Mortality and Case Fatality Rates Associated With Surgical Site Infections: A Retrospective Surveillance Study.

Background: Surgical site infections (SSIs) have been associated with increases in terms of costs, hospital stay, morbidity, and mortality. We aimed to assess trends in SSIs monitored through 10 years of surveillance activities in our region, and to describe mortality attributable to SSIs in the two most frequently monitored surgical procedures: colorectal surgery and hip arthroplasty. Methods: A retrospective cohort study was conducted among the 42 hospitals participating in the surveillance network of our region in northern Italy. All colorectal and hip arthroplasty procedures performed between January 1st, 2010, and December 31st, 2019, and monitored through the surveillance system were included in the study. Surgical site infection rates, overall mortality, case fatality rates (CFR), and mortality attributable to SSIs were evaluated overall and by year of participation in the surveillance program. Results: In total, 11,417 colon surgery and 20,804 hip arthroplasty procedures were included. Among colon surgery procedures, SSI rates decreased from 9.21% in 2010 to 5.7% in 2019. A significant decreasing trend was found for overall mortality (p = 0.008), which progressively decreased from 4.96% in 2010 to 2.96% in 2019. Among hip arthroplasty procedures, no significant trend emerged for SSI and mortality rates. Considering the 10-year period, the CFR was 6.62% and 3.7% for SSIs after colon surgery and hip arthroplasty procedures, respectively. Conclusions: The impact of SSIs on the clinical outcomes of patients undergoing surgery highlights the importance of SSI surveillance.