Abstract 17220: Treatment Persistence and Discontinuation With Rivaroxaban, Dabigatran and Warfarin for Stroke Prevention in Patients With Non-valvular Atrial Fibrillation

Abstract

Introduction: Continuous use of oral anticoagulant (OAC) therapy is essential for reducing the risk of stroke in patients with non-valvular atrial fibrillation. To date, no single study has compared persistence and discontinuation rates between rivaroxaban, dabigatran and warfarin users. Hypothesis: To compare persistence and discontinuation rates between rivaroxaban, dabigatran and warfarin users with non-valvular atrial fibrillation. Methods: A retrospective cohort analysis of the United States MarketScan claims databases was performed. This included adult patients newly initiated on rivaroxaban, dabigatran or warfarin between 1 November 2011 and 31 December 2013 with a baseline CHA2DS2-VASc score ≥2, ≥2 atrial fibrillation diagnosis codes (427.31) and ≥6 months of continuous medical and pharmacy benefits prior to OAC initiation (index date). Propensity score matching was performed in a two-step process to match patients on rivaroxaban with dabigatran 1:1 and with warfarin 1:1. Patients were followed until the earliest of in-hospital death, end of continuous enrolment or end of study period. Persistence was defined as absence of refill gap of >60 days. Discontinuation was defined as no additional refill for >90 days and through end of follow-up. Cox proportional hazards models were estimated to examine hazard ratios (HRs) of OAC non-persistence and discontinuation. Results: A total of 32,634 patients were included (N=10,878/OAC group). At 3 months’ follow-up, treatment persistence was 79.2%, 69.6% and 70.9% for rivaroxaban, dabigatran and warfarin users, respectively, dropping to 70.2%, 57.8% and 58.8% after 6 months, 60.1%, 44.7% and 42.0% after 1 year and 50.4%, 30.6% and 26.5% after 2 years. On regression, rivaroxaban use was associated with a decreased hazard of non-persistence compared with dabigatran (HR=0.64; 95% confidence interval [CI] 0.62-0.67) and warfarin (HR=0.62; 95% CI 0.59-0.64), and a decreased rate of discontinuation versus dabigatran (HR=0.61; 95% CI 0.58-0.64) and warfarin (HR=0.65; 95% CI 0.62-0.68). Conclusions: This matched patient analysis indicated significantly higher persistence and lower discontinuation rates with rivaroxaban compared with dabigatran and warfarin.