The study is based on the assumption that in the Overlap Syndrome, the introduction at home of the NIV is as effective in terms of compliance and clinical and gazometric improvement, and life quality, that setting hospital start up. The investigators will study the initiation of NIV at home versus in hospital in two randomized Overlap Syndrome patient groups. The main objective of the study is to demonstrate the non-inferiority of the initiation of the NIV at home versus hospital in terms of compliance.

The Overlap Syndrome is defined by the coexistence of chronic obstructive pulmonary disease (COPD) and an apnea - hypopnea syndrome obstructive sleep (SAHS). The interaction between these two diseases is responsible for deepest nocturnal desaturation, decreased sensitivity to CO2, more pronounced sleep alterations, more frequent daytime hypercapnia, a higher risk of hypertension pulmonary and increased cardiovascular risk, compared to subjects with COPD or isolated SAHS.

The Overlap Syndrome treatments are continuous positive airway pressure (CPAP) or non-invasive ventilation (NIV), associated complemented or not by oxygen therapy during sleep. The criteria for choosing the type of treatment are not well defined. Quality and compliance of the NIV are very important in all diseases leading to chronic respiratory failure whose Overlap Syndrome. The increase in the number of patients treated with NIV is estimated at over 12% per year. The NIV startup is usually performed in a conventional hospitalization but congestion healthcare pathways lead to increase waiting time before treatment. Thus, to date, no study has validated a supported alternative to meet the increase in the number of patients on NIV while maintaining quality service.

The HAS has defined good candidates for a NIV home based startup, on the following criteria: patients with a recognized indication of NIV in the long term , with stable respiratory failure, requiring only nocturnal ventilation, surrounded by caregivers mastering the use of equipment and whose location allows rapid intervention. The study is based on the assumption that in the Overlap Syndrome, the introduction at home of the NIV is as effective in terms of compliance and clinical and gazometric improvement, and life quality, that setting hospital start up. The investigators will study the initiation of NIV at home versus in hospital in two randomized Overlap Syndrome patient groups. The main objective of the study is to demonstrate the non-inferiority of the initiation of the NIV at home versus hospital in terms of compliance.

Inclusion Criteria:

• Major patients, of less than 80 years
• Patients with chronic respiratory failure within a Overlap syndrome ( defined by the coexistence of COPD and OAS ) in stable situation (no exacerbation for at least 4 weeks) , indication for a NIV treatment
• OAS confirmed by polysomnography according to the standards of the American Academy of Sleep Medicine ( AASM ) with an AHI> 15, the central apneas are tolerated if < 20%
• COPD defined by obstruction of the air flow : VEMS/CVF <70 % and VEMS <80% of the average value predicted
• Started criteria of NIV: chronic respiratory failure within an Overlap Syndrome and PaCO2 > 45 mmHg (at rest on room air ) and / or medium PtCO2 > 50 mmHg
• Patient informed of the study and who signed an informed consent

Exclusion Criteria:

• Patients already treated for OAS in the year
• Patient tracheotomised
• Other diseases with respiratory involvement : neuromuscular disease , restrictive disease of the chest with CPT <80% , apnea syndrome pure central sleep ( central apnea are tolerated if < 20% )
• Lung cancer within the last 5 years
• Uncontrolled psychic diseases
• Acute respiratory failure requiring NIV , going back a month
• Clinical situation requiring prolonged hospitalization
• Patients with no opportunity to understand and follow instructions
• Refusal to participate in the study
• Lack of insurance coverage
• Pregnant and / or nursing