1. University of Kansas Medical Center, Internal Medicine Department, Division of Gastroenterology and Hepatology, Kansas City, Kansas, USA
2. University of Toledo Medical Center, Department of Internal Medicine, Toledo, Ohio, USA
3. Washington University School of Medicine, Internal Medicine Department, Division of Gastroenterology and Hepatology, St. Louis, Missouri, USA
4. Mayo Clinic College of Medicine, Evidence-Based Practice Center, Rochester, Minnesota, USA
5. Northwestern University Feinberg School of Medicine, Internal Medicine Department, Division of Gastroenterology and Hepatology, Chicago, Illinois, USA