Comparative Effectiveness of Supine-Avoidance versus Continuous Positive Airway Pressure for Treating Supine-isolated Sleep Apnea

Around 20-35% of obstructive sleep apnoea (OSA) patients show supine-isolated OSA, where supine sleep avoidance could be an effective therapy. However, traditional supine discomfort-based methods show poor tolerance and compliance to treatment, so cannot be recommended. Supine-alarm devices show promise, but evidence to support favourable adherence to treatment and effectiveness at reducing excessive daytime sleepiness compared to continuous positive airway pressure (CPAP) remains limited.To establish if alarm-based supine-avoidance treatment in supine-isolated OSA patients is non-inferior to CPAP in reducing daytime sleepiness.Following baseline questionnaires and in-home supine-time and polysomnography assessments, patients with supine-isolated OSA and Epworth sleepiness scale (ESS) score ≥8 were randomised to ≥6 weeks of supine-avoidance or CPAP treatment, followed by cross-over to the remaining treatment with repeat assessments. Non-inferiority was assessed from change in ESS with supine-avoidance compared to CPAP using a pre-specified non-inferiority margin of 1.5. Average nightly treatment use over all nights, and treatment efficacy and effectiveness at reducing respiratory disturbances were also compared between treatments.The reduction in sleepiness score with supine-avoidance (mean [95%CI] -1.9 [-2.8 to -1.0]) was non-inferior to CPAP (-2.4 [-3.3 to -1.4], supine-avoidance-CPAP difference -0.4 [-1.3 to 0.6]) and the lower confidence limit did not cross the non-inferiority margin of 1.5, p=0.021. Average treatment usage was higher with supine-avoidance compared to CPAP (mean ± SD 5.7 ± 2.4 versus 3.9 ± 2.7 h/night, p<0.001).In patients with supine-isolated OSA, vibro-tactile supine alarm device therapy is non-inferior to CPAP for reducing sleepiness and shows superior treatment adherence.