Abstract 15187: Monitoring the Safety and Effectiveness of Dabigatran and Warfarin in Routine Care: An Interim Analysis Using U.S. Healthcare Utilization Data
Background: Depending on dosing regime, dabigatran demonstrated comparable or better safety and efficacy relative to warfarin in randomized trials investigating patients with non-valvular atrial fibrillation but little is known about outcomes in routine care.
Objectives: To generate early evidence of effectiveness and safety of dabigatran compared to warfarin in an active safety monitoring system of patients in routine care.
METHODS: Using US health care utilization data and propensity score matching, we compared new users of dabigatran and warfarin to assess pre-specified stroke and bleeding events.
RESULTS: We identified 4,158 patients with non-valvular atrial fibrillation and CHA2DS2-VASc scores ≥1 who initiated dabigatran, and 7,724 patients who initiated warfarin from October 2010 - June 2012. An interim analysis with a propensity score including known risk factors produced matched groups with nearly identical characteristics: 2,991 dabigatran initiators with 1,237 person-years (PY) follow-up and 2,991 warfarin initiators with 950 PY follow-up. Average age was 63 years and 9% had a recent stroke. Follow-up ended at anticoagulant discontinuation, study event, or insurance disenrollment. Warfarin initiators discontinued earlier and more frequently. There were 36 strokes among dabigatran users vs. 30 among warfarin users (Cox HR=1.05, 95% CI=0.64-1.70), along with 74 major bleedings among dabigatran users vs. 63 in warfarin users (HR=0.97, 0.69-1.36).
Conclusions: In results from this first interim analysis of a sequential cohort study program in routine care, with planned future analyses involving increasing numbers of patients, it appears that dabigatran has effectiveness and safety similar to warfarin. Interpretation of these first results is hampered by a limited cohort size and short follow-up. Future analyses will add additional data sources and analyze subgroups of interest including primary and secondary prevention.
- © 2013 by American Heart Association, Inc.