This study aims to determine the average compliance of a patient under CPAP therapy for obstructive sleep apnea as well as the various factors that influence it.

Obstructive Sleep Apnea (OSA) is a frequent disease that affects 4% of the male population and 2% of the female population, with well known repercussions on the quality of life (daytime drowsiness, concentration issues, increased motor vehicle accidents, etc) and cardiovascular risk (increased risk of strokes, hypertension, diabetes, CAD, etc.). It is caused by an intermittent relaxation of the throat muscles during sleep, thus blocking the airways and leading to snoring and apnea.

Treatment can involve diets and sports, sleep hygiene techniques, mandibular advancement devices. But the CPAP (continuous positive airway pressure) device remains the first line therapy for OSA. It is very effective at reducing apnea-hypopnea (AHI) and oxygen desaturation indexes (ODI), but poor compliance is often noticed, with only 46% of patients still using the device at 6 months.

Despite numerous studies on the subject, very few have included a large number of patients(>150) or long follow up time (>1 year), or reached conclusive evidence concerning the factors that influence CPAP compliance.

In order to determine these factors, the investigators have taken into account approximately 450 patients over a timeframe of 5 years who have used a CPAP device during the course of their disorder, and established a Kaplan-Meyer estimation of their survival function. The investigators have then used anthropometry (BMI, neck circumference, sex, age, etc.), polysomnography (Epworth score, AHI, ODI, sleep efficiency, etc.) and CPAP (pressures, leaks, etc.) data with a Cox regression in order to determine the factors that influence the compliance of a patient.

The results will allow us to establish the average compliance of a patient under CPAP therapy, as well as the reasons leading to its termination, the factors predicting a decreased compliance and the consequences of stopping the treatment. This will allow us to set up multiple methods of improved follow-up in patients that are predicted recalcitrant to CPAP therapy.

Inclusion Criteria:

• All HDF patients with OSA, treated for at least one day by CPAP, from the period of June 2008 to June 2013.

Exclusion Criteria:

• None

All patients diagnosed with OSA in the sleep center of Hotel Dieu de France (HDF) hospital, treated for at least one day by CPAP, from the period of June 2008 to June 2013.