Association between the introduction of a national targeted intervention program and the incidence of surgical site infections in Swiss acute care hospitals

Abstract

Background: In Switzerland, the national surgical site infection (SSI) surveillance program showed a modest decrease in SSI rates for different procedures over the last decade. The study aimed to determine whether a multimodal, targeted intervention program in addition to existing SSI surveillance is associated with decreased SSI rates in the participating hospitals.

Methods: Prospective multicenter pre- and postintervention study conducted in eight Swiss acute care hospitals between 2013 and 2020. All consecutive patients > 18 years undergoing cardiac, colon, or hip/knee replacement surgery were included. The follow-up period was 30 days and one year for implant-related surgery. Patients with at least one follow-up were included. The intervention was to optimize three elements of preoperative management: (i) hair removal; (ii) skin disinfection; and (iii) perioperative antimicrobial prophylaxis. We compared SSI incidence rates (main outcome measure) pre- and postintervention (three years each) adjusted for potential confounders. Poisson generalized linear mixed models fitted to quarter-yearly confirmed SSIs and adjusted for baseline differences between hospitals and procedures. Adherence was routinely monitored through on-site visits.

Results: A total of 10 151 patients were included, with a similar median age pre- and postintervention (69.6 and IQR 60.9, 76.8 years, vs 69.5 and IQR 60.4, 76.8 years, respectively; P = 0.55) and similar proportions of females (44.8% vs. 46.1%, respectively; P = 0.227). Preintervention, 309 SSIs occurred in 5 489 patients (5.6%), compared to 226 infections in 4 662 cases (4.8%, P = 0.09) postintervention. The adjusted incidence rate ratio (aIRR) for overall SSI after intervention implementation was 0.81 (95% CI, 0.68 to 0.96, P = 0.02). For cardiac surgery (n = 2 927), the aIRR of SSI was 0.48 (95% CI, 0.32 to 0.72, P < 0.001). For hip/knee replacement surgery (n = 4 522), the aIRR was 0.88 (95% CI, 0.52 to 1.48, P = 0.63), and for colon surgery (n = 2 702), the aIRR was 0.92 (95% CI, 0.75 to 1.14, P = 0.49).

Conclusions: The SSI intervention bundle was associated with a statistically significant decrease in SSI cases. A significant association was observed for cardiac surgery. Adding a specific intervention program can add value compared to routine surveillance only. Further prevention modules might be necessary for colon and orthopedic surgery.

Keywords: Hair removal; Multimodal intervention bundles; Perioperative antimicrobial prophylaxis; Preoperative management; Skin disinfection; Surgical site infection; Surveillance.

Fig. 1

Quarterly SSI rates over the study period with pointwise 95% CIs (black) with fitted interrupted Poisson generalized linear model (red line) with interruption at time 0 (start of the intervention) and a 3-month wash-out phase. SSIs for a all procedures; b cardiac surgery; c colon surgery; and d knee/hip replacement. SSI, surgical site infection

Fig. 2

Intervention bundle adherence by quarter, from Q1 year 1 to Q4 year 3, after local implementation of the intervention (N = 916 observations). Compliance with each element of preoperative preparation (red = correct hair removal, green = correct skin disinfection, turquoise = correct administration of antibiotic prophylaxis) is shown as a rate with 95% CIs per quarter. In purple, the achievement of the entire bundle (simultaneous fulfilment of all three elements) is shown