1. Division of General Medicine and Clinical Epidemiology, Department of Medicine, University of North Carolina at Chapel Hill School of Medicine
2. Center for Health Equity Research, Department of Social Medicine, School of Medicine, University of North Carolina at Chapel Hill
3. Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill
4. Division of General Internal Medicine, Massachusetts General Hospital, Boston
5. Community Servings, Inc, Boston, Massachusetts
6. Massachusetts Department of Public Health, Boston
7. Mongan Institute, Massachusetts General Hospital, Boston
8. Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts