Subjective and Objective CPAP Compliance in Patients with Obstructive Sleep Apnea Syndrome

Abstract

Introduction: The aim of this study was to investigate the objective and subjective CPAP compliance in patients with obstructive sleep apnea syndrome (OSAS). Also, we evaluated the factors and benefits that were associated with good compliance to CPAP use. Methods: Patients with OSAS who underwent polysomnography for CPAP titration between November 2006 and September 2009 were included in this study. Body mass index (BMI), Epworth sleepiness scale (ESS), Pittsburgh sleep quality index (PSQI) and Beck depression inventory (BDI) were obtained before and during CPAP use. Subjective and objective compliance were defined as CPAP use of 5d/wk with 4hr/d, and 70% of recording time with 4hr/d. Results: A total of 148 patients with a mean age (± SD) of 53.8 (± 12.2) years were examined. The subjective and objective compliance was 32.4% and 20.9%. Among subjectively compliant patients, 73.7% of them were objectively compliant. In 75 patients who discontinued CPAP treatment, 71% of them had stopped CPAP use within a month. Subjectively compliant patients had higher CPAP pressure, lower PSQI score, lower minimum O2 saturation and higher % time of O2 saturation lower than 90% than non-compliant patients. Objectively compliant patients had higher CPAP pressure, lower PSQI and BDI score, higher BMI and lower minimum O2 saturation than non-compliant patients. ESS and PSQI were significantly improved both in objectively compliant and partial-compliant patients. The improvement was more prominent in compliant than partial-compliant group, although statistically insignificant. Conclusion: Lower insomnia score and more severe degree of OSA were related with better CPAP compliance. As effects of CPAP use were evident with higher objective compliance and some patients overestimated their CPAP use, determination of objective compliance is essential in evaluating CPAP compliance and it effects.