title: Comparing Stroke and Bleeding with Rivaroxaban and Dabigatran in Atrial Fibrillation: Analysis of the US Medicare Part D Data.
abstract: 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.
authors.affiliation: Department of Pharmacy and Therapeutics, School of Pharmacy, University of Pittsburgh, 3501 Terrace St, Pittsburgh, PA, 15261, USA.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Hernandez
authors.affiliation: Department of Health Policy and Management, Graduate School of Public Health, University of Pittsburgh, 130 De Soto Street, Crabtree Hall A664, Pittsburgh, PA, 15261, USA. ytzhang@pitt.edu.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000453:epidemiology; D000069604:Dabigatran / Q000009:adverse effects / Q000627:therapeutic use*; D065427:Factor Xa Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects / Q000627:therapeutic use; D006470:Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D008297:Male; D054524:Medicare Part D / Q000706:statistics & numerical data; D000069552:Rivaroxaban / Q000009:adverse effects / Q000627:therapeutic use*; D020521:Stroke / Q000453:epidemiology / Q000517:prevention & control*; D014481:United States / Q000453:epidemiology
chemical_list: D065427:Factor Xa Inhibitors; D005343:Fibrinolytic Agents; D000069552:Rivaroxaban; D000069604:Dabigatran