Diagnostic Decision-Making in Intermediate-Risk Pediatric Appendicitis: A Prospective Cohort Study.

Abstract

Diagnosing acute appendicitis in children with intermediate Pediatric Appendicitis Score (PAS) values remains a major clinical challenge. In this diagnostic gray zone, clinical findings, laboratory markers, and imaging often provide conflicting information, leading to uncertainty and variable management strategies. The aim of this study was to identify predictive factors of true appendicitis in children presenting with suspected appendicitis and intermediate PAS scores. We conducted a prospective observational study including children aged 2-14 years presenting with suspected appendicitis and a PAS of 4-6 at a tertiary referral center between January 2022 and October 2025. Among 559 included children, 289 (51.7%) had true appendicitis. The mean age was 9.4 ± 2.5 years, and males accounted for 58.1% of the cohort. On multivariable analysis, positive ultrasound was the strongest independent predictor of appendicitis (OR 55.1; 95% CI 29.4-103.2; p < 0.001), followed by localized right lower quadrant tenderness (OR 2.98; p = 0.003), white blood cell count > 15 × 10⁹/L (OR 2.53; p = 0.003), and male sex (OR 1.99; p = 0.015). Ultrasound demonstrated excellent diagnostic performance, with a sensitivity of 94%, a negative predictive value of 93%, and an overall accuracy of 88%. In children with intermediate PAS scores, ultrasound plays a central role in diagnostic decision-making. Its strong rule-out value allows meaningful risk reclassification, supporting safe observation while guiding timely surgical intervention when positive.