International Journal of Preventive Medicine (Int J Prev Med)2008-78021432023040527952795ENDepartment of Pediatrics, Hamadan University of Medical Sciences, HamadanDepartment of Pediatrics, Hamadan University of Medical Sciences, HamadanDepartment of Pediatrics, Hamadan University of Medical Sciences, HamadanHamadan University of Medical Sciences, Besat Hospital, HamadanCommunity Medicine, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan & School of Public Health and Research Center for Health Sciences, Hamadan University of Medical Sciences, Hamadan20230405Background: This study aimed at evaluating the accuracy of the pediatric appendicitis scoring method in differentiating nonspecific abdominal pain (NSAP) from appendicitis. Methods: This cross‑sectional study was conducted on 391 children who were hospitalized in the emergency ward due to acute abdominal pain suspected of appendicitis . Pediatric Appendicitis Score (PAS), C-reactive protein (CRP), and appendicitis pathology results of patients undergoing surgery were recorded. Results: The results showed that the no significant difference was found among patients in the three experimental groups (appendicitis, specific abdominal pain except appendicitis, and NSAP) with respect to temperature (p = 0.212), but the other variables were significantly different. Findings showed that high CRP frequency, pain migration to right lower quadrant (RLQ), tenderness in right iliac fossa (RIF), anorexia, leukocytosis, high neutrophil, and mean tenderness in RLQ in the appendicitis group were higher than those in the other two groups (p = 0.001). The PAS questionnaire can also be used as a reliable questionnaire with appropriate sensitivity (0.929) and specificity (0.993), and this questionnaire along with detailed clinical examinations could reduce the rate of negative appendectomy to less than 1%. Conclusions: This study showed high accuracy of PAS in diagnosing children with appendicitis and differentiating appendicitis from cases of NSAP and specific abdominal pain other than appendicitis. The PAS system could also significantly reduce cases of negative appendicitis. Although high CRP had an excellent ability to diagnose appendicitis, its accuracy was lower than PAS.http://ijpm.mui.ac.ir/index.php/ijpm/article/view/2795http://ijpm.mui.ac.ir/index.php/ijpm/article/download/2795/717718635