1. Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
2. Division of Gastroenterology, Chulalongkorn University, King Chulalongkorn Memorial, Hospital, Thai Red Cross Society, Bangkok, Thailand
3. Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
4. Division of Gastroenterology and Hepatology, Mayo Clinic, 200 First Street SW, Rochester MN 55905, USA