1. The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth College, Lebanon, New Hampshire, USA.
2. Dartmouth Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA.
3. Kaiser Permanente Washington Health Research Institute, Kaiser Permanente Washington, Seattle, Washington, USA.
4. Division of General Internal Medicine, Department of Medicine, University of California, San Francisco, San Francisco, California, USA.
5. Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
6. Department of Surgery, University of Vermont Cancer Center, University of Vermont, Burlington, Vermont, USA.
7. Department of Population Health Science, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA.
8. Department of Public Health Sciences, University of California, Davis, California, USA.
9. Departments of Medicine and Epidemiology and Biostatistics, University of California, San Francisco, California, USA.