1. Durham University, Durham, United Kingdom;
2. Institute of Applied Health Research, Birmingham, United Kingdom;
3. Department of Medicine, University of Cambridge, Cambridge, United Kingdom;
4. Royal Papworth Hospital, Cambridge, United Kingdom;
5. University of California, San Diego, San Diego, California;
6. Hospital Clinic, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Centro de Investigación Biomédica en Red Enfermedades Respiratorias, University of Barcelona, Barcelona, Spain;
7. Amsterdam University Medical Center, Amsterdam, the Netherlands;
8. University Hospitals Leuven, Leuven, Belgium;
9. Hammersmith Hospital, London, United Kingdom;
10. Vienna General Hospital, Medical University of Vienna, Vienna, Austria;
11. Kerckhoff Clinic, Bad Nauheim, Germany;
12. Imperial College London, London, United Kingdom;
13. King’s College London, London, United Kingdom; and
14. St. George’s, University of London, London, United Kingdom