Comparative Evaluation of Clinical Scoring Systems and Development of a Combined Predictor Score for Acute Appendicitis

Abstract

Background: Acute appendicitis remains a common surgical emergency in which variable clinical presentations can result in diagnostic uncertainty and negative appendectomy. Clinical scoring systems provide structured assessment, but their performance may vary between populations. This study compared six established scoring systems and evaluated a newly formulated combined predictor score in a secondary-care hospital population. Materials and Methods: This cross-sectional observational study included 100 patients older than 12 years presenting with suspected acute appendicitis and scheduled for appendectomy at Victoria Hospital attached to BMC-RI Bengaluru between July 2025 and July 2026. Clinical, laboratory, operative and histopathological data were collected. Alvarado, Modified Alvarado Scoring System, Teicher, Fenyo, Ohmann and RIPASA scores were calculated for each patient. Candidate predictors were assessed using sensitivity, specificity, risk ratio, Yates-corrected Chi-square and P-values. A16-item combined predictor score was formulated by assigning one point to each significant predictor. Diagnostic performance was assessed using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and receiver operating characteristic (ROC) area under the curve (AUC). Results: Sixty-seven patients had acute appendicitis and 33 had a normal appendix. RIPASA and Teicher had the highest sensitivity (97.56% each); Fenyo had the highest specificity (97.78%) and PPV (98.04%); Ohmann had the highest diagnostic accuracy among the established scores (93.70%). The new combined predictor score achieved 95.12% sensitivity, 95.56% specificity, 97.50% PPV, 91.49% NPV, and 95.28% diagnostic accuracy at a cutoff of 10, with ROC AUC 0.99. Serum bilirubin was not significantly associated with appendicular perforation (Yates-corrected c²=0.01788; P = 0.893659). Conclusion: Diagnostic performance varied substantially across scoring systems. In this study population, the new combined predictor score demonstrated the highest overall diagnostic accuracy and a high ROC AUC. Its simple dichotomous structure may be useful in secondary-care settings, although prospective validation in larger and more diverse populations is required before routine clinical adoption.