1. Group Health Research Institute, Seattle, Washington.
2. Department of Health Services, University of Washington School of Public Health, Seattle, Washington.
3. Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania.
4. Department of Surgery, Office of Health Promotion Research, and the University of Vermont Cancer Center, University of Vermont, Burlington, Vermont.
5. The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire.
6. Departments of Biomedical Science and Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire.
7. Division of General Internal Medicine and Primary Care, Brigham and Women's Hospital, Boston, Massachusetts.
8. Harvard School of Public Health, Boston, Massachusetts.
9. Department of Radiology, University of North Carolina, Chapel Hill, North Carolina.
10. University of New Mexico Cancer Center and School of Medicine, Albuquerque, New Mexico.
11. Department of Radiology, University of Washington School of Medicine, Seattle, Washington.
12. Fred Hutchinson Cancer Research Center, Hutchinson Institute for Cancer Outcomes Research, Seattle, Washington.
13. Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire.