Cost–effectiveness of apixaban and warfarin in the prevention of thromboembolic complications among atrial fibrillation patients

BACKGROUND To reduce the risk of thromboembolic complications, clinical guidelines recommend anticoagulation treatment for almost all atrial fibrillation (AF) patients. Although warfarin has long been the primary treatment alternative, now newer alternatives such as apixaban have proven effective in prevention of the thromboembolic complications of non-valvular AF. The aim of this study is to assess the cost-effectiveness of apixaban when compared with warfarin in the prevention of AF-associated thromboembolic complications in Finland. METHODS The assessment was performed with a lifetime Markov-model with the following health states: non-valvular AF, ischemic stroke, hemorrhagic stroke, other intracranial bleed, other major bleed, clinically relevant non-major bleed, myocardial infarction, and systemic embolism. The treatment efficacies were obtained from the ARISTOTLE trial. Representative Finnish input data were used for the model states, including background mortality, resource use, costs (in 2014 values), and EQ-5D-3L-based quality of life. The results (with 3 % annual discounting) are presented as incremental cost-effectiveness ratios [ICER, cost per quality-adjusted life year (QALY) gained], the expected value of perfect information (EVPI), and the probability of apixaban being cost-effective at various willingness-to-pay levels. RESULTS Apixaban increased life-expectancy by 0.17 years and quality-adjusted life-expectancy by 0.14 QALYs when compared with warfarin. Additional QALY was gained with apixaban at a cost of 1824 euros based on the deterministic analysis. The maximum EVPI was 649 euros/patient at 1282 euros per QALY gained in the probabilistic analysis. The probability of apixaban being cost-effective reached 80 % when the willingness-to-pay per QALY gained was 14,857 euros. In deterministic sensitivity analyses, ICERs varied from dominance of apixaban to additional QALY being gained at a cost of 12,312 euros. CONCLUSIONS The ICERs obtained were well below the WHO-CHOICE threshold values for cost-effective interventions, suggesting that apixaban is a very cost-effective treatment alternative for warfarin in Finnish patients with AF.