1. Department of Family Medicine, Chung-Ang University Gwangmyeong Hospital, Chung-Ang University College of Medicine, Gwangmyeong, South Korea
2. Department of Family Medicine, Jeju National University Hospital, Jeju National University College of Medicine, Jeju, South Korea
3. Department of Biomedical Informatics, CHA University School of Medicine, Seongnam, South Korea
4. Department of Biomedical Sciences, Seoul National University, Seoul National University College of Medicine, Seoul, South Korea
5. Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
6. Department of Family Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.