1. Division of Gastroenterology and Hepatology , Department of Internal Medicine, Yeouido St. Mary’s Hospital, College of Medicine, , Seoul, 07345 , Republic of Korea
2. The Catholic University of Korea , Department of Internal Medicine, Yeouido St. Mary’s Hospital, College of Medicine, , Seoul, 07345 , Republic of Korea
3. Department of Clinical Epidemiology and Biostatistics , Asan Medical Center, , Seoul, 05505 , Republic of Korea
4. University of Ulsan College of Medicine , Asan Medical Center, , Seoul, 05505 , Republic of Korea
5. Department of Gastroenterology , Liver Center, Asan Medical Center, , Seoul, 05505 , Republic of Korea
6. University of Ulsan College of Medicine , Liver Center, Asan Medical Center, , Seoul, 05505 , Republic of Korea