Factors Affecting Patients' Adherence to Continuous Positive Airway Pressure Therapy for Obstructive Sleep Apnea Disorder: A Multi-Method Approach

Background: Continuous positive airway pressure (CPAP) is the gold standard therapy for treating obstructive sleep apnea (OSA) disorder. However, patients' adherence to its regular use is poor. The present study aimed to determine the adherence rate to CPAP therapy by identifying factors affecting its regular use and its associated problems and discomforts among a sample population in Mashhad (Iran).

Methods: The study was conducted from October 2017 to March 2018 in Mashhad (Iran) using both quantitative and qualitative methods. The quantitative study was carried out using a retrospective cross-sectional data collection from five sleep clinics and one CPAP sales office. The patients were classified into an adherent and a non-adherent group to determine the factors affecting CPAP adherence. Quantitative data were analyzed using SPSS software (version 22.0). Additionally, a prospective qualitative study was performed through a series of telephone interviews using the content analysis method. Qualitative data were analyzed using MAXQDA 10 software.

Results: In the quantitative study, the medical records of 159 patients were used, out of which 79 (49.6%) were non-adherent to CPAP therapy. The mean age of all patients was 56.9±9.8 years. The mean body mass index, apnea-hypopnea index, and Epworth sleepiness scale (ESS) scores were 30.9±6.6 kg/m, 37.2±28.1 events/hour, and 10.4±5.5, respectively. At baseline, the adherent group had a significantly higher age (P=0.006), higher oxygen desaturation index (P=0.006), and lower ESS (P=0.023) compared to the non-adherent group. In the qualitative study, a total of 29 telephone interviews were held with patients from the non-adherent group (8 women and 21 men). Analysis of the interviews resulted in three main categories (level of knowledge, discomfort, and costs) and nine sub-categories.

Conclusion: A high percentage of OSA patients had poor adherence to CPAP therapy. Device-related issues could be adequately resolved by providing complementary information during follow-up visits. Moreover, efforts to reduce costs through comprehensive insurance coverage or with government subsidy would improve patients' adherence to CPAP therapy.