1. Center for Health Services Research in Primary Care, Durham Veterans Affairs Health Care System, 508 Fulton Street, Durham, NC 27705.
2. Division of General Internal Medicine, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710.
3. Cooperative Studies Program Epidemiology Center, Durham Veterans Affairs Health Care System, 508 Fulton Street, Durham, NC 27705.
4. Division of Medical Oncology, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710.
5. Division of Gastroenterology, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710.
6. Specialty Care Services, Department of Veterans Affairs, 810 Vermont Avenue, Washington, DC 20420.
7. Hematology-Oncology Service, Durham Veterans Affairs Health Care System, 508 Fulton Street, Durham, NC 27705.