[1] Univ Hosp Santa Maria, Pneumol, CHLN, Lisbon, Portugal
[2] Gothenburg Univ, Sahlgrenska Univ Hosp, Dept Sleep Med, Gothenburg, Sweden
[3] Turku Univ Hosp, Dept Pulm Dis, Turku, Finland
[4] Ege Univ, Dept Chest Dis, Izmir, Turkey
[5] G Papanikolaou Hosp, Resp Failure Unit, Thessaloniki, Greece
[6] Royal Infirm Edinburgh NHS Trust, Dept Sleep Med, Edinburgh, Midlothian, Scotland
[7] CNR, Inst Biomed & Mol Immunol, Palermo, Italy
[8] St Vincents Univ Hosp, Dept Resp Med, Dublin, Ireland
[9] Univ Coll Dublin, Sch Med, Dublin, Ireland
[10] Univ Crete, Sleep Disorders Ctr, Sch Med, Iraklion, NE, Greece
[11] Univ Palermo, Biomed Dept Internal & Specialist Med DiBiMIS, Sect Pneumol, Palermo, Italy
[12] Antwerp Univ Hosp, Sleep Disorders Ctr, Antwerp, Belgium
[13] Univ Antwerp, Antwerp, Belgium