Accurate Position Monitoring and Improved Supine-Dependent Obstructive Sleep Apnea with a New Position Recording and Supine Avoidance Device

Study Objectives: Approximately 30% of obstructive sleep apnea (OSA) patients have supine-predominant OSA, and simply avoiding supine sleep should normalise respiratory disturbance event rates. However, traditional supineavoidance therapies are inherently uncomfortable, and treatment adherence is poor and difficult to monitor objectively. This study evaluated the efficacy of a novel, potentially more acceptable position monitor and supine-avoidance device for managing supine-predominant OSA and snoring. Design and Setting: In-laboratory evaluation of position recording accuracy versus video recordings (validation study), and randomized controlled crossover trial of active versus inactive supine-avoidance therapy in the home setting (efficacy study). Patients: 17 patients undergoing in-laboratory sleep studies (validation) and 15 patients with supine-predominant OSA (efficacy). Interventions: Efficacy study: 1 week of inactive and 1 week of active treatment in randomized order, separated by 1 week. Measurements and Results: Agreement between 30-sec epoch-based posture classifications from device versus video records was high (median K 0.95, interquartile range: 0.88-1.00), and there was good supine time agreement (bias 0.3%, 95%CI: -4.0% to 4.6%). In the efficacy study, apnea-hypopnea index (AHI) and snoring frequency were measured in-home using a nasal pressure and microphone based system during inactive and active treatment weeks. The position monitoring and supine alarm device markedly inhibited supine time (mean ± SEM 19.3% ± 4.3% to 0.4% ± 0.3%, p < 0.001) and reduced AHI (25.0 ± 1.7 to 13.7 ± 1.1 events/h, p = 0.030) but not snoring frequency. Conclusions: This new position monitoring and supine alarm device records sleep position accurately and improves OSA but not snoring in patients with supine-predominant OSA.