External Validation of a Prognostic Model for the Presence of Acute Appendicitis in Children

Abstract

Background: Acute appendicitis is one of the most common and serious urgent pathologies in pediatric surgery. Rapid and accurate diagnosis of this condition is critically important to minimize the risk of complications such as appendix perforation, peritonitis, and sepsis. Despite the ongoing development of modern laboratory and instrumental diagnostic methods, identifying acute appendicitis in pediatric patients remains challenging. The present study aims to confirm the effectiveness and reliability of the developed prognostic model for predicting acute appendicitis in children and to compare its performance with previously established predictive methods. Methods and Results: A new cohort of 101 pediatric patients with a confirmed diagnosis of acute appendicitis and 100 patients with functional gastrointestinal disorders were studied to assess the effectiveness of the developed logistic regression-based nomogram for predicting acute appendicitis in children. The predictive model incorporated clinical and laboratory parameters, including nausea, leukocyte and lymphocyte counts, appendix diameter on ultrasound, patient age, and vomiting. Using ROC curve analysis and confusion matrix assessment, the model's performance was compared to the Alvarado score and pediatric appendicitis score (PAS). The proposed model produced a minimal number of false-positive (14.8%) and false-negative results (9%). The ROC curve analysis confirmed superior diagnostic accuracy. The nomogram demonstrates the highest sensitivity (85.1%) and specificity (91.0%), indicating its superior ability to identify cases of appendicitis. The sensitivity and specificity of PAS were 80.2% and 88.0%, while AS showed 72.3% and 84.0%, respectively. Conclusion: The developed predictive model is a reliable tool for diagnosing acute appendicitis in children, demonstrating higher accuracy than existing scoring systems. Its integration of clinical, laboratory, and ultrasound parameters enhances diagnostic precision and reduces the likelihood of unnecessary surgeries. Further external validation on larger populations is recommended to ensure its broad applicability in clinical practice.

Keywords

• acute appendicitis
• pediatric surgery
• prognostic model
• alvarado score
• pediatric appendicitis score