1. Primary Health Care of the Capital Area, Department of Family Medicine , Reykjavik , Iceland
2. Faculty of Medicine, Department of Medicine, University of Iceland , Reykjavik , Iceland
3. Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
4. Sleep Department, Landspitali - The National University Hospital of Iceland , Reykjavik , Iceland
5. Department of Medicine, Corporal Michael J. Crescenz VA Medical Center , Philadelphia, PA , USA
6. Interdisciplinary Center of Sleep Medicine, Charité University Hospital , Berlin , Germany
7. Department of Respiratory and Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China
8. Charles Perkins Centre, Faculty of Medicine and Health, University of Sydney , Sydney, NSW , Australia
9. Department of Respiratory and Sleep Medicine, Royal North Shore Hospital , Australia
10. Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center , Columbus, OH , USA
11. Western Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital , Nedlands, WA , Australia
12. Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital , Nedlands, WA , Australia
13. Department of Medical Sciences: Respiratory, Allergy and Sleep Research, Uppsala University , Uppsala , Sweden
14. Icelandic Heart Association , Kopavogur , Iceland
15. Sleep disorders center, Department of Medicine, University of Manitoba , Winnipeg, MB , Canada
16. Charles Perkins Centre, Faculty of Engineering, University of Sydney , Sydney , Australia
17. Department of Psychobiology, Universidade Federal de São Paulo , São Paulo , Brazil