Surgical audit using the POSSUM scoring tool in vascular surgery patients.
BACKGROUND
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.


OBJECTIVE
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.


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 endpoints (area under ROC curve = 0.97250). POSSUM morbidity scores closely correlate with observed outcomes.


CONCLUSIONS
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.
Byrne
J S
JS
Department of Vascular Surgery, St Vincent’s Hospital, Dublin, Ireland. jbyrne2@rcsi.ie
Condon
E T
ET
Ahmed
M
M
Conroy
R
R
Mehigan
D
D
Sheehan
S J
SJ
Barry
M C
MC
D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit / Q000379:methods*; D008875:Middle Aged; D009017:Morbidity; D017063:Outcome Assessment, Health Care / Q000379:methods*; D012372:ROC Curve; D014656:Vascular Surgical Procedures / Q000401:mortality* / Q000592:standards*