1. Center for Advanced IBD Research and Treatment, Kitasato University Kitasato Institute Hospital, Tokyo,Japan
2. Department of Gastroenterology and Hepatology, Kitasato University Kitasato Institute Hospital, Tokyo,Japan
3. Department of Healthcare Epidemiology, School of Public Health in the Graduate School of Medicine, Kyoto University, Kyoto,Japan
4. Section of Clinical Epidemiology, Department of Community Medicine, Graduate School of Medicine, Kyoto University, Kyoto,Japan
5. Department of Gastroenterology and Hepatology, Showa University Fujigaoka Hospital, Kanagawa,Japan