1. Non-warfarin oral anticoagulant copayments and adherence in atrial fibrillation: A population-based cohort study.
- Author
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Rome BN, Gagne JJ, Avorn J, and Kesselheim AS
- Subjects
- Anticoagulants economics, Anticoagulants therapeutic use, Antithrombins economics, Antithrombins therapeutic use, Cohort Studies, Dabigatran economics, Dabigatran therapeutic use, Databases, Factual statistics & numerical data, Deductibles and Coinsurance statistics & numerical data, Drug Costs, Factor Xa Inhibitors economics, Factor Xa Inhibitors therapeutic use, Female, Humans, Male, Medicare Part C statistics & numerical data, Middle Aged, Pyrazoles economics, Pyrazoles therapeutic use, Pyridines economics, Pyridines therapeutic use, Pyridones economics, Pyridones therapeutic use, Rivaroxaban economics, Rivaroxaban therapeutic use, Sample Size, Stroke etiology, Thiazoles economics, Thiazoles therapeutic use, United States, Warfarin economics, Warfarin therapeutic use, Atrial Fibrillation complications, Deductibles and Coinsurance economics, Medication Adherence statistics & numerical data, Stroke prevention & control
- Abstract
Background: In patients with atrial fibrillation, incomplete adherence to anticoagulants increases risk of stroke. Non-warfarin oral anticoagulants (NOACs) are expensive; we evaluated whether higher copayments are associated with lower NOAC adherence., Methods: Using a national claims database of commercially-insured patients, we performed a cohort study of patients with atrial fibrillation who newly initiated a NOAC from 2012 to 2018. Patients were stratified into low (<$35), medium ($35-$59), or high (≥$60) copayments and propensity-score weighted based on demographics, insurance characteristics, comorbidities, prior health care utilization, calendar year, and the NOAC received. Follow-up was 1 year, with censoring for switching to a different anticoagulant, undergoing an ablation procedure, disenrolling from the insurance plan, or death. The primary outcome was adherence, measured by proportion of days covered (PDC). Secondary outcomes included NOAC discontinuation (no refill for 30 days after the end of NOAC supply) and switching anticoagulants. We compared PDC using a Kruskal-Wallis test and rates of discontinuation and switching using Cox proportional hazards models., Results: After weighting patients across the 3 copayment groups, the effective sample size was 17,558 patients, with balance across 50 clinical and demographic covariates (standardized differences <0.1). Mean age was 62 years, 29% of patients were female, and apixaban (43%), and rivaroxaban (38%) were the most common NOACs. Higher copayments were associated with lower adherence (P < .001), with a PDC of 0.82 (Interquartile range [IQR] 0.36-0.98) among those with high copayments, 0.85 (IQR 0.41-0.98) among those with medium copayments, and 0.88 (IQR 0.41-0.99) among those with low copayments. Compared to patients with low copayments, patients with high copayments had higher rates of discontinuation (hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.08-1.19; P < .001)., Conclusions: Among atrial fibrillation patients newly initiating NOACs, higher copayments in commercial insurance were associated with lower adherence and higher rates of discontinuation in the first year. Policies to lower or limit cost-sharing of important medications may lead to improved adherence and better outcomes among patients receiving NOACs., Competing Interests: Disclosures BNR has received consulting fees from Blue Cross Blue shield of Massachusetts and the non-profit Alosa Health for unrelated work. JJG has received salary support from grants from Eli Lilly and Company and Novartis Pharmaceuticals Corporation to the Brigham and Women's Hospital and was a consultant to Optum, Inc., all for unrelated work. The other authors have no conflicts of interest to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2021
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