Medical Costs of Oral Anticoagulants vs Warfarin for Atrial Fibrillation Patients with Different Stroke Risks.

INTRODUCTION: The Apixaban for the Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE), Randomized Evaluation of Long-term Anticoagulation Therapy (RE-LY), and Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF) trials demonstrated that the oral anticoagulants (OACs), apixaban, dabigatran, and rivaroxaban, respectively, are efficacious for stroke prevention among nonvalvular atrial fibrillation (NVAF) patients. Based on clinical trial results this study evaluated medical costs of clinical events associated with use of individual OACs relative to those of warfarin in NVAF patients with moderate and high stroke risk.

METHODS: Rates for primary and secondary efficacy and safety outcomes (i.e., clinical events) among NVAF patients with CHADS2 = 2 and ≥3 were determined from the three OAC trials. One-year incremental costs among patients with clinical events from a US payer perspective were obtained from the literature and inflation adjusted to 2010 costs. Medical costs for clinical events associated with each OAC vs. warfarin were estimated and compared.

RESULTS: For NVAF patients with moderate stroke risk (CHADS2 = 2) differences in clinical event medical costs vs. warfarin were -$298, -$143, and +$117 per patient year for apixaban, dabigatran (150 mg), and rivaroxaban, respectively (negative numbers indicate cost reduction). For NVAF patients with high stroke risk (CHADS2 ≥ 3) differences in clinical event medical costs vs. warfarin were -$697, +$2, and -$100 for apixaban, dabigatran (150 mg), and rivaroxaban, respectively.

CONCLUSIONS: Medical cost differences associated with OACs vs. warfarin vary according to stroke risk. Of the three OACs, apixaban demonstrated consistent medical cost reductions vs. warfarin for NVAF patients with moderate and high stroke risks.