Long-term adherence to continuous positive airway pressure therapy in non-sleepy sleep apnea patients

Abstract

Objective: The effectiveness of continuous positive airway pressure (CPAP) therapy greatly depends on consistent use. However, data regarding adherence in non-sleepy obstructive sleep apnea (OSA) patients are scarce. The aim of this study was to assess long-term adherence and predictors of CPAP compliance in a large sample of non-sleepy OSA patients.

Methods: We conducted a prospective, multicenter study comprising 357 non-sleepy patients (Epworth Sleepiness Scale score <11) with moderate-to-severe OSA (apnea-hypopnea index [AHI] of ≥20) who began CPAP therapy between May 2004 and May 2006; follow-up ended in May 2009. Non-compliance was scored as CPAP dropout or average cumulative CPAP use of <4 hours per night. Multivariate Cox regression analysis was performed to identify independent predictors of poor CPAP adherence.

Results: Patients were followed up for a median of four years (interquartile range [IQR] = 3.0-4.4). At the end of the study period, 230 patients (64.4%) fulfilled the criteria for good CPAP compliance, whereas 127 patients (35.6%) were considered non-compliant. The median CPAP use was five hours per night (interquartile range = 2.18-6.25). Multivariate analysis showed that interactions between the AHI and the percentage of nighttime spent with an O2 saturation of <90% (TC90) (p = 0.010) and between the AHI and hypertension at baseline (p = 0.029) predicted long-term compliance with CPAP.

Conclusion: This study demonstrates that CPAP treatment is feasible in non-sleepy, moderate-to-severe OSA patients. Good CPAP adherence was predicted by greater OSA severity as measured by both the AHI and TC90 and by the presence of hypertension at baseline in patients with higher AHI levels.

Keywords: Adherence; Continuous positive airway pressure; Excessive daytime sleepiness; Obstructive sleep apnea.