1. Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado.
2. Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado.
3. RAND Corporation, Santa Monica, California.
4. Department of Health Policy and Management, UCLA Fielding School of Public Health, Los Angeles, California.
5. Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California.
6. Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, California.
7. Division of Geriatrics, Department of Medicine, University of California, San Francisco, San Francisco, California.
8. San Francisco Veterans Affairs Medical Center, San Francisco, California.