Data from: Determinants for adherence to continuous positive airway pressure therapy in obstructive sleep apnea

Background: Continuous positive airway pressure (CPAP) therapy is an
efficacious treatment for patients diagnosed with obstructive sleep apnea
(OSA). However, there are only few data on long-term adherence. The aim of
this study is to quantify the extent of non-adherence and describe the
clinical characteristics. Methods: A retrospective study including 695
patients with newly diagnosed OSA and prescribed CPAP therapy within an
inclusion period of 14 months. All patients were offered free of charge
individually adjusted CPAP therapy. Data on comorbidity, medication, BMI
and Epworth Sleepiness Score (ESS) were obtained by questionnaires and
consultation with an otorhinolaryngeal specialist. Results: The median
follow-up time after initiating CPAP therapy was 3.0 (range 2.4–3.6)
years. An adherence rate of 89% was found for severe OSA, 71% for moderate
OSA and 55% for mild OSA. 18% initiated humidification. Patients adherent
to CPAP had a significantly higher Body Mass Index (BMI), Apnea Hypopnea
Index (AHI), Oxygen Desaturation Index (ODI) and ESS compared to
non-adherent patients. Furthermore, adherence was associated with a higher
frequency of observed interrupted breathing, a less frequent use of
hypnotic drugs, fewer smokers, and they were more often offered
humidification. Age, gender and comorbidity were not significantly
associated with adherence. In a Cox model only AHI (Hazard Ratio (HR)
0.963, p < 0.001), ESS (HR 0.939, p = 0.001) and smoking (HR 1.576,
p = 0.022) were independently associated with CPAP non-adherence.
Conclusions: The severity of OSA, subjective daytime sleepiness and
smoking status are independently related to adherence to CPAP therapy.