A quality improvement program to reduce surgical site infections after cardiac surgery: A 10-year cohort study

Objectives: To assess trends in surgical site infection (SSI) incidence in cardiosurgery following a quality improvement initiative in infection prevention and control (IP&C). Methods: This is a historical cohort study encompassing a 10-year surveillance period (2014-2023) in a cardiosurgical department in a multi-organ transplant center. The study encompassed three periods: a baseline period (Phase_1: January 2014-December 2018); an implementation phase covering quality improvement initiatives targeting various aspects of IP&C including organizational factors, pre-operative, intra-operative, post-operative measures, and post-hospitalization care (Phase_2: January 2019-June 2021); a post-implementation phase (Phase_3: July 2021-September 2023). A general linear mixed model was used to assess differences in SSI rates between distinct phases, adjusted for length of hospitalization, American Society of Anaesthesiologists (ASA) physical status classification, and Diagnostic-Related Groups (DRG) weight. The latter two were used as random effects. Results are reported as odds ratios [OR] with 95% confidence interval [CI]. Results: All cardiac surgery patients were included (n = 5851). A total of 208 patients developed SSI (3.5 %). SSI incidence for phase_1, phase_2 and phase_3 were 4.5 %, 4.1 %, and 1.2 %, respectively. The mixed model regression analysis indicated that, compared with the reference period (Phase1), SSI risk did not drop during the implementation phase (OR 0.81, 95 % CI 0.59-1.13, P < 0.001 vs. reference period). A decrease in SSI risk was observed during the post-implementation phase (OR 0.19, 95 % CI 0.11-0.32) CONCLUSIONS: A quality improvement initiative encompassing measurements at all levels potentially impacting SSI risk was implemented over a 2.5 years period. While no risk reduction was observed during the implementation phase, a significant reduction in SSI risk took place in the post-implementation phase. Implications for clinical practice: This study suggests that considerable time may be required to achieve a substantial SSI risk reduction. We assume this may be attributed to the time required to achieve appropriate adherence with IP&C protocols.