1. Pulmonary Division; University Hospital of Zurich; Zurich Switzerland
2. Institut of General Practice and Health Services Research; University of Zurich; Zurich Switzerland
3. Pulmonary Division; Cantonal Hospital of Glarus; Glarus Switzerland
4. Pulmonary Division; Cantonal Hospital of St Gallen; St Gallen Switzerland
5. Pulmonary Division; Clinic Barmelweid; Barmelweid Switzerland
6. Pulmonary Division; Cantonal Hospital of Aarau; Aarau Switzerland
7. University Clinic of Internal Medicine; Cantonal Hospital Basel and University of Basel; Basel Switzerland
8. Pulmonary Division; Cantonal Hospital of Münsterlingen; Münsterlingen Switzerland
9. Zurich Centre for Integrative Human Physiology; University of Zurich; Zurich Switzerland