1. Department of General Surgery, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University
2. Data and Statistics Division, Department of Critical Care Medicine, Jinling Hospital
3. Department of Biostatistics, Public Health School, Nanjing Medical University, Nanjing
4. Department of Hepatobiliary Pancreatic Surgery, Changhai Hospital, the Second Military Medical University
5. Department of General Surgery, First Affiliated Hospital of Kunming Medical University, Kunming
6. Department of Gastrointestinal Surgery, the Affiliated Hospital of Qingdao University, Qingdao
7. Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University, Haerbin
8. Department of General Surgery, the Second Affiliated Hospital, Army Medical University, Chongqing
9. Department of Gastrointestinal Surgery, the First Affiliated Hospital of Air Force Medical University, Xi’an
10. Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
11. Department of General Surgery, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, Shanghai
12. Department of General Surgery, First Medical Center of Chinese PLA General Hospital, Beijing
13. Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, China