1. Department of Medicine, University of California, San Francisco, San Francisco, California, USA;
2. Division of Gastroenterology, San Francisco Veterans Affairs Medical Center, San Francisco, California, USA;
3. Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA;
4. Division of Gastroenterology, Rocky Mountain Regional Veterans Affairs Hospital, Aurora, Colorado, USA;
5. Department of Gastroenterology and Hepatology, Northwestern University, Chicago, Illinois, USA;
6. Biostatistics, Children's Hospital Association, Kansas City, Kansas, USA;
7. Department of Medicine, Division of General Internal Medicine, Washington University School of Medicine at St. Louis, St. Louis, Missouri, USA;
8. Department of Gastroenterology and Hepatology, Singapore General Hospital, Singapore;
9. Division of Gastroenterology, Hepatology and Motility, University of Kansas Medical Center, Kansas City, Kansas, USA; and
10. Northwestern University School of Medicine, Chicago, Illinois, USA.