Association of day of the week with mortality after elective right hemicolectomy for colon cancer: Case analysis from the National Clinical Database

AIM: We aimed to investigate whether later weekdays are related to worse short‐term outcomes after elective right hemicolectomy for colon cancer. METHODS: We retrospectively analyzed adult patients who underwent elective right hemicolectomy for colon cancer between 2012 and 2017. Records lacking details about surgical mortality were excluded, and multiple imputation was performed for other missing data (variables). The primary endpoint was surgical mortality, defined as the sum of 30‐day mortality and in‐hospital deaths within 90 days postoperatively. Using 22 clinical variables, hierarchal logistic regression modeling with clustering of patients from the same institutes was performed. RESULTS: Of the 112 658 patients undergoing elective right hemicolectomy for colon cancer, the 30‐day mortality and surgical mortality were 0.6% and 1.1%, respectively. Surgery on Friday was less frequent, accounting for 17.1% of all cases. The occurrence of severe postoperative complications, anastomotic leakage, or unadjusted odds ratio for surgical mortality did not show significant differences between weekdays. A hierarchal logistic regression model identified 19 independent factors for surgical mortality. Adjusted odds ratios for surgical mortality were 1.01 (95% confidence interval: 0.83‐1.22, P = .915), 0.86 (95% confidence interval: 0.71‐1.05, P = .144), 0.86 (95% confidence interval: 0.71‐1.05, P = .408), and 0.83 (95% confidence interval: 0.68‐1.03, P = .176) for Tuesday, Wednesday, Thursday, and Friday, respectively, showing no significant differences. CONCLUSION: This study did not identify an evident difference in surgical mortality between weekdays; a safe elective right hemicolectomy for colon cancer is being offered throughout the week in Japan.