Abstract 172: Cost-Effectiveness of Dabigatran Compared with Warfarin for Secondary Stroke Prevention in Patients with Atrial Fibrillation and Prior Stroke or Transient Ischemic Attack

Abstract

Background: The cost-effectiveness of dabigatran for secondary stroke prevention in patients who present with atrial fibrillation (AF) and stroke or transient ischemic attack (TIA) has not been directly assessed. Methods: A Markov decision model was constructed (Figure 1) using data from a substudy of the Randomized Evaluation of Long-Term Therapy (RE-LY) trial, other trials of warfarin therapy for AF, and the published cost of dabigatran. We compared two treatment strategies: adjusted-dose warfarin therapy with an international normalized ratio (INR) target of 2 to 3, versus dabigatran 150 mg twice daily. The target population was a cohort of patients aged 70 years and older with non-valvular AF, prior stroke or TIA, and no contraindication to anticoagulation. The model outputs were costs in 2010 U.S. dollars and quality-adjusted life-years (QALYs). Results: In the base case, quality-adjusted life expectancy was 4.36 QALYs with dabigatran compared with 4.04 QALYs with warfarin. Dabigatran provided 0.34 additional QALYs at a cost of $9,500, yielding an incremental cost-effectiveness ratio of $28,000. In sensitivity analyses (Figure 2), the cost-effectiveness of dabigatran was influenced by patients’ age, the cost of dabigatran, the relative risk of stroke using dabigatran compared with warfarin, and the quality of INR control achieved with warfarin therapy. Conclusions: Dabigatran appears to be cost-effective relative to warfarin for stroke prevention in patients with AF and prior stroke or TIA. Our analysis is limited by its reliance on data from a substudy of a single randomized trial, and our results may not apply in settings with atypically good INR control using warfarin.