Abstract 15620: Adherence With Dabigatran Therapy in Patients With Atrial Fibrillation
Background: Dabigatran is a novel oral anticoagulant approved recently for stroke prevention in atrial fibrillation (AF). Although dabigatran is more convenient than warfarin, its lack of monitoring and twice daily dosing may predispose patients to nonadherence. In the RE-LY study, 15% of patients discontinued dabigatran at 1 year of follow-up, however, discontinuation rates for dabigatran in clinical practice are unknown.
Methods: We conducted a population-based cohort study using administrative data of patients with AF, linking between hospital discharge databases and prescription drug claims in Quebec, Canada from April 2011 to March 2012. Adherence was measured as proportion of patients discontinuing dabigatran and time to discontinuation within the first 6 months of therapy. Discontinuation was defined as a gap in dabigatran prescriptions for 14 or more days. A multivariate Cox proportional hazards model was used to identify potential predictors of discontinuation.
Results: The cohort consisted of 10,644 dabigatran users, 5,922 patients taking 110mg bid and 4,722 taking 150mg bid. Median follow-up was 163 days. During this time, 25.7% of patients discontinued dabigatran (110mg: 26.5%; 150mg: 24.6%), with a median time to discontinuation of 64 days (110mg: 62 days; 150mg: 70 days). Among those who discontinued, 35.1% switched to warfarin after a median of 54 days of therapy. Increasing age predicted discontinuation (HR 1.007, 95% CI 1.002,1.012) while prior warfarin use predicted continued dabigatran use (HR 0.86, 95% CI 0.78, 0.95).
Conclusions: Approximately 1 in 4 patients discontinues dabigatran within 6 months, among whom, about a third switches to warfarin therapy. Dabigatran discontinuation rates in clinical practice are higher than those reported in the RE-LY clinical trial, and are higher in older patients and warfarin naïve patients.
- © 2013 by American Heart Association, Inc.