1. Department of Internal Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
2. Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
3. Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
4. Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Jinju, Gyeongsangnam-do, Korea
5. Department of Internal Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
6. Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea
7. Department of Internal Medicine, CHA Ilsan Medical Center, CHA University, School of Medicine, Goyang, Gyeonggi-do, Korea
8. Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Chungcheongnam-do, Korea
9. Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea
10. Department of Internal Medicine, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
11. Department of Gastroenterology, Seoul National University Bundang Hospital, Bundang, Gyeonggi-do, Korea