Leveraging a nationwide infection surveillance program to implement a colorectal surgical site infection reduction bundle: a pragmatic, prospective and multicentre cohort study

Background: Bundled interventions usually reduce surgical site infection (SSI) when implemented at single hospitals, but the feasibility of their implementation at nationwide level and their clinical results are not well established. Materials and methods: Pragmatic interventional study to analyse the implementation and outcomes of a colorectal surgery care bundle within a nationwide quality improvement program. The bundle consisted of: antibiotic prophylaxis, oral antibiotic prophylaxis (OAP), mechanical bowel preparation (MBP), laparoscopy, normothermia, and a wound retractor. Control (CG) and Intervention (IG) groups were compared. Overall SSI, superficial (S-SSI), deep (D-SSI) and organ/space (O/S-SSI) rates were analysed. Secondary endpoints included microbiology, 30-day mortality and hospital stay (LOS). Results: A total of 37,849 procedures were included, 19,655 in the CG and 18,194 in the IG. In all, 5,462 SSIs (14.43%) were detected: 1,767 S-SSI (4.67%), 847 D-SSI (2.24%) and 2,838 O/S-SSI (7.5%). Overall SSI fell from 18.38% (CG) to 10.17% (IG), OR 0.503, [0.473-0.524]. O/S-SSI rates were 9.15% (CG) and 5.72% (IG), OR 0.602, [0.556-0.652]. The overall SSI rate was 16.71% when no measure was applied and 6.23% when all six were used. Bundle implementation reduced the probability of overall SSI (OR 0.331; CI95 0.242, 0.453), and also O/S-SSI rate (OR 0.643; CI95 0.416, 0.919). In the univariate analysis, all measures except normothermia were associated with a reduction in overall SSI, while only laparoscopy, OAP, and MBP were related with a decrease in O/S-SSI. Laparoscopy, wound retractor and OAP decreased overall SSI and O/S-SSI in the multivariate analysis. Conclusions: In this cohort study, the application of a specific care bundle within a nationwide nosocomial infection surveillance system proved feasible, and resulted in a significant reduction in overall and O/S-SSI rates in elective colon and rectal surgery. The OR for SSI fell between 1.5 and 3 times after the implementation of the bundle