1. Department of Medicine Landspitali ‐ The National University Hospital of Iceland Reykjavik Iceland
2. Faculty of Medicine University of Iceland Reykjavik Iceland
3. Sleep Department Landspitali ‐ The National University Hospital of Iceland Reykjavik Iceland
4. School of Science and Engineering Reykjavik University Reykjavik Iceland
5. Department of Medical Sciences: Respiratory Allergy and Sleep Research Uppsala University Uppsala Sweden
6. Icelandic Heart Association Kopavogur Iceland
7. Department of Medicine and Center for Sleep and Circadian Neurobiology Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania USA
8. Department of Medicine Corporal Michael J. Crescenz VA Medical Center Philadelphia Pennsylvania USA
9. Internal Medicine Services Landspitali ‐ The National University Hospital of Iceland Reykjavik Iceland