1. Center for Care Delivery and Outcomes Research, Minneapolis VA Health Care System, Minnesota
2. Department of Medicine, Division of General Internal Medicine, University of Minnesota Medical School, Twin Cities
3. Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis
4. Center for Aging and Population Health and Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania
5. Research Institute, California Pacific Medical Center, San Francisco
6. Department of Epidemiology and Biostatistics, University of California, San Francisco
7. Intramural Research Program, National Institute on Aging, Baltimore, Maryland
8. Department of Health Management and Policy, College of Public Health, University of Kentucky, Lexington