1. Division of General Medicine, Department of Medicine, Brigham and Women's Hospital, Department of Health Care Policy, Harvard Medical School, Boston, MA
2. Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA
3. Department of Ambulatory Care and Prevention, Harvard Medical School/Harvard Pilgrim Health Care, Boston, MA
4. Division of Preventive Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
5. Departments of Biostatistical Science and Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
6. RAND, Santa Monica, CA, and Divisions of General Internal Medicine–Health Services Research and Hematology-Oncology, Department of Medicine, University of California Los Angeles, Los Angeles, CA
7. Division of Cancer Control and Population Sciences, National Cancer Institute, Rockville, MD
8. Department of Veterans Affairs Medical Center, Durham, NC
9. Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina, Chapel Hill, NC
10. Department of Veterans Affairs Medical Center, Minneapolis, MN
11. Northern California Cancer Center, Union City, CA