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 supine-avoidance 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 κ 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.