1. Center for Health Services Research in Primary Care, Durham Veterans Affairs Health Care System, Durham, North Carolina.
2. Department of Population Health Sciences, Duke University Medical Center, Durham, North Carolina.
3. Division of General Internal Medicine, Duke University Medical Center, Durham, North Carolina.
4. VA Cooperative Studies Program Epidemiology Center, Durham Veterans Affairs Health Care System, Durham, North Carolina.
5. Division of Medical Oncology, Duke University Medical Center, Durham, North Carolina.
6. Radiation Oncology Service, Richmond Veterans Affairs Medical Center, Richmond, Virginia.
7. Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina.
8. Departments of Psychiatry and School of Nursing Duke University, Durham, North Carolina.
9. Department of Veterans Affairs, Specialty Care Services, Washington, District of Columbia.
10. Hematology-Oncology Service, Durham Veterans Affairs Health Care System, Durham, North Carolina.