1. Department of Internal Medicine Hallym University College of Medicine Chuncheon South Korea
2. Department of Internal Medicine, College of Medicine Ewha Womans University Seoul South Korea
3. Institute of Health & Environment Seoul National University Seoul South Korea
4. Department of Internal Medicine, Digestive Disease Center Inha University College of Medicine Incheon South Korea
5. Department of Internal Medicine Inje University Ilsan Paik Hospital Goyang South Korea
6. Department of Internal Medicine Seoul National University Bundang Hospital Seongnam South Korea
7. Department of Internal Medicine Yonsei University Gangnam Severance Hospital Seoul South Korea
8. Department of Gastroenterology Ajou University School of Medicine Suwon South Korea