Real-world evidence highlighting the risks and benefits of novel oral anticoagulants (NOCAs) is lacking. This study compared major and clinically relevant non-major (CRNM) bleeding risk and costs among non-valvular atrial fibrillation (NVAF) patients newly treated with apixaban, dabigatran, rivaroxaban, or warfarin. A retrospective analysis of NVAF patients newly treated with apixaban, dabigatran, rivaroxaban, or warfarin was conducted using PharMetrics Plus data from 1/ 2012 - 9/ 2014. Patients were indexed on the date of the first anticoagulant prescription, and were required to be ≥18 years old and have CHA
2
DS
2
-VASc score > 0 and ≥ 1 month of follow-up. Patients were followed until discontinuation (≥30-day gap in treatment), treatment switch, end of continuous enrollment, 1 year post-index, or end of study. Major and CRNM bleeding, and bleeding-related costs were measured. Cox proportional hazards model was used to examine the association between anticoagulants and risk of bleeding and GLM was used to evaluate bleeding-related costs. The study included 24,573 NVAF patients; distributed as apixaban 11.7%, dabigatran 12.0%, rivaroxaban 36.7%, and warfarin 39.6%. Mean age was 64.4 and 66.5% were males. HAS-BLED and CHA
2
DS
2
-VASc scores averaged 2.0 and 2.7, respectively. After adjusting for differences in baseline characteristics, when compared to apixaban patients, rivaroxaban (HR: 1.5;
P
=0.0013) and warfarin (HR: 1.7;
P
<0.0001) patients were more likely to have major bleeding, and dabigatran (HR: 1.3;
P
=0.0030), rivaroxaban (HR: 1.7;
P
<0.0001), and warfarin (HR: 1.4;
P
<0.0001) patients were more likely to have CRNM bleeding. Major bleeding risk was similar between apixaban and dabigatran patients. Major and CRNM bleeding costs, when compared to apixaban patients ($154 and $18), were significantly higher for dabigatran ($457;
P
<0.0001 and $39;
P
<0.0001), rivaroxaban ($420;
P
<0.0001 and $61;
P
<0.0001), and warfarin ($511;
P
<0.0001 and $63;
P
<0.0001) patients. Among anticoagulant-naive moderate-to-high risk NVAF patients encountered in real-world clinical setting, major bleeding was lower with apixaban compared to warfarin and rivaroxaban. Bleeding costs were lower with apixaban compared to alternative NOACs and warfarin.
REAL WORLD COMPARISON OF MAJOR BLEEDING RISK AMONG NON-VALVULAR ATRIAL FIBRILLATION PATIENTS NEWLY INITIATED ON APIXABAN, WARFARIN, DABIGATRAN OR RIVAROXABAN: A 1:1 PROPENSITY-SCORE MATCHED ANALYSIS
