Days of the week and 90-day mortality after esophagectomy: analysis of 33,980 patients from the National Clinical Database

Purpose: The effect of the days of the week on the short-term outcomes after elective surgeries has been suggested; however, such data on esophagectomies remain limited. This study aimed to investigate the association between the day of the week and mortality rates after elective esophagectomy using a large-scale clinical database in Japan. Methods: The data of elective esophagectomies, registered in the National Clinical Database in Japan, for esophageal cancer treatment between 2012 and 2017 were analyzed. We hypothesized that the later days of the week could have higher odds ratios of death after elective esophagectomy. With 22 relevant clinical variables and days of surgery, 90-day mortality was evaluated using hierarchical logistic regression modeling. Results: Ninety-day mortality rates among 33,980 patients undergoing elective esophagectomy were 1.8% (range, 1.5–2.1%). Surgeries were largely concentrated on earlier days of the week, whereas esophagectomies performed on Fridays accounted for only 11.1% of all cases. Before risk adjustment, lower odds ratios of 90-day mortality were found on Tuesday and a tendency towards lower odds ratios on Thursday. In the hierarchical logistic regression model, 21 independent factors of 90-day mortality were identified. However, the adjusted odds ratios of 90-day mortality for Tuesday, Wednesday, Thursday, and Friday were 0.87, 1.09, 0.85, and 0.88, respectively, revealing no significant difference. Conclusion: The results imply that the variation in 90-day mortality rates after esophagectomy on different days of the week may be attributed to differing preoperative risk factors of the patient group rather than the disparity in medical care provided.