Risk stratification of surgical site infection in a Tertiary Care Hospital: A prospective case-control study

Introduction: Health care associated infections are preventable cause of morbidity and mortality in healthcare setting. Surgical site infections are no different. It is essential to identify patients who are at high risk of getting SSI and preventive measures instituted even prior to admission for surgery Methods: This study comprising of all the SSIs that we encountered over two years and about 10 to 12 patients (per infected patient) without infection as 'controls'. These two sets of data was used to identify the weightage of each risk factor using logistic regression. Results: We encountered thirty infections during the years 2015 and 2016, three hundred thirty non infected cases were used as control to arrive the weightage of each factor. Using a backward stepwise multivariate logistic regression model in the whole cohort, body mass index > 30 kg/m2, duration of preoperative stay and use of preoperative antiseptic shower were found to be independent predictors for SSIs. We could predict incidence of SSI with good discrimination (area under ROC curve – 0.855, 95% confidence intervals 0.81-0.89). Three factors appear to stand out in our study, they are BMI, preoperative stay and preoperative antiseptic shower. These factors appeared to weigh differently in each specialty. Conclusion: The authors are now able assign scores to each of their patients depending on the type of surgery, sex of the patient, body mass index, number of preoperative days in the hospital, and whether chlorhexidine shower was given or not.