1. Department of Internal Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
2. Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
3. Department of Statistics and Actuarial Science, Soongsil University, Seoul, Korea
4. Department of Medical Statistics, College of Medicine, The Catholic University of Korea, Seoul, Korea
5. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
6. Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea