1. Division of Gastroenterology and Hepatology; University of Colorado Anschutz Medical Campus; Aurora CO USA
2. Epidemiology; Bloomberg School of Public Health, Johns Hopkins; Baltimore MD USA
3. Divisions of Gastroenterology and Epidemiology; University of California San Diego; La Jolla CA USA
4. Division of Gastroenterology and Hepatology; Saint Louis University; Saint Louis MO USA
5. Department of Pathology and Immunology; Washington University School of Medicine; Saint Louis MO USA
6. Department of Medicine; University of California San Francisco; San Francisco CA USA