An interventional nationwide surveillance program lowers postoperative infection rates in elective colorectal surgery. A cohort study (2008-2019)

Background: Colorectal surgery is associated with the highest rate of surgical site infection (SSI). This study analyses the effectiveness of an interventional surveillance program on SSI rates after elective colorectal surgery.

Material and methods: Cohort study showing temporal trends of SSI rates and Standardized Infection Ratio (SIR) in elective colorectal surgery over a 12-year period. Prospectively collected data of a national SSI surveillance program was analysed and the effect of specific interventions was evaluated. Patient and procedure characteristics, as well as SIR and SSI rates were stratified by risk categories and type of SSI analysed using stepwise multivariate logistic regression models.

Results: In a cohort of 42,330 operations, overall cumulative SSI incidence was 16.31%, and organ-space SSI (O/S-SSI) was 8.59%. There was a 61.63% relative decrease in SSI rates (rho = -0.95804). The intervention which achieved the greatest SSI reduction was a bundle of 6 measures. SSI in pre-bundle period was 19.73% vs. 11.10% in post-bundle period (OR 1.969; IC 95% 1.860-2.085; p < 0.0001). O/S-SSI were 9.08% vs. 6.06%, respectively (OR 1.547; IC 95% 1.433-1.670; p < 0.0001). Median length of stay was 7 days, with a significant decrease over the studied period (rho = -0.98414). Mortality of the series was 1.08%, ranging from 0.35% to 2.0%, but a highly significant decrease was observed (rho = -0.67133).

Conclusions: Detailed analysis of risk factors and postoperative infection in colorectal surgery allows strategies for reducing SSI incidence to be designed. An interventional surveillance program has been effective in decreasing SIR and SSI rates.