OBJECTIVES: Since 2010, several non-vitamin K antagonist oral anticoagulants (NOACs) have been brought to the U.S. market, yet little is known regarding their evolving adoption for prophylaxis of atrial fibrillation (AF) related stroke. We examined temporal trends in choice of oral anticoagulants (OACs) among incident OAC users with AF and its association with patients’ demographic and clinical characteristics.

METHODS: We conducted a serial cross-sectional analysis of medical and pharmacy claims for commercial and Medicare Advantage enrollees in a large, private, U.S. health plan. We identified 112,187 adults with nonvalvular AF starting OACs between October 2010 and March 2017. Multivariable logistic regression was used to examine the association of patient characteristics with choice of NOACs vs warfarin. Multinomial logistic regression with generalized logit link function was used to test the association of patient characteristics with choice among NOACs.

RESULTS: The use of NOACs has increased dramatically since their introduction in October 2010. In the first quarter of 2017 (2017Q1), 7,502 patients started OACs, of whom 78.9% used NOACs and 21.1% warfarin. For NOACs, 3.8% used dabigatran, 25.0% rivaroxaban, and 50.1% apixaban. In multivariable analyses, factors associated with choice of NOACs vs warfarin included younger age, lower stroke or bleeding risk, fewer comorbidities, higher socioeconomic status, and prescription by cardiologists (all P<0.001). There was no sex difference in likelihood of filling NOACs vs warfarin in 2010Q4-2012 but women had higher odds of starting NOACs (odds ratio=1.19; 95% confidence interval=1.14-1.25) in 2015-2017Q1. Among NOAC users, the odds of apixaban use increased with age, female sex, stroke or bleeding risk, and comorbidities (all P<0.05).

CONCLUSIONS: NOAC use has increased substantially among incident OAC users with nonvalvular AF, predominantly driven by increased use of apixaban. Warfarin and apixaban were generally preferred for elderly, patients with higher stroke or bleeding risk, and those with more comorbidities.