Health Outcomes of CPAP versus Oral Appliance Treatment for Obstructive Sleep Apnea: A Randomised Controlled Trial

Rationale: Continuous Positive Airway Pressure (CPAP) and Mandibular Advancement Device (MAD) therapy are commonly used to treat Obstructive Sleep Apnea (OSA). Differences in efficacy and compliance of these treatments are likely to influence improvements in health outcomes. Objectives and Methods: To compare health effects after 1 month of optimal CPAP and MAD therapy in OSA using a randomised crossover design. Measurements and main results: Cardiovascular (24-hour blood pressure, arterial stiffness), neuro-behavioural (subjective sleepiness, driving simulator performance) and Quality of Life (FOSQ, SF-36) were compared between treatments. Our primary outcome was 24-hour mean arterial pressure (24MAP). 126 patients with moderatesevere OSA (AHI = 25.6 (SD 12.3)) were randomly assigned to a treatment order and 108 completed the trial with both devices. CPAP was more efficacious than MAD in reducing AHI (CPAP AHI=4.5±6.6/hr, MAD AHI=11.1±12.1/hr, p<0.01) but reported compliance was higher on MAD (MAD: 6.50±1.3 hrs/night versus CPAP: 5.20±2.0 hrs/night, p<0.00001). 24MAP was not inferior on treatment with MAD compared to CPAP (CPAP-MAD difference, 0.2mmHg [95%CI -0.7 to 1.1], however overall, neither treatment improved BP. In contrast, sleepiness, driving simulator performance and disease-specific QOL improved on both treatments by similar amounts although MAD was superior to CPAP for improving four general QOL domains. Conclusions: Important health outcomes were similar after 1 month of optimal MAD and CPAP treatment in patients with moderate-severe OSA. The results may be Page 5 of 51