Twenty years compliance with continuous positive air pressure treatment in patients with severe obstructive sleep apnea

Although continuous positive air pressure (CPAP) has been used to treat obstructive sleep apnea (OSA) for more than three decades, few studies have reported > 5 years adherence to the treatment. The aim of our study was to assess compliance with CPAP treatment over a long term period ranging from 5 to 20 years. From a database of 650 patients with severe OSA (AHI>30) who started CPAP treatment between 1998 and 2006 we retrospectively collected preliminary data for 105 patients. Demographic and clinical data (e.g. polysomnographic, Epworth Sleepiness Scale) and co-morbidities were available from the database. All patients underwent a telephonic interview to assess the actual use of CPAP, hours of nocturnal treatment, causes of cessation and occurrence of new morbidities during the treatment period. At the beginning of the therapy patients (72% males) had a mean age of 54.9±9.6 yrs, AHI 52.5 ±19.6, BMI 32.2± 6.3 and an Epworth Sleepiness Scale score of 10.9 ±4.6. We found that compliance with CPAP slightly decreased, although remaining quite high, over a long period of time being 94% during the first year, 89% at 5 yrs, 88.7% at 10 yrs, 85.5 % at 15 yrs and 84.3% at 20 yrs. The mean duration of the treatment before suspension was 7.6±4 yrs. The mean rate of nocturnal use did not significantly change over the time and was 7.2 ± 1.9 hours/day at 20 yrs. The long term adherence to CPAP therapy was significantly associated with younger age of the patients, female sex and more severe sleepiness, but not with the severity of OSA. These preliminary data indicate that compliance with CPAP treatment in patients with severe OSA, although a slight decrease through the time, remains high at twenty years follow-up.