Patient characteristics associated with the initiation of novel oral anticoagulants versus warfarin in patients with atrial fibrillation

Abstract

Purpose: Oral anticoagulants including warfarin and novel oral anticoagulants (NOACs) are recommended for stroke prevention in patients with atrial fibrillation (AF). It is important to understand how patients receiving NOACs may differ from those receiving warfarin in the real-world clinical setting. The purpose of this study is to assess clinical and demographic characteristics associated with NOAC initiation versus warfarin in AF patients. Methods: Newly-initiating oral anticoagulant users with AF were identified from a national database of medical and pharmacy insurance claims in the United States. Patients were included in the study if they newly initiated warfarin or a NOAC (dabigatran and rivaroxaban) between November 2010 and December 2011. Individuals with valvular heart disease and those treated with oral anticoagulants in the year prior to initiation were excluded. Comorbid conditions (hypertension, diabetes and history of congestive heart failure (CHF), myocardial infarction (MI), stroke, and bleeding) were obtained from claims history in the year prior to initiation. Factors associated with NOAC initiation were examined using multivariate logistic regression. Results: A total of 10,789 NOAC patients and 19,964 warfarin patients were included in this study. NOAC users were younger than warfarin users (mean age 69 vs. 71 years, p <55], females [OR=0.90 (0.86, 0.95)], and in those with diabetes [OR=0.92 (0.86, 0.98)] or hypertension [OR=0.99 (0.93, 1.048)]. NOAC use was also significantly less likely in those with history of GI bleeding [OR=0.79 (0.70, 0.89)], intracranial hemorrhage [OR= 0.62 (0.46, 0.83)], other bleeding [OR=0.68 (0.62, 0.74)], stroke [OR=0.89 (0.83, 0.95)], CHF [OR=0.71 (0.67, 0.75)], or MI [OR=0.79 (0.72, 0.87)]. Conclusions: In a commercially insured population in the United States, NOAC users were younger and had significantly fewer comorbid conditions including history of MI, stroke and bleeding compared to warfarin patients. Further research is warranted as additional data becomes available to examine changes in anticoagulant treatment patterns over time and factors associated with specific NOAC initiation.