Association of Polypharmacy and Anticholinergic Burden with Length of Stay in Hospital Amongst Older Adults Admitted with Hip Fractures: A Retrospective Observational Study

Background Age-associated multimorbidity and polypharmacy, predispose individuals to falls and consequent hip fractures. We examined the impact of polypharmacy (≥ 4 drugs daily), including anticholinergic agents, on hospital length of stay (LOS), mobility within 1-day of hip surgery and pressure ulcers in adults ≥ 60 years admitted with hip fractures. Methods In this retrospective observational study, information on medications at admission was obtained to calculate the total number of drugs taken, including those imposing an anticholinergic burden (ACB). Associations between variables were examined by logistic regression; adjusted for age, sex, co-morbidities, pre-fracture functional limitations and alcohol consumption. Results There were 787 women and 318 men of similar mean age (± SD): 83.1 years (± 8.6) and 82.5 years (± 9.0), respectively. Compared to patients with an ACB score = 0 and taking < 4 drugs daily, those with an ACB score ≥ 1 and taking ≥ 4 drugs daily had greater risk of prolonged LOS (≥ 2 weeks), OR 1.8 (1.2–2.7); failure to mobilise within 1-day of surgery, OR 1.9 (1.1–3.3); and pressure ulcers, OR 3.0 (95% CI 1.2–7.9). LOS was further prolonged by failure to mobilise within 1-day of surgery and/or pressure ulcers. Those with either an ACB score ≥ 1 or the use of ≥ 4 drugs daily had intermediate risks. Conclusions Anticholinergic agents and polypharmacy in patients with hip fractures are associated with longer LOS in hospital, further accentuated by failure to mobilise within 1-day after surgery and pressure ulcers. This study provides further evidence of the impact of polypharmacy, including those with an ACB, on adverse health outcomes and lends support to reduce potentially inappropriate prescribing.