1. Medical Data Research Collaborative , London , UK
2. Department of Medicine, Mount Auburn Hospital , Cambridge, MA , USA
3. Harvard Medical School , Boston, MA , USA
4. Division of Pulmonary and Critical Care Medicine, Lahey Hospital , Burlington, MA , USA
5. Warwick Clinical Trials Unit, University of Warwick , Coventry , UK
6. Oxford University Hospitals NHS Foundation Trust , Oxford , UK
7. National Heart and Lung Institute, Imperial College London , London , UK
8. Division of Pulmonary and Critical Care, Brigham and Women’s Hospital , Boston, MA , USA
9. Department of Surgery and Cancer, Imperial College London , London , UK
10. Imperial Vascular Unit, Imperial College Healthcare NHS Trust , London , UK