Custo-utilidade da rivaroxabana comparada a varfarina na prevenção do acidente vascular cerebral na fibrilação atrial não valvar no Sistema Único de Saúde

Abstract

Atrial fibrillation is the most common sustained cardiac arrhythmia, affecting mainly the elderly and increases the risk of stroke. It is currently a public health problem because of its high morbidity and mortality and increasing costs. Warfarin is an anticoagulant that was effective in preventing this type of stroke, but has limitations that contribute to its low adhesion and underutilization. The emergence of new anticoagulants such as rivaroxaban, suggest that this drug may be as effective as warfarin, but with lower rates of major bleeding complications, mainly brain. Also, with this drug, there is no need for monitoring tests, but is more expensive. The aim of this study was to evaluate the cost-utility of rivaroxabana compared to warfarin in this arrhythmia, or compare the cost of a health intervention with effectiveness measured as a gain in years of life adjusted for quality. Initially, a systematic review of economic studies was performed that suggest that rivaroxaban can be a cost-effective option compared to warfarin, especially in developed countries. There was only one study in a developing country which showed divergent results. Later, it was developed an economic model of Markov was developed with the Unified Health System perspective, which allowed simulation of the evolution of a cohort of elderly patients with Atrial fibrillation in quarterly cycles throughout life. The results showed that the incremental costs of rivaroxaban was superior to warfarin (R$ 7.135,48), with a slight increase of utility, resulting in incremental cost-utility ratio of R$ 206.816,45/years of life adjusted for quality. This value is above the threshold proposed by the Wolrd Health Organization, may not be a cost-effective option. Despite the limitations, this study brought together the available evidence and showed the need to adjust the clinical protocols and guidelines for clinical practice that can reconcile the principles of comprehensive care to the sustainability of the health system.