Despite improved surgical techniques there is still a risk of mortality in elective general surgery.

In a prospective study preoperative data from 3250 patients were collected and compared with postoperative systemic complications, using univariate khi2 analysis.

Highly significant (P<0.00001) variables were subjected to stepwise logistic regression analysis.

The severity of operative procedure, higher American Society of Anesthesiologists (ASA) grade, symptoms of respiratory disease and malignancy were found to be significant risk factors predicting postoperative morbidity (P<0.05).

Using these four variables, a simple preoperative risk scoring system has been defined.

Class A (up to 5 points) was defined as a low-risk group (systemic complication rate 5.0 per cent), class B (5-7 points) was intermediate risk (systemic complication rate 17.9 per cent) and class C (8-10 points) was high risk (systemic complication rate 33.3 per cent).

Patients at high risk for perioperative and postoperative complications are more likely to be identified by this analysis than by using the ASA classification alone.