The Effect of Day of the Week on Morbidity and Mortality From Colorectal and Pancreatic Surgery.

Background: A number of studies have revealed higher postoperative mortality after operations that were performed toward the end of the week. It is not yet known whether a day-of-the-week effect exists after visceral surgical procedures for cancer in Germany.

Methods: Data on resections of carcinomas of the colon, rectum (2010-2017), and head of the pancreas (2014-2017) (n = 19 703) that had been prospectively acquired by the Study, Documentation, and Quality Center of the German Society for General and Visceral Surgery were analyzed in relation to the day of the week on which the operation was performed. The primary endpoint was postoperative 30-day mortality; the secondary endpoints were complications, length of hospital stay, and MTL30 (a combined outcome criterion that is positive if the patient has died, is still in the hospital, or has been transferred to another acute care hospital 30 days after the index procedure).

Results: Resections of colon carcinomas that were performed on Mondays were associated with more advanced tumor stages (T4: 18.4% vs. 15.7%, p <0.001), higher 30-day mortality (3.5% vs. 2.3%, p = 0.004), and a more frequently positive MTL30 (10.5% vs. 8.5%, p = 0.004). Among patients who underwent pancreatic head resections, those whose procedures were on Tuesday had higher mortality (6.2% vs. 3.8%; p = 0.021). Among those who underwent surgery for rectal carcinoma, the day of the week on which the procedure was performed had no effect on postoperative morality. Multivariate analysis revealed that the independent risk factors for postoperative mortality were colonic resection on a Monday (odds ratio [OR]: 1.45; 95% confidence interval [1.11; 1.92], p = 0.008) and pancreatic head resection on a Tuesday (OR: 1.88 [1.18; 2.91], p = 0.006).

Conclusion: Elective surgery for carcinoma of the colon or pancreatic head is associated with slightly higher mortality if per - formed toward the beginning of the week. On the other hand, the day of the week has no effect on the outcome of surgery for rectal carcinoma.