1. Centre for Sleep and Vigilance Disorders; Department of Internal Medicine and Clinical Nutrition; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
2. Sleep Disorders Centre; Department of Cardiology; Istituto Auxologico Italiano IRCCS; Milan Italy
3. Pulmonary and Sleep Disorders Unit; University College Dublin; St Vincent's University Hospital; Dublin Ireland
4. Charite-Universitaetsmedizin Berlin; Berlin Germany
5. Department of Sleep Medicine; Royal Infirmary of Edinburgh; Edinburgh UK
6. Center for Sleep Medicine and Pneumology Department; Cliniques universitaires Saint-Luc; Université catholique de Louvain; Brussels Belgium