1. Division of Pulmonary and Critical Care Medicine, University of Utah, Salt Lake City
2. VA Salt Lake City Health Care System, Salt Lake City, Utah
3. Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts
4. Division of Epidemiology, University of Utah, Salt Lake City
5. HCA Healthcare Inc, Nashville, Tennessee
6. Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
7. Department of Medicine, Brigham Women’s Hospital, Boston, Massachusetts