Abstract 15875: Real-World Comparative Effectiveness and Safety of Rivaroxaban and Warfarin in Nonvalvular Atrial Fibrillation Patients
Background: Previous clinical trial has demonstrated that rivaroxaban is non-inferior to warfarin for preventing stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF).
Objective: To assess real-world effectiveness, safety, and persistence of rivaroxaban and warfarin in NVAF patients.
Methods: Healthcare claims from Source Healthcare Analytics’ Source Lx database from 5/2011-7/2012 were analyzed. Patients ≥18 year of age, newly initiated on rivaroxaban or warfarin, with ≥2 AF diagnoses (ICD-9-CM: 427.31) without valvular involvement, and a CHADS2 score ≥1 during the 180-day baseline period were included. Cohorts were matched 1:4 using propensity score methods. Study outcomes were major bleeding, gastrointestinal bleeding, composite thrombosis outcomes (ischemic stroke, hemorrhagic stroke, systemic embolism), and venous thromboembolism events. Cox proportional hazard models were used to compare the rates of event and discontinuation (refill gap of 60 days).
Results: The matched sample included 3,654 rivaroxaban and 13,876 warfarin patients. Matching was adequate, with all standardized differences in patient characteristics <10%. Mean age of both cohorts was 73 years; 51% were female; CHADS2 was 2.0; HASBLED was 1.9. The mean (SD) drug exposure for the rivaroxaban and warfarin cohorts was 83 (58.0) and 114 (70.2) days, respectively. No significant differences on any effectiveness or safety outcome were observed (Table). At 3 months, 85% of rivaroxaban patients and 76% warfarin group were persistent with therapy. The risk of treatment discontinuation was significantly lower for rivaroxaban than warfarin users (hazard ratio: 0.66; 95%CI: 0.60-0.72, p<0.001).
Conclusion: This analysis suggests that rivaroxaban and warfarin do not differ significantly in real-world effectiveness and safety, and rivaroxaban is associated with significantly higher treatment persistence.
- © 2013 by American Heart Association, Inc.