Monitoring the occurrence of wound infections after cardiac surgery

The aim of this study was to demonstrate the use of a graphical method for real-time monitoring of the occurrence of surgical wound infection following cardiac surgery. This included developing and incorporating a risk scoring system so that variations in case-mix could be duly accounted for in the monitoring process. We analysed routinely collected data from a London teaching hospital. These data consisted of records for 2146 patients who had undergone cardiac surgery between April 2000 and March 2004 and whose surgical wounds were followed up as part of the local surveillance programme. The risk model was developed using logistic regression analysis with surgical wound infection diagnosed before hospital discharge as the outcome measure. Factors included in the model were the number of surgical wounds, patient age, operations that combined bypass surgery and valve replacement, renal disease and the number of days between hospital admission and surgery. The model was a good predictor of outcomes recorded within an independent data set (Chi-squared=3.81, P=0.58) and we incorporated it into a graphical tool for monitoring outcomes. The risk model and the associated graphical monitoring method could be valuable tools to assist with infection management. If used in real-time, problems with the care process can be quickly identified allowing timely remedial action to be taken.