Trends in mortality associated with surgical site infections: a cohort study in Italy, 2009-2019

Abstract

Surveillance programs have proven to be effective in reducing surgical site infection (SSI) rates. In 2008 Piedmont joined the Italian national surveillance system. The aim of this study was to evaluate mortality rates and trends associated with SSIs in Piedmont from 2009 to 2019 for the two most frequently performed surgical procedures, hip arthroplasty (HPRO) and colon surgery (COLO).Data were collected through the national surveillance system, which includes 42 hospitals in Piedmont who participated in the surveillance program from 2009 to 2019. Procedure-specific SSI rates, overall mortality rates and case fatality rates (CFR) associated with SSIs were calculated, overall and per year. Trends were evaluated using the chi-squared test for trends. Analyses were performed using Epi Info v. 7.2.A total of 33438 surgical procedures (21645 HPRO, 11793 COLO) were monitored over the study period from the hospitals participating in the network. 1215 SSIs (293 HPRO, 922 COLO) were observed and 617 deaths were registered (222 HPRO, 395 COLO). For HPRO procedures, an overall SSI rate of 1.35% was found, with an overall mortality of 1.03% and a CFR of 3.75%. No significant trend was observed. Considering COLO interventions, an overall SSI rate of 7.82% was found, with an overall mortality of 3.35% and a CFR of 6.94%. There was a statistically significant downward trend in SSI and overall mortality rates (p = 0.046 and 0.005, respectively).Considering HPRO, it is possible that the lack of significant trends could be due to the already low SSI and overall mortality rates, with the protective effect of surveillance having reached a plateau. Regarding COLO procedures, a significant reduction in SSI and overall mortality rates was observed during the study period. The reduction in mortality could be due to the decrease in SSI rates, however other factors not analysed in our study could have contributed.• This study brings further evidence to the protective effect of surveillance, attributable to an improvement in healthcare quality and patients’ safety.• A significant decrease in COLO mortality rates was observed, which could be due to the decreasing trend in SSI rates.