LAUSR

Study objectives: To evaluate, in a large multicenter clinical cohort of obstructive sleep apnea (OSA) patients, the prevalence and factors independently associated with predominant positional OSA (POSA, [IAHD/IAHND≥2]) and exclusive POSA (e-POSA, [OSA + IAHNDl5]). The secondary objective was to assess the outcome of CPAP treatment for these patients. Methods: This retrospective study included 6,437 typical mild‐to‐severe OSA patients. Patients with POSA and e-POSA were compared to those without POSA (NPOSA) for clinical and polygraphic characteristics. In a subgroup of patients (n=3,000) included in a CPAP therapy follow-up analysis, we assessed whether POSA and e-POSA phenotypes were associated with treatment outcomes at 6 months. Results: POSA and e-POSA had a prevalence of 53.5% and 20.1% respectively and were independently associated with time in supine position (longer), gender (male), age (younger), AHI (lower) and BMI (lower). After adjusting for confounding factors, patients with POSA or e-POSA had a significantly lower probability of adhering to CPAP therapy (≥4h/day) at 6 months. In addition, compared to NPOSA patients, these patients had a higher risk of discontinuing CPAP treatment. Conclusions: The prevalence and independent predictors of POSA and e-POSA were determined in this large clinical population. POSA and e-POSA patients have lower CPAP adherence and this choice of treatment may not be optimal. Thus, an alternative therapy should be considered for these patients.