1. Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA;
2. Division of Gastroenterology, Department of Medicine, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA;
3. Division of Gastroenterology, Department of Medicine, White River Junction VAMC, White River Junction, Vermont, USA;
4. University of Connecticut School of Medicine, Farmington, Connecticut, USA;
5. Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA;
6. Department of Medicine, Section of Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA;
7. New Hampshire Colonoscopy Registry, Lebanon, New Hampshire, USA;
8. Division of Gastroenterology, Department of Medicine, University of California San Francisco, San Francisco, California, USA;
9. Chief Medical Officer, University of California San Francisco Health System, San Francisco, California, USA;
10. Division of Gastroenterology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA;
11. VA Puget Sound Health Care System, Seattle, Washington, USA;
12. Department of Medicine, University of California, San Francisco, California, USA;
13. Division of Gastroenterology, San Francisco Veterans Affairs Medical Center, San Francisco, California, USA;
14. Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA;
15. Kaiser Permanente Division of Research, Pleasonton, California, USA;
16. Division of Gastroenterology, Department of Medicine, NYU Grossman School of Medicine, New York Harbor Veterans Affairs Health Care System, New York, New York, USA;
17. Department of Gastroenterology, Hepatology and Nutrition, Digestive Diseases Institute, Cleveland Clinic, Cleveland, Ohio, USA;
18. Division of Gastroenterology and Hepatology, Mayo Clinic Florida, Jacksonville, Florida, USA;
19. Division of Gastroenterology and Hepatology, Mayo Clinic Rochester, Rochester, Minnesota, USA;
20. Division of Gastroenterology and Hepatology, University of North Carolina, Chapel Hill, North Carolina, USA.