1. Department of Internal Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
2. Department of Statistics, Keimyung University, Daegu, Korea
3. Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
4. Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
5. Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Gangwon-do, Korea
6. Division of Gastroenterology, Department of Internal Medicine, College of Medicine, Konyang University, Daejeon, Korea
7. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
8. Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea
9. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
10. Department of Internal Medicine, Daegu Catholic University School of Medicine, Daegu, Korea
11. Department of Internal Medicine, Dongguk University College of Medicine, Goyang, Gyeonggi-do, Korea
12. Departments of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
13. Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
14. Department of Internal Medicine, Soonchunhyang University, Bucheon, Gyeonggi-do, Korea
15. Health Promotion, Gangnam Severance Hospital, Seoul, Korea
16. Department of Gastroenterology, Wonkwang University School of Medicine, Iksan, Jeollabuk-do, Korea
17. Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea
18. Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Gyeongsangnam-do, Korea
19. Department of Gastroenterology, Ajou University School of Medicine, Suwon, Gyeonggi-do, Korea