1. Department of Gastrointestinal and Hepato‐Biliary‐Pancreatic Surgery Nippon Medical School Tokyo Japan
2. Department of Healthcare Quality Assessment Graduate School of Medicine The University of Tokyo Tokyo Japan
3. Project Management SubcommitteeThe Japanese Society of Gastroenterological Surgery Tokyo Japan
4. Database CommitteeThe Japanese Society of Gastroenterological Surgery Tokyo Japan
5. Department of Surgery Teikyo University Chiba Comprehensive Medical Center Chiba Japan
6. Department of Digestive Tract and General Surgery Saitama Medical University Saitama Japan
7. Department of Coloproctological Surgery Juntendo University Faculty of Medicine Tokyo Japan
8. Department of Surgery 1 University of Occupational and Environmental Health Kitakyushu Japan
9. The Japanese Society of Gastroenterological Surgery Tokyo Japan