RESUMO
AIM: To report on the reduction in the surgical site infection (SSI) rate in the Southern Cross Hospitals network over a 12-year period, 2004-2015, following active surveillance and quality improvement actions. METHODS: Ten hospitals in the network performed prospective SSI surveillance using standard definitions across a range of ten surgical procedure groups. Data was manually collected on a standardised form and entered into a bespoke database. Information collected included timing and dose of surgical antibiotic prophylaxis, type of surgical site skin preparation used, and patient information on smoking, diabetes and body mass index (BMI). Patients were contacted 30 days after their elective surgery to detect SSIs presenting after discharge from hospital. Surveillance results were widely reported to infection control and clinical review committees. Quality improvement activities to increase use of best practice interventions for surgical antibiotic prophylaxis and alcohol-based skin preparations were initiated during the surveillance period. RESULTS: 42,792 procedures performed in ten hospitals were analysed. There were 932 (2.2%) SSIs. The SSI rate decreased from 3.5% in 2004 to 1.2% in 2015, r-0.865, p=<0.0001, a decrease of 59%, approximately 5% a year. Rates decreased in seven of the 10 hospitals, p≤0.02 for each, and in five of the ten procedure groups, p≤0.02 for each. Diabetic patients, odds ratio (OR) 1.4 (95% confidence interval (CI) 1.1-1.9), obese patients (BMI>30), OR 2.0 (95% CI 1.6-2.4), and those with a surgical risk score of ≥1 OR 1.3 (95% CI 1.1-1.6) had higher SSI rates. These three patient risk factors increased during the 12-year period. The use of alcohol-based skin preparations increased during the period from 63% to 84% in the first two and last two years respectively, p<0.0001. Use of an alcohol-based skin preparation was associated with a reduction in SSIs OR 0.54 (95% CI 0.47-0.62). On time prophylaxis improved from 72% to 95% over the 12 years, p<0.0001, and on time prophylaxis was associated with a reduction in SSIs, OR=0.62 (95% CI 0.51-0.75). The use of 2g doses of cefazolin increased significantly after 2010, p<0.0001. The most common cause of SSI was Staphylococcus aureus which was present in 54% of cases with a positive culture. CONCLUSIONS: This long-term surveillance and quality improvement programme has made a significant contribution to the overall reduced rate of SSIs in Southern Cross Hospitals. This reduction occurred despite patient risk factors for SSI increasing. Further reduction is possible with higher adherence to best practice and interventions aimed at reducing S. aureus SSIs.