Abstract
BACKGROUND: Acute Appendicitis (AA) is the most common abdominal surgical emergency. It requires proper management to decrease mortality and morbidity. Clinical scoring systems for diagnosing AA aimed to decrease the use of radiological scans and the rate of negative appendectomies (NA). We aim to assess the adult appendicitis score (AAS) in the diagnosis prediction of AA. METHOD: A retrospective study with 1303 cases of AA is performed. We compared the correlation of AAS and Alvarado scores to postoperative histopathology. Specificity, sensitivity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) were assessed. ROC was used. RESULTS: AAS risk stratification was applied to the study population. Group I for a low probability, and groups II and III for an intermediate and high probability of AA. We found that 159 patients were matched in group I, 505, and 639 were in groups II and III of AAS, respectively. The correlation between Alvarado and AAS with HP was significant. AAS ≥ 16 presented sensitivity and specificity of 50 % and 75.47 %, respectively, with PPV of 97.96 % and NPV of 6.02 %, with an accuracy of 51.04 %. Regarding AAS ≥ 11, the sensitivity was 88.96 %, specificity was 39.62 %, PPV was 97.2 %, NPV was 13.21 %, and accuracy was 86.95 %. CONCLUSION: AAS is relatively more accurate than Alvarado's score, especially in selecting a safe candidate for discharge from an emergency. In addition, AAS is found to decrease the need for radiological images and NA rate more than Alvarado.