1. Department of Medicine, Division of Gastroenterology University of Pittsburgh Medical Center Pittsburgh Pennsylvania USA
2. Department of Biostatistics University of Pittsburgh Pittsburgh Pennsylvania USA
3. MedStar Washington Hospital Center Washington District of Columbia USA
4. Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition University of Pittsburgh, UPMC Pittsburgh Pennsylvania USA
5. Division of Gastroenterology John Hopkins Medical Institution Baltimore Maryland USA
6. Cleveland Clinic Foundation Cleveland Ohio USA
7. Eastern Maine Medical Center Bangor Maine USA
8. Division of Gastroenterology Indiana University School of Medicine Indianapolis Indiana USA
9. Division of Gastroenterology West Virginia University Morgantown West Virginia USA
10. Division of Gastroenterology Medical University of South Carolina Charleston West Virginia USA
11. Division of Gastroenterology, Department of Medicine Hospital of the University of Pennsylvania Philadelphia Pennsylvania USA
12. Division of Gastroenterology University of Pittsburgh Medical Center Pittsburgh Pennsylvania USA
13. Division of Gastroenterology Mayo Clinic Healthcare System Eau Claire Wisconsin USA
14. Division of Gastroenterology, Department of Internal Medicine University of Southern California Keck School of Medicine Los Angeles California USA
15. Division of Gastroenterology, Hepatology, and Nutrition Ohio State University, Wexner Medical Center Columbus Ohio USA
16. Division of Gastroenterology Kaiser Permanente Pasadena California USA