1. Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, University of Washington, Seattle, Washington, USA;
2. Department of Health Services, School of Public Health and Community Medicine, University of Washington, and Department of Biostatistics, School of Public Health and Community Medicine, University of Washington, Seattle, Washington, USA;
3. School of Naturopathic Medicine, Bastyr University, Kenmore, Washington;
4. Department of Health Services, School of Public Health and Community Medicine, University of Washington, Seattle, Washington, USA;
5. Northwest Health Services Research & Development Service Center of Excellence, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, USA;
6. Fred Hutchinson Cancer Research Center, Seattle, Washington, USA;
7. Bastyr University Research Center, Kenmore, Washington;
8. Office of Health Services and Public Health Outcomes Research, Department of Informatics, School of Medicine, University of Missouri (Kansas City), Kansas City, Missouri, USA.