1. CIRO+, Centre of expertise for chronic organ failure, Horn, the Netherlands;
2. Department of Respiratory Medicine, MUMC+, Maastricht University Medical Centre, Maastricht, the Netherlands;
3. Department of Respiratory Medicine, AZ Sint-Lucas, Gent, Belgium;
4. Department of Pneumology, Paracelsus Medical University, Salzburg, Austria;
5. Kaiser Permanente Center for Health Research, Portland, OR, USA;
6. Department of Pulmonary Medicine, Kepler-University-Hospital, Linz, Austria;
7. Faculty of Medicine, Johannes-Kepler-University, Linz, Austria;
8. Respiratory Epidemiology, Occupational Medicine and Public Health, National Heart and Lung Institute, Imperial College, London, UK;
9. COPD Center, Sahlgrenska University Hospital, Institute of Medicine, Gothenburg University, Gothenburg, Sweden