Limiares de custo-efetividade e a precificação de medicamentos: aripiprazol para o tratamento da esquizofrenia no Brasil

Abstract

INTRODUCTION: For a new technology to be recommended based on cost-effectiveness analysis, the incremental cost-effectiveness ratio must be compared to a cost-effectiveness threshold value that should represent the highest acceptable value for an extra unit of benefit. When an agency determines the adoption of a specific cost-effectiveness threshold, a strategic behavior is expected from technology producers that determine their prices according to that threshold. OBJECTIVE: This study aims to evaluate the cost-effectiveness of aripiprazole for the treatment of schizophrenia compared to the technologies available in the public health system in Brazil and to determine the maximum possible price for its incorporation under a substitutive technology approach. METHODS: Initially, a review was performed on the methods for determining cost-effectiveness thresholds and examples of values adopted around the world. Then, a cost-effectiveness evaluation was performed comparing aripiprazole to the listed technologies in the Brazilian public health system for the treatment of schizophrenia. A value proposition for the threshold was explained and applied to the pricing of aripiprazole. RESULTS: Cost-effectiveness thresholds are usually calculated through three different approaches: the willingness to pay method; the precedent method; and the opportunity costs method. Each of these methods provides a different value for the threshold. In health systems with fixed budgets, it is suggested that the best approach is that of opportunity costs. In the costeffectiveness analysis, olanzapine was considered cost-effective in any definition already proposed for LCE. Aripiprazole was completely dominated by risperidone and extendedly dominated by chlorpromazine and olanzapine. Aripiprazole, even with the drug price set at zero, provided higher cost-effectiveness ratios than the other non-dominated drugs [$ 8,303 vs. $ 7,985 (haloperidol), $ 7,320 (chlorpromazine), $ 7,380 (risperidone) and $ 7,594 (olanzapine) BRL/AVAQ]. CONCLUSION: Aripiprazole was absolutely dominated and there is no viable price that makes it recommended for incorporation into the Brazilian public health system.