1. Center for Advanced Endoscopy Division of Gastroenterology Beth Israel Deaconess Medical Center and Harvard Medical School BostonUSA
2. Division of Gastroenterology University of Michigan Health System University of Michigan Ann ArborUSA
3. Digestive Disease Center Showa University Northern Yokohama Hospital Kanagawa Japan
4. Clinical Effectiveness Research Group Institute of Health and Society University of Oslo Oslo Norway
5. Department of Gastroenterology and Hepatology University of Kansas Medical Center Kansas CityKSUSA
6. Department of Gastroenterology Kansas City VA Medical Center Kansas City USA