1. Institute for Pulmonary Rehabilitation Research, Schoen Klinik Berchtesgadener Land, 83471 Schoenau am Koenigssee, Germany
2. Department of Medicine V, Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research (DZL), Ludwig-Maximilians University (LMU) University Hospital, 81377 Munich, Germany
3. Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, 8010 Graz, Austria
4. Department of Pulmonary Rehabilitation, Universities of Giessen and Marburg Lung Center (UGMLC), German Center for Lung Research (DZL), Philipps-University of Marburg, 35043 Marburg, Germany
5. Teaching Hospital, Paracelsus Medical University Salzburg, 5020 Salzburg, Austria