1. Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
2. College of Pharmacy, Chung-Ang University, Seoul, Korea.
3. Department of Global Innovative Drugs, The Graduate School of Chung-Ang University, Seoul, Korea.
4. Division of Gastroenterology, Department of Internal Medicine and Gastrointestinal Cancer Center, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
5. Division of Gastroenterology, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
6. Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
7. Division of Gastroenterology, Department of Internal Medicine, Inje University Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
8. Department of Internal Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
9. Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.