1. Center for Research on Health Care, Division of General Internal Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
2. Department of Health Policy and Management, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
3. Center for Learning Health Care, Duke Clinical Research Institute, Duke University School of Medicine, Duke University Medical Center, Durham, North Carolina.
4. Division of Medical Oncology, Duke University School of Medicine, Duke University Medical Center, Durham, North Carolina.
5. Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
6. Phoenix VA Health Care System, Phoenix, Arizona.
7. Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, North Carolina.