1. Division of Pulmonary and Critical Care Medicine and
2. Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland;
3. Division of Pediatric Pulmonary and Sleep Medicine and
4. Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois, Chicago, Illinois;
5. Department of Medicine and
6. Department of Physiology, School of Medicine, University of California, Los Angeles, Los Angeles, California;
7. Division of Pulmonary and Critical Care, School of Medicine, University of Utah, Salt Lake City, Utah;
8. Division of Pulmonary and Critical Care, National Jewish Health, Denver, Colorado;
9. Department of Radiology, Medicine and Biomedical Engineering, University of Iowa, Iowa City, Iowa;
10. Division of Pulmonary and Critical Care, Temple University Hospital, Philadelphia, Pennsylvania;
11. Division of Pulmonary and Critical Care Presbyterian Hospital, Columbia University Medical Center, New York, New York;
12. Department of Internal Medicine, Weill Cornell Medical College, New York, New York;
13. Division of Pulmonary and Critical Care, University of Michigan Health System, Ann Arbor, Michigan;
14. Center for Genomics and Personalized Medicine Research, Wake Forest University, Winston-Salem, North Carolina;
15. Division of Pulmonary and Critical Care, University of Alabama at Birmingham, Birmingham, Alabama;
16. Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, University of California, San Francisco, San Francisco, California;
17. Department of Environmental and Occupational Health Sciences,
18. Department of Medicine, and
19. Department of Epidemiology, University of Washington, Seattle, Washington; and
20. Section of Pulmonary and Critical Care, Dartmouth-Hitchcock Medical Center, Geisel School of Medicine, Hanover, New Hampshire