Predictors of fracture while on treatment with oral bisphosphonates: a population-based cohort study.

Although oral bisphosphonates (BPs) are highly effective in preventing fractures, some patients will fracture while on treatment. We identified predictors of such fractures in a population-based cohort of incident users of oral BPs. We screened the Sistema d'Informació per al Desenvolupament de l'Investigació en Atenció Primària (SIDIAP) database to identify new users of oral BPs in 2006-2007. SIDIAP includes pharmacy invoice data and primary care electronic medical records for a representative 5 million people in Catalonia (Spain). Exclusion criteria were the following: Paget disease; 6 months of therapy. Incidence of fracture while on treatment was 3.4/100 person-years (95% confidence interval [CI], 3.1-3.7). Predictors of these among patients persisting and adhering to treatment included: older age (subhazard ratio [SHR] for 60 to