Cost-Utility Analysis of Continuous Positive Airway Pressure Therapy Compared With Usual Care for Obstructive Sleep Apnea in the Public Health System in Brazil

Abstract

ObjectivesThis study aimed to conduct a cost-utility analysis of continuous positive airway pressure (CPAP) therapy compared with usual care as treatment of moderate to severe cases of obstructive sleep apnea (OSA) in Brazil, where decentralized policies of CPAP provision are in place. MethodsMarkov cohort model comparing CPAP therapy with usual care, that is, no specific treatment for OSA, for moderate to severe cases was used. The payer perspective from the Unified Health System, Brazil, was adopted. Effectiveness parameters and costs related to health states were informed by literature review. Resource use related to CPAP therapy was defined by specialists and costs informed by recent purchase and leasing contracts. Incremental cost-effectiveness ratios were generated for purchase and leasing contracts to reflect current practices. A conservative willingness-to-pay threshold was set at 1 gross domestic product per capita per quality-adjusted life-year (QALY) (Brazilian reais [BRL] 40 712/QALY). Uncertainties were explored in deterministic and probabilistic sensitivity analyses. ResultsIncremental cost-effectiveness ratio for the purchase modality was 8303 BRL/QALY and for leasing 45 192 BRL/QALY. Considering the adopted willingness-to-pay threshold, provision of CPAP by the purchase modality was considered cost-effective but not the leasing modality. The parameter related to the greatest uncertainty was the reduction in the risk of having a stroke attributable to CPAP. Probabilistic analysis confirmed the robustness of results. ConclusionsCPAP therapy is a cost-effective alternative compared with usual care for moderate to severe OSA for the purchase modality. These results should help underpinning the decision making related to a uniform policy of CPAP provision across the country.