A COST-UTILITY ANALYSIS COMPARING CONTINUOUS POSITIVE AIRWAY PRESSURE, ORAL APPLIANCE, AND SURGERY WHEN TREATING MODERATE OBSTRACTIVE SLEEP APNEA IN MIDDLE-AGED CANADIAN MALES

Purpose: Continuous positive airway pressure (CPAP) is the recommended first line treatment in obstructive sleep apnea (OSA); however, other treatment options could be considered. The objective of this study was to compare the health and economic outcomes related to CPAP, oral appliances, and surgery such as uvulopalatopharyngoplasty (UPPP) and maxillomandibular advancement (MMA) when managing OSA.

Method: A cost-utility analysis was conducted. A decision tree and Markov cohort model simulated the outcomes and costs of treatment options based on their effects on motor vehicle and workplace injuries, cardiovascular events and all-cause mortality rates. The base case was a 45 year old Canadian male patient with moderate OSA, who operated a motor vehicle, was employed, and had no significant co-morbidities aside from OSA. Costs out probabilities, utilities and costs were obtained from systematic searches of the medical literature. Baseline CPAP compliance (defined as using CPAP machine more than 4 hours per night, and more than 5 nights per week) was estimated at 50%. Outcomes measured were quality adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). Patients were followed for their expected lifetime and outcomes were discounted at 3% per year. We adopted a Canadian insurer perspective.

Result: The cost-effectiveness of various strategies to treat OSA is critically dependent upon compliance with CPAP, effectiveness of oral appliances treatment and cost of UPPP surgery. Only at compliance rates ≥90% CPAP as the dominant therapy is the most effective (13.3 QALYs) and least costly ($14,190) option. However, at CPAP compliance rates below 67%, UPPP becomes the most cost-effective first strategy (ICER = $1,473/QALY gained in comparison to CPAP). Oral appliances are only cost-effective when both CPAP compliance is poor (< 50%), and UPPP surgical success rate is poor (<64%), and oral appliance success rate is more than 61%, with and ICER = $1,500/QALY gained in comparison to surgery.

Conclusion: Cost-effectiveness of strategies to treat moderate OSA in middle-age Canadian males without significant co-morbidities is critically dependent upon CPAP compliance, as surgery becomes the preferred strategy when compliance with CPAP (using CPAP machine more than 4 hours per night, and more than 5 nights per week) is less than> 90%.