Computer-aided surveillance of surgical infections and identification of risk factors.

A continuous record of postoperative surgical infections was carried out by electronic data processing (EDP) of 4340 orthopaedic and general operations. The overall infection rate was 6.3%, ranging from 2.3% (clean wounds) to 27.1% (dirty wounds). The corresponding deep infection rates were 1.6%, 0.4% and 4.6%. Employing a multiple logistic regression analysis, 10 risk factors were evaluated. Factors found to be significant were: wound contamination, department, duration of operation, date of operation and age, and in addition for the department of general surgery: surgeon, planning of operation, length of preoperative stay and anatomic groups. A statistical model for identification of risk patients is described. Postoperative stay was on average 20.5 days longer in infected patients. We find that EDP-recording may result in an annual cost reduction of at least 175,000 pounds for our hospital.