SP 10.05 Use of the Appendistat (APS) Score to Triage Patients with Suspected Acute Appendicitis: A Retrospective Cross-Sectional Study in One of The Busiest UK Surgical Emergency Units
Mohammad Eddama, Thomas Parry-Jones, George Kostopoulos, Geoffrey Roberts, Richard C Cohen, Giles Bond-SmithAbstract
Introduction
Although non-operative management of acute appendicitis may be appropriate in selected cases, appendicectomy remains the gold standard treatment. Early prioritisation of patients at risk of developing complicated appendicitis is important for optimising outcomes. This study aims to assess the predictive value and clinical utility of the appendistat scoring (APS) as a triage tool to identify patients at increased risk of complicated appendicitis.
Methods
This retrospective, cross-sectional observational study included 592 patients who underwent appendicectomy. Based on their final histological diagnosis, patients were categorised as normal, acute uncomplicated (AUA), or acute complicated appendicitis (ACA). The discriminative performance of the APS score for identifying ACA at presentation was evaluated.
Results
APS scores were significantly higher in patients with ACA (median=63%, range=2%–97%) compared with a combined comparator group of normal appendix and AUA (median=40%; range=1%-100%; p<0.0001). In this pragmatic clinical comparison, the APS score demonstrated moderate discriminative performance, with an area under the receiver operating characteristic curve (AUC) of 0.71 (95% CI=0.65, 0.76). Using a predefined APS score cut-off value of 40%, sensitivity for identifying patients with ACA was 79% (95% CI=71%, 85%); specificity was 51% (95% CI=64%, 56%); and positive and negative predictive values were 35% and 83%, respectively.
Conclusion
The APS score is a safe and readily available triage tool that supports early risk stratification in patients presenting with acute appendicitis. An APS cut-off of 40% identifies patients at risk of complicated appendicitis and may assist in prioritising urgent surgical intervention when used alongside clinical assessment.