1. Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea
2. Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Gyeongsangnam-do, Korea
3. Department of Internal Medicine, Eunpyeong St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
4. Department of Internal Medicine, College of Medicine, Bucheon St. Mary's Hospital, The Catholic University of Korea, Bucheon, Gyeonggi-do, Korea
5. Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea
6. Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Chungcheongnam-do, Korea
7. Division of Gastroenterology, Department of Internal Medicine, CHA Ilsan Medical Center, CHA University School of Medicine, Goyang, Gyeonggi-do, Korea
8. Department of Internal Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, Gyeonggi-do, Korea
9. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
10. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
11. Department of Internal Medicine, Inje University Ilsan Paik Hospital, Goyang, Gyeonggi-do, Korea
12. Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
13. Department of Internal Medicine, Daegu Catholic University School of Medicine, Daegu, Korea