1. Department of Pneumology and Intensive Care Medicine and
2. Faculty of Health/School of Medicine, Witten/Herdecke University, Witten, Germany;
3. Medical Clinic II, Department of Pneumology, Cardiology and Intensive Care Medicine, Klinikum Konstanz, Konstanz, Germany;
4. Interdisciplinary Health Science Center, Scuola Superiore Sant’Anna, Pisa, Italy;
5. Department of Cardiology, Vascular Medicine and Intensive Care Medicine, University Hospital RWTH Aachen, Aachen, Germany;
6. Philipps-University of Marburg, German Center for Lung Research, Marburg, Germany; and
7. Institute for Pulmonary Rehabilitation Research, Schoen Klinik Berchtesgadener Land, Schoenau am Koenigssee, Germany