1. Department of Internal Medicine, Chungbuk National Unviersity College of Medicine, Cheongju, Korea.
2. The Epidemiology Study Group of the Korean Association for the Study of the Liver, Seoul, Korea.
3. Department of Pediatrics, The Catholic University of Korea, Seoul, Korea.
4. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Korea University Medical College, Seoul, Korea.