Is the importance of positional therapy for treatment of obstructive sleep apnea overestimated?

<bold>Introduction:</bold> Obstructive sleep apnea (OSA) is a common condition leading to interrupted sleep, thereby causing daytime somnolence and promoting cardiovascular morbidity. Positional therapy (PT) is frequently recommended as first-line treatment in OSA. <bold>Aim of the study:</bold> To elucidate the sensitivity of Polysomnography (PSG) to diagnose position dependent OSA and to estimate the portion of OSA patients who could benefit from PT. <bold>Methods:</bold> We analysed 388 consecutive PSG’s from 2023 for suspected OSA in our tertiary hospital. <bold>Results:</bold> The cohort included 67% males, 54±14.7 years of age, BMI of 30±6 kg/m2, Epworth Sleepiness Scale Score (ESS) 8.3±4.4 (normal <10). In 13% of patients strict supine position (n=50) or never-supine position (50) were detected respectively. 39.4% had no position-dependency (n=153) and 34.5% had a clear position dependency (n=134). In position dependent (PD)-OSA 62% were male, age 52.7 yrs, ESS 8.6, AHI 14/h and BMI 28.3kg/m2. In the position independent (PID)-OSA 67% male, age 54.1 yrs, ESS 8.0, AHI 32.8/h and BMI 31kg/m2. In never-supine position 70% male, age 58.1 yrs, ESS 8.3, AHI 22.2/h, BMI 29.9kg/m2. In strict-supine position 61% male, age 54.2 yrs, ESS 8.4, AHI 34.1/h, BMI 31.8kg/m2. In PD-OSA the AHI was significantly lower (13.9/h) than in PID-OSA (32.8/h), p<0.001. Surprisingly the ESS was not significantly higher in PID-OSA with 8.6 than in PD-OSA with 8, p=0.45. Only in 6/388 PD-OSA patients (1.5%) and increased ESS we would have seen an indication for PT. <bold>Conclusion:</bold> ESS is not a reliable predictor for severity of OSA or position dependency. PSG fails to predict PT in 26% of patients. Only 1.5% of all patients qualify for PT.