The data were verified by on-site auditing, and data cleaning was performed by R software. 
R software
Based on the Hospital Information System (HIS)of 20 medical centers in China, the electronic case reporting form (e-CRF) listed on the website was used to collect medical information of patients undergoing gastric or colorectal cancer surgery. 
Hospital Information System (HIS)
Based on the Hospital Information System (HIS)of 20 medical centers in China, the electronic case reporting form (e-CRF) listed on the website was used to collect medical information of patients undergoing gastric or colorectal cancer surgery. 
e-CRF