The Association between Polypharmacy and Hip Fracture in Osteoporotic Women: A Nested Case–Control Study in South Korea

Abstract

Background and Objective: Polypharmacy, regarded as an indicator of potentially inappropriate medications (PIMs), may lead to a higher risk of serious health consequences in elderly patients with osteoporosis. Thus, this study aimed to analyze the association between polypharmacy and hip fracture in patients with osteoporosis because only a limited number of studies have reported on this association, with inconsistent results to date. Methods: In this nested case–control study using a population-based sample cohort, the target cases were female patients with hip fracture diagnosed with osteoporosis and aged ≥ 50 years. Polypharmacy (prescription of an average of five or more daily drugs), PIMs for hip fracture (such as benzodiazepines and glucocorticoids), Charlson Comorbidity Index (CCI) score, and other comorbidities were analyzed during the year preceding the diagnosis of hip fracture. Adjusted odds ratios (ORs) for hip fracture for the variables were also analyzed. Results: The cases (n = 1003) showed higher exposure rates to polypharmacy, glucocorticoids, and benzodiazepines, and had more severe comorbidity statuses compared with the controls. The ORs for hip fracture adjusted for confounders increased with polypharmacy level, with persistent statistical significance in most analyses. The ORs (95% confidence intervals), with reference to the 0 to < 1 drug group, were 1.65 (1.31–2.08) and 2.11 (1.12–3.96) for the 5 to < 10 and 10 + drug groups, respectively, with adjustment for PIMs, and 1.34 (1.04–1.72) and 1.45 (0.76–2.80) for the 5 to < 10 and 10 + drug groups, respectively, with adjustment for PIMs and CCI score. Conclusions: The results suggest that polypharmacy is associated with an increased risk of hip fracture after adjustment for confounders in patients with osteoporosis. These results highlight the importance of polypharmacy management in preventing hip fractures in patients with osteoporosis.