1. insaf Respiratory Research Institute, Wiesbaden, Germany
2. Department of Respiratory Diseases and Adult Cystic Fibrosis Centre, Hôpital Cochin, AP-HP and Paris Descartes University, Paris, France
3. Department of Research and Education, Centre of Expertise for Chronic Organ Failure, Horn, the Netherlands
4. Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío, Sevilla, Spain
5. Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
6. 2nd Respiratory Medicine Department, National and Kapodistrian University of Athens Medical School, Attiko University Hospital, Athens, Greece
7. University College London Respiratory, University College London, London, United Kingdom
8. University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia
9. Department of Pulmonary Medicine, Hvidovre Hospital, Copenhagen, Denmark
10. Dipartimento di Scienze della Salute, Università degli Studi di Milano, Ospedale San Paolo, Milan, Italy
11. Clinic of Respiratory Medicine and Pulmonary Cell Research, University Hospital Basel, Basel, Switzerland
12. Ludwig-Boltzmann-Institute for Chronic Obstructive Pulmonary Disease and Respiratory Epidemiology, Otto-Wagner-Spital, Vienna, Austria
13. University Hospital, Limerick, Ireland
14. Graduate Entry Medical School, University of Limerick, Limerick, Ireland
15. Department of Public Health and Caring Science, Family Medicine and Preventive Medicine, Uppsala University, Uppsala, Sweden
16. Novartis, Basel, Switzerland; and
17. Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom