Novel Oral Anticoagulants Versus Warfarin Therapy at Various Levels of Anticoagulation Control in Atrial Fibrillation-A Cost-Effectiveness Analysis

BACKGROUND: The decision as to whether to use more expensive novel oral anticoagulants (NOACs) or invest resources for quality improvement of warfarin therapy requires input from both clinical and economic analyses. Cost-effectiveness of NOACs compared to warfarin therapy at various levels of patient-time in therapeutic range (TTR) in patients with atrial fibrillation was examined, from the healthcare provider's perspective. A Markov model was used to compare life-long economic and treatment outcomes of warfarin and NOACs in a hypothetical cohort of 65-year-old atrial fibrillation patients with CHADS(2) scores of 2 or above. Model inputs were derived from clinical trials published in the literature. The outcome measure was incremental cost per quality-adjusted life-year (QALY) gained (ICER). Using United States Dollar (USD) 50,000 as the threshold of willingness-to-pay per QALY, NOACs therapy was cost-effective when TTR of warfarin therapy was 60 % or below, or monthly cost of warfarin management increased by two-fold or more to achieve 70 % TTR. Warfarin therapy was cost-effective when TTR of warfarin was 70 % with up to a 1.5-fold increment in monthly cost of care, or when TTR reached 75 % with monthly cost of warfarin care increased up to three-fold. At TTR 60 %, 70 % and 75 %, NOACs was cost-effective when monthly drug cost was < USD 200, < USD 122-185 and < USD 85-145, respectively. 10,000 Monte Carlo simulations showed NOACs to be cost-effective 83.6 %, 50.7 % and 32.7 % of the time at TTR of 60 %, 70 % and 75 %, respectively. The acceptance of NOACs as cost-effective was highly dependent upon drug cost, anticoagulation control for warfarin, and anticoagulation service cost.