Comparison of the Appendicitis Inflammatory Response (AIR) and Pediatric Appendicitis Score (PAS) in Predicting Perforated Appendicitis in Children: A Prospective Study

Purpose: Various scoring systems have been developed to facilitate early detection of perforated appendicitis (PA), a serious complication of acute appendicitis (AA), which remains one of the most common surgical emergencies in children. Early identification is essential to minimize morbidity. This study compared the diagnostic performance of the Pediatric Appendicitis Score (PAS) and the Appendicitis Inflammatory Response (AIR) score in distinguishing PA. Materials and Methods: This prospective study included 138 patients aged 3 to 18 years who presented with a preliminary diagnosis of AA between April 2023 and February 2024. Laboratory parameters, including white blood cell count, neutrophil percentage, and C-reactive protein levels, were recorded alongside ultrasonography and computed tomography findings. PAS and AIR scores were calculated for each patient. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) curve analysis to determine the area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Agreement between the two scoring systems in identifying PA was assessed using the kappa statistic. Results: Of the included patients, 68.1% were male, with a mean age of 11.2 ± 3.3 years. PA was confirmed in 16.8% of cases. The prevalence of PA was 59.1% in the high-risk AIR group (scores 9–12) and 29.6% in the AA group (p = 0.029). ROC analysis revealed an AUC of 0.642 for the AIR score at a cut-off > 8.5, with a sensitivity of 59.1%, specificity of 70.4%, PPV of 28.9%, and NPV of 89.4%. The PAS yielded an AUC of 0.673 at a cut-off > 6.5, with a sensitivity of 86.4%, specificity of 38.9%, PPV of 22.4%, and NPV of 93.3%. The agreement between AIR and PAS scores in predicting PA was not statistically significant (kappa p = 0.067). Conclusion: The AIR score demonstrated superior specificity and diagnostic accuracy compared to the PAS in identifying PA.