1. Sleep Disorders Center and Pulmonary Division University Hospital Zurich Zurich Switzerland
2. Sleep Disorders Center and Pulmonary Division Kantonsspital Graubuenden Chur Switzerland
3. Department of General Internal Medicine University Hospital Bern, University of Bern Bern Switzerland
4. Institute of Primary Health Care (BIHAM) University of Bern Bern Switzerland
5. Zurich Center for Interdisciplinary Sleep Research University of Zurich Zurich Switzerland
6. Department of Internal Medicine Cantonal Hospital Baden Baden Switzerland