Risk factor identification and contribution to surgery-specific surgical site infection

Background: To identify common risk factors for the future occurrence of SSI across digestive system surgical procedures, thoracic surgery and orthopaedic procedures and quantify what the marginal contribution of explaining the future occurrence of SSI is of risk factors specific to each group of surgeries. Methods: Retrospective data from serial point-prevalence studies, performed at the Erasmus MC University Medical Center, Rotterdam, The Netherlands were used, together with medical data, from 3.250 surgical procedures, during the period January 2013 to 29 June 2014. Common risk factors across three groups of surgical procedures were identified by scanning literature and univariate analysis. A multivariate forward-step logistic regression model was used to identify the marginal contribution of the risk factor specific to each group of surgical procedure using the increase in the Gini coefficient. Results: For digestive system surgical procedures, antibiotic use, temperature, smoking status, age, CRP, thrombocyte, during of surgery and surgical urgency are risk factors for SSI, where the last four were specific to the digestive system group of surgical procedures and increased the Gini coefficient by 9.5% (0.63 to 0.69). Preoperative length of stay, antibiotic use and Leukocyte are risk factors for orthopaedic surgical procedures. Temperature, age and the use of antibiotics were significant for thoracic surgical procedures. Conclusion: ASA class, body mass index (BMI), Preoperative length of stay, diabetes, antibiotic use, age, Leukocyte, temperature and smoking status as general risk factors common to digestive, orthopaedic and thoracic surgical procedures using existing literature and univariate logistic regression. Risk factors for SSI, specific to a surgical procedure group can increase the ability to explain the future occurrence of SSI by 9.5%. The models developed in this study can aid healthcare workers to improve preoperative counselling and help identify potentially modifiable risk factors.