1. Department of Medicine, Boston University School of Medicine, Boston, MA, USA
2. American Thoracic Society, New York, New York, USA
3. Department of Medicine, Beth Israel Deaconess Medicine Center, Boston, Massachusetts, USA
4. Denver Public Health, University of Colorado School of Medicine, Denver, Colorado, USA
5. Veterans Affairs Puget Sound Healthcare System and Department of Medicine, University of Washington, Seattle, Washington, USA
6. Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
7. Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
8. Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
9. Royal Perth Hospital, University of Western Australia, Perth, Australia
10. Respiratory Institute, Cleveland Clinic, Cleveland, Ohio, USA