Surgical audit using the POSSUM scoring tool in vascular surgery patients

Abstract

Introduction

Currently, crude morbidity and mortality rates are used to assess vascular surgical outcome. However, as a high-risk specialty, this may not be representative of quality of care.

Aim

We evaluated the POSSUM score as a measure of performance in our vascular unit, and also its usefulness on an individual patient basis for predicting outcome.

Patients and methods

A total of 106 patients were prospectively scored using the vascular-POSSUM score, and mean predicted and observed morbidity and mortality were compared with one-sample t tests.

Results

Receiver operator characteristic curves were used to determine if POSSUM scores were associated with the end-points of morbidity and mortality. Predicted and observed morbidity (41 and 35.8%, respectively) were not significantly different (P = 0.066). POSSUM did, however, over-predict mortality at 9.7% compared to the observed mortality of 5.7% (P = 0.021). While the discrimination for predicting morbidity was poor, POSSUM scores were significantly associated with mortality end-points (area under ROC curve = 0.97250). POSSUM morbidity scores closely correlate with observed outcomes.

Conclusion

Although POSSUM did over-predict mortality, high mortality scores may be useful for identifying patients at particularly high risk post-operatively. The POSSUM score is a useful adjunct to interpretation of morbidity and mortality statistics, and we would recommend its wider implementation for surgical audit.