Scoring system to predict the risk of surgical-site infection after colorectal resection2

Abstract

Abstract Background There is no dedicated scoring system for predicting the risk of surgical-site infection (SSI) after resection of the colon or rectum. Generic scores, such as the National Nosocomial Infections Surveillance index, are not used by colorectal surgeons. Methods Multivariable analysis of risk factors for SSI was performed in patients who underwent resection of the colon or rectum, and were followed during the first month after operation. A logistic regression model was used to identify determinant variables and construct a predictive score. Results There were 534 patients of whom 114 (21·3 per cent) developed SSI. In multivariable analysis, four parameters correlated with an increased risk of SSI: obesity (odds ratio (OR) 2·93, 95 per cent confidence interval 1·71 to 5·03), contamination class 3–4 (OR 3·33, 2·08 to 5·32), American Society of Anesthesiologists grade III–IV (OR 1·82, 1·14 to 2·90) and open surgery (OR 2·22, 1·01 to 4·88). Each of these contributed 1 point to the risk score. The observed risk of SSI was 5 per cent for a score of 0, 12·0 per cent for a score of 1 point, 18·7 per cent for 2 points, 44 per cent for 3 points and 68 per cent for 4 points. The area under the receiver operating characteristic curve for the score was 0·729. Conclusion A simple clinical score based on four preoperative variables was clinically useful in predicting the risk of SSI in patients undergoing colorectal surgery.