Background: No studies have directly compared the effectiveness and safety of dabigatran and rivaroxaban using US Medicare data.
Objective: Our objective was to compare effectiveness and safety between rivaroxaban 20 mg/dabigatran 150 mg and rivaroxaban 15 mg/dabigatran 75 mg among patients with atrial fibrillation (AF).
Methods: Using 2010-2013 US Medicare Part D data, we selected patients with AF initiating dabigatran 150/75 mg or rivaroxaban 20/15 mg between 4 November 2011 (when rivaroxaban was approved) and 31 December 2013. Our sample included 7322 patients receiving dabigatran 150 mg, 5799 patients receiving rivaroxaban 20 mg, 1818 receiving dabigatran 75 mg, and 2568 receiving rivaroxaban 15 mg. We followed them until stroke, other thromboembolic events, bleeding, discontinuation or switch of an anticoagulant, death, or 31 December 2013. We constructed Cox proportional hazard models with propensity score weighting to compare clinical outcomes between groups.
Results: There was no difference in the risk of stroke between dabigatran 150 mg and rivaroxaban 20 mg (hazard ratio [HR] 1.05; 95 % confidence interval [CI] 0.97-1.13) or between dabigatran 75 mg and rivaroxaban 15 mg (HR 1.05; 95 % CI 0.94-1.18). Compared with dabigatran 150 mg, rivaroxaban 20 mg was associated with a higher risk of other thromboembolic events (HR 1.28; 95 % CI 1.14-1.44), major bleeding (HR 1.32; 95 % CI 1.17-1.50), and death (HR 1.36; 95 % CI 1.19-1.56). The risk of thromboembolic events other than stroke (HR 1.37; 95 % CI 1.15-1.62), major bleeding (HR 1.51; 95 % CI 1.25-1.82), and death (HR 1.21; 95 % CI 1.04-1.41) was also higher for rivaroxaban 15 mg than for dabigatran 75 mg.
Conclusions: There was no difference in stroke prevention between rivaroxaban and dabigatran; however, rivaroxaban was associated with a higher risk of thromboembolic events other than stroke, death, and bleeding.