1. Health Services Research and Development, Veterans Affairs Puget Sound Healthcare System, Seattle Division, Seattle, Washington;
2. Division of Pulmonary, Critical Care, and Sleep Medicine, University of Washington, Seattle, Washington;
3. Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, Colorado;
4. Department of Medicine and
5. Epidemiology Data Center, School of Public Health, and
6. Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania;
7. National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland;
8. Department of Pulmonary and Critical Care Medicine, Geisinger Medical Center, Danville, Pennsylvania;
9. Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep, Minneapolis Veterans Affairs Healthcare System, Minneapolis, Minnesota;
10. Department of Thoracic Medicine and Surgery, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania;
11. Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, East Carolina University, Greenville, North Carolina
12. Division of Academic Internal Medicine and Geriatrics, University of Illinois Chicago, Chicago, Illinois;