1. Department of Pneumology Medical Center University of Freiburg Faculty of Medicine University of Freiburg Freiburg Germany
2. Section of Pulmonary, Critical Care and Sleep Medicine Yale University School of Medicine New Haven CT USA
3. Medical Hospital Research Center Borstel Sülfeld Germany
4. Department of Respiratory Medicine Hannover Medical School Hannover Germany
5. Institute for Medical Biometry and Statistics Center for Medical Biometry and Medical Informatics Medical Center – University of Freiburg Freiburg Germany