A Real-World Observational Study of Hospitalization and Health Care Costs Among Nonvalvular Atrial Fibrillation Patients Prescribed Oral Anticoagulants in the U.S. Medicare Population.

This article has been corrected. Please see J Manag Care Spec Pharm, 2020;26(5):682

backgroundClinical trials have shown that direct oral anticoagulants (DOACs)-including dabigatran, rivaroxaban, apixaban, and edoxaban-are at least as effective and safe as warfarin for the risk of stroke/systemic embolism (SE) and major bleeding (MB) in patients with atrial fibrillation (AF). However, few studies have compared oral anticoagulants (OACs) among elderly patients.

objectiveTo compare hospitalization risks (all-cause, stroke/SE-related, and MB-related) and associated health care costs among elderly nonvalvular AF (NVAF) patients in the Medicare population who initiated warfarin, dabigatran, rivaroxaban, or apixaban.

methodsPatients (aged ≥ 65 years) initiating warfarin or DOACs (apixaban, rivaroxaban, and dabigatran) were selected from the Centers for Medicare & Medicaid Services database from January 1, 2013, to December 31, 2014. Patients initiating each OAC were matched 1:1 to apixaban patients using propensity score matching to balance demographic and clinical characteristics. Cox proportional hazards models were used to estimate the risk of hospitalization of each OAC versus apixaban. Generalized linear models and two-part models with bootstrapping were used to compare all-cause health care costs and stroke/SE- and MB-related medical costs between matched cohorts.

resultsOf the 264,479 eligible patients, 77,480 warfarin-apixaban, 41,580 dabigatran-apixaban, and 77,640 rivaroxaban-apixaban patients were matched. The OACs were associated with a significantly higher risk of all-cause hospitalization compared with apixaban (warfarin: HR = 1.27, 95% CI = 1.23-1.31,

conclusionsThis real-world study showed that among elderly NVAF patients in the Medicare population, apixaban was associated with significantly lower risks of all-cause, stroke/SE-related, and MB-related hospitalizations compared with warfarin, dabigatran, and rivaroxaban. Accordingly, apixaban showed significantly lower all-cause health care costs and MB-related medical costs. DISCLOSURES: This study was funded by Bristol Myers Squibb and Pfizer. Amin is an employee of the University of California, Irvine, and was a paid consultant to Bristol Myers Squibb in connection with this study and the development of this manuscript. He has served as a consultant and/or speaker for Bristol Myers Squibb, Pfizer, and Boehringer Ingelheim. Keshishian and Zhang are employees of STATinMED Research, a paid consultant to Pfizer and Bristol Myers Squibb in connection with this study and the development of this manuscript. Trocio, Dina, Mardekian, and Liu are employees of Pfizer, with ownership of stocks in Pfizer. Le, Rosenblatt, Nadkarni, and Vo are employees of Bristol Myers Squibb. Rosenblatt and Vo have ownership of stocks in Bristol Myers Squibb. Baser has no conflicts to disclose.