Variation in hospital performances after colorectal cancer surgery: A case-mix adjusted Dutch population based study

Background: This study aimed to investigate hospital variability in postoperative mortality and anastomotic leakage (AL) after colorectal cancer surgery, as well as the association with hospital volume and teaching status. Materials and methods: This nationwide population based study derived data from CRC patients who underwent a surgical resection with primary anastomosis from the Netherlands Cancer Registry between 2015 and 2020. Primary outcomes were 90 -day mortality and AL for colon cancer (CC) patients, and AL for rectal cancer (RC) patients. Logistic regression modelling was used to evaluate the association between case -mix factors and hospital volume. Variability in outcomes between hospitals was analysed with Poisson regression. Results: This study included 44,101 CRC patients, comprising 35,164 CC patients, and 8937 RC patients. In the CC cohort, the unadjusted rates of AL ranged from 2.6 % to 14.4 %, and the unadjusted 90 -day mortality rates ranged from 0.0 % to 6.7 %. In the RC cohort, the unadjusted rates of AL ranged from 0.0 % to 28.6 %. After case -mix adjustment, two hospitals performed significantly worse than expected regarding 90 -day mortality in the CC cohort, and in both CC and RC cohorts, significant outliers were observed concerning AL. Amongst CC patients, low case volume (OR 1.26 95%CI 1.08-1.46) was significantly associated with AL. Conclusion: Statistically significant variations in hospital performance were observed among Dutch hospitals after CRC surgery, but this effect could not be entirely attributed to hospitals' teaching status. Nevertheless, concentrating care has the potential to improve outcomes by enhancing individual surgical performance and optimizing care pathways.