ObjectiveTo assess the cost-effectiveness of apixaban versus acetylsalicylic acid (ASA) in stroke prevention in patients with non-valvular atrial fibrillation (NVAF) with contraindications of vitamin K antagonists in Spain. MethodsA Markov model was adapted, simulating the patient's lifetime. The safety and efficacy of the drugs were obtained from AVERROES clinical trial. The analysis was done from the Spanish National Health System (NHS) and societal perspective. The cost of drugs was calculated according to the recommended doses. The cost of NVAF complications and disease management was obtained from Spanish sources. ResultsIn a cohort of 1,000 patients with NVAF, during their lifetime numerous complications could be avoided with apixaban versus ASA (48 ischemic strokes, 10 systemic embolism and 53 related deaths). In each patient treated with apixaban more life-years (0.303 LYG) and more quality-adjusted life-years (0.277 QALYs) could be gained. Apixaban would generate more costs per patient for the NHS (€1,742 per patient) but savings would result from the social perspective (€2,887 saved per patient). The cost per LYG and QALY gained would be of €5,749 and €6,289 for the NHS. Apixaban would be dominant (more effective with less costs than ASA) from the societal perspective. The results were stable in both deterministic and probabilistic sensitivity analyses. ConclusionsAccording to this model, when costs and estimated lifetime outcomes achieved with apixaban are compared with those of ASA, apixaban was assessed to be a cost-effective treatment for the prevention of stroke in patients with NVAF in Spain.