in older people. Exposure to and the clinical outcomes of these measures in robust versus frail older inpatients are not known. Objective In older robust and frail patients admitted to hospital after a fall, we investigated the prevalence and clinical impact of fall-risk-increasing drugs (FRIDs), total number of medications, and drug-drug interactions (DDIs). Methods Patients >= 60 years of age admitted with a fall to a tertiary referral teaching hospital in Sydney were recruited and frailty was assessed. Data were collected at admission, discharge, and 2 months after admission. Results A total of 204 patients were recruited (mean age 80.5 +/- 8.3 years), with 101 robust and 103 frail. On admission, compared with the robust, frail participants had significantly higher mean +/- SD number of FRIDs (frail 3.4 +/- 2.2 vs. robust 1.6 +/- 1.5, P < 0.0001), total number of medications (9.8 +/- 4.3 vs. 4.4 +/- 3.3, P < 0.0001), and DDI exposure (35 vs. 5 %, P = 0.001). Number of FRIDs on discharge was significantly associated with recurrent falls [odds ratio (OR) 1.7 (95 % confidence interval [CI] 1.3-2.1)], which were most likely to occur with 1.5 FRIDs in the frail and 2.5 FRIDs in the robust. Number of medications on discharge was also associated with recurrent falls [OR 1.2 (1.0-1.3)], but DDIs were not. Conclusion Exposure to FRIDs and other measures of high-risk medication exposures is common in older people admitted with falls, especially the frail. Number of FRIDs and to a lesser extent total number of medicines at discharge were associated with recurrent falls.