1. Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of California, Los Angeles.
2. Department of Medicine, Division of General Internal Medicine and Health Services Research, University of California, Los Angeles.
3. VA Greater Los Angeles Healthcare System, Los Angeles, California.
4. RAND Health, Santa Monica, California.
5. Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles.
6. Division of Public Health and Community Dentistry, School of Dentistry, University of California, Los Angeles.