Cost-effectiveness of rivaroxaban for stroke prevention in atrial fibrillation in the Portuguese setting. 
To project the long-term cost-effectiveness of treating non-valvular atrial fibrillation (AF) patients for stroke prevention with rivaroxaban compared to warfarin in Portugal.  A Markov model was used that included health and treatment states describing the management and consequences of AF and its treatment.  The model's time horizon was set at a patient's lifetime and each cycle at three months.  The analysis was conducted from a societal perspective and a 5% discount rate was applied to both costs and outcomes.  Treatment effect data were obtained from the pivotal phase III ROCKET AF trial.  The model was also populated with utility values obtained from the literature and with cost data derived from official Portuguese sources.  The outcomes of the model included life-years, quality-adjusted life-years (QALYs), incremental costs, and associated incremental cost-effectiveness ratios (ICERs).  Extensive sensitivity analyses were undertaken to further assess the findings of the model.  As there is evidence indicating underuse and underprescription of warfarin in Portugal, an additional analysis was performed using a mixed comparator composed of no treatment, aspirin, and warfarin, which better reflects real-world prescribing in Portugal.  This cost-effectiveness analysis produced an ICER of €3895/QALY for the base-case analysis (vs. warfarin) and of €6697/QALY for the real-world prescribing analysis (vs. mixed comparator).  The findings were robust when tested in sensitivity analyses.  The results showed that rivaroxaban may be a cost-effective alternative compared with warfarin or real-world prescribing in Portugal.