1. First Department of Respiratory and Critical Care Medicine and Ludwig Boltzmann Institute for COPD and Respiratory Epidemiology, Otto Wagner Hospital
2. Second Department of Respiratory Medicine, Otto Wagner Hospital
3. First Department of Respiratory and Critical Care Medicine and Ludwig Boltzmann Institute for COPD and Respiratory Epidemiology, Otto Wagner Hospital, and Sigmund Freud University, Medical School
4. Respiratory Institute, Hospital Clinic, IDIBAPS, University of Barcelona and National Spanish Network for Respiratory Research (CIBERES)
5. Institute of Public Health, Environmental and Occupational Medicine, Aarhus University
6. Department of Medicine, Pulmonary and Critical Care Medicine, University Medical Center Giessen and Marburg, Philipps-University Marburg
7. Department of Respiratory Medicine+, MUMC+, Maastricht University
8. Department of Respiratory Medicine, Paracelsus Medical University