Recently, secondary stroke prevention in those with atrial fibrillation has become more exciting with the recent addition of new anticoagulants such as dabigatran, apixaban, and rivaroxaban to the previous mainstay, warfarin. While the focus has been on the differences in pharmacological properties between these medications, economic differences should also be considered.
Harrington et al. from the University of Arizona sought to estimate the cost-effectiveness of stroke prevention in patients with nonvalvular atrial fibrillation, comparing those receiving apixaban 5mg, dabigatran 150mg, and rivaroxaban 20mg with warfarin. Using a Markov decision-analysis model, the group sought to account for not only complications and associated costs of the medication using probability of adverse events from recent studies such as ARISTOTLE, RE-LY, and ROCKET-AF, but life expectancy, willingness-to-pay analysis, measured in quality-adjusted-life-years (QALY). The group found that the QALY estimate for apixaban was the highest, whereas the lowest was for that of warfarin.
This is the first study to compare several of the novel anticoagulants against each other in relation to warfarin. Although this type of study has inherent limitations based on assumptions and variations in data sources, this study is valuable at a time when clinicians are still learning to incorporate these medications into their practice. Until we have better data on such areas as side effects and treatment compliance, this study suggests that the new oral anticoagulants have added economic benefit compared to the time-tested warfarin, providing further incentive to prescribe them.