Medication persistence and risk of fracture among female Medicare beneficiaries diagnosed with osteoporosis

We examined the relationship between persistent osteoporosis medication use and fracture risk among female Medicare beneficiaries diagnosed with osteoporosis using Medicare claims, 2009–2012. Persistent use was associated with reduced risk of fracture and significantly lower total health care costs in the follow-up period. Results were consistent using different analytical methods. This study aimed to examine the relationship between medication persistence and fracture risk among female Medicare beneficiaries diagnosed with osteoporosis. Elderly female Medicare beneficiaries diagnosed with osteoporosis and initiated on osteoporosis medication January 1, 2009–June 30, 2011, were included. Persistent medication use was defined as continuous use (no gap ≥ 60 days) for 1 year or longer. The key outcome was fragility fracture. A difference-in-difference analysis was performed at the log scale of fracture rate using a Poisson regression model with months 1–6 before medication initiation as the pre-initiation period and up to 18 months after as the post-initiation period. Total health care costs were compared using a similar approach. Sensitivity analyses were conducted using different pre- and post-initiation periods. The study included 294,369 patients; 32.9% were persistent osteoporosis medication users and 67.1% non-persistent (