Medical cost reductions associated with the usage of novel oral anticoagulants vs warfarin among atrial fibrillation patients, based on the RE-LY, ROCKET-AF, and ARISTOTLE trials

Abstract

OBJECTIVE: The randomized clinical trials, RE-LY, ROCKET-AF, and ARISTOTLE, demonstrate that the novel oral anticoagulants (NOACs) are effective options for stroke prevention among non-valvular atrial fibrillation (AF) patients. This study aimed to evaluate the medical cost reductions associated with the use of individual NOACs instead of warfarin from the US payer perspective. METHODS: Rates for efficacy and safety clinical events for warfarin were estimated as the weighted averages from the RE-LY, ROCKET-AF and ARISTOTLE trials, and event rates for NOACs were determined by applying trial hazard ratios or relative risk ratios to such weighted averages. Incremental medical costs to a US health payer of an AF patient experiencing a clinical event during 1 year following the event were obtained from published literature and inflation adjusted to 2010 cost levels. Medical costs, excluding drug costs, were evaluated and compared for each NOAC vs warfarin. Sensitivity analyses were conducted to determine the influence of variations in clinical event rates and incremental costs on the medical cost reduction. RESULTS: In a patient year, the medical cost reduction associated with NOAC usage instead of warfarin was estimated to be -$179, -$89, and -$485 for dabigatran, rivaroxaban, and apixaban, respectively. When clinical event rates and costs were allowed to vary simultaneously, through a Monte Carlo simulation, the 95% confidence interval of annual medical costs differences ranged between -$424 and +$71 for dabigatran, -$301 and +$135 for rivaroxaban, and -$741 and -$252 for apixaban, with a negative number indicating a cost reduction. Of the 10,000 Monte-Carlo iterations 92.6%, 79.8%, and 100.0% were associated with a medical cost reduction >$0 for dabigatran, rivaroxaban, and apixaban, respectively. CONCLUSIONS: Usage of the NOACs, dabigatran, rivaroxaban, and apixaban may be associated with lower medical (excluding drug costs) costs relative to warfarin, with apixaban having the most substantial medical cost reduction.