1. Division of General Medicine and Clinical Epidemiology, Department of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina.
2. Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
3. The Health Initiative, Boston, Massachusetts.
4. Health Leads, Boston, Massachusetts.
5. ZappRx, Boston, Massachusetts.
6. Stanford University School of Medicine, Palo Alto, California.
7. Division of General Internal Medicine, Massachusetts General Hospital, Boston, Massachusetts.
8. Harvard Medical School, Boston, Massachusetts.