Impact of Pressure Variability and Comorbidities on PAP Therapy Compliance and Adherence in Obstructive Sleep Apnea

Obstructive sleep apnea syndrome (OSAS) is a common disorder with established cardiovascular and metabolic risks. Positive airway pressure (PAP) therapy remains the standard of care; however, its long-term effectiveness is often limited by poor compliance and adherence. This study sought to explore clinical and device-related factors influencing PAP use, with emphasis on pressure variability in Auto-PAP users and comorbidities such as COPD. We performed a retrospective analysis of 359 patients with OSAS who were treated with CPAP, Auto-PAP, or BiPAP devices at the Marius Nasta Institute of Pneumology between January 2022 and July 2024. Compliance was measured as the proportion of days the device was used, whereas adherence was estimated through average nightly hours of use. Patient data were stratified by demographic, clinical, and device-related characteristics. Statistical testing included Chi-square, Wilcoxon rank-sum, and correlation analyses. Demographics did not significantly differ between compliant and non-compliant groups. Notably, Auto-PAP users with greater pressure variability (>10 cm H₂O) had significantly lower compliance (p = 0.001). Nasal mask preference was also associated with poorer compliance (p = 0.030). Multivariate models further revealed that atrial fibrillation reduced the likelihood of good adherence (OR = 0.319, 95% CI 0.137-0.746). These results highlight the importance of monitoring pressure variability, device type, and comorbidities to personalize PAP therapy and improve long-term outcomes.