The Utility of Pediatric Appendicitis Risk Calculator (pARC) in Reducing Unnecessary Radiation Exposure in Children with Abdominal Pain in the Emergency Department

From the 2021 HVPAA National Conference

Shreshtha Banga (Brookdale Hospital Medical Center), Mane Sargsyan, Kusum Viswanathan, Fernanda Kupferman


The Pediatric Appendicitis Risk Calculator (pARC) is a novel tool for risk scoring of appendicitis, utilizing the continuous nature of its clinical predictors, with clinically actionable pathways making it more sensitive than older scores. It was developed with the aim to reduce the use of CT scans and outperformed the previously established Pediatric Appendicitis Score (PAS) in predicting the severity of appendicitis. We aim to assess the performance of pARC in the Emergency Department (ED) of an underserved community with a population different from the original study population.


1.The applicability of pARC in a community Emergency Department for risk stratification of appendicitis.
2. To assess if the pARC could be safely used to avoid unnecessary ionizing radiation by decreasing the need for CT scans.
3. To assess the sensitivity, specificity, the positive and negative predictive value of the pARC in a predominantly African American underserved population.


A retrospective data review of records from January 2013 to December 2020 was conducted for all children aged 5-21 years with acute abdominal pain who were evaluated for suspected appendicitis in the Pediatric ED. Children with previous abdominal surgery, inflammatory bowel disease, chronic pancreatitis, Sickle cell anemia, Cystic fibrosis, abdominal trauma in the past 7 days, and pregnancy were excluded. pARC was utilized to compute a score for each patient and correlated with the patient’s CT scan and biopsy results. An analysis was performed to assess the sensitivity of the score in accurately predicting the risk of appendicitis and the performance of the score.


We analyzed 238 patients with suspected appendicitis with a mean age of 12.7 years. Appendicitis was confirmed in 16.8 % of patients. Table 1 summarizes the patient characteristics. The missing data were considered negative. Figure 2 shows the retrospective computation of pARC to classify patients at first contact; 58.8% had low risk, 23.5 % had intermediate-risk, and 1.7 % high risk. In the ultra-low risk category, 2.2% of patients had appendicitis. Figure 3 illustrates the number of CT scans performed and appendicitis in each risk group. The sensitivity of pARC in our study was 70%, specificity of 92%, and NPV of 94%. pARC showed a high degree of discrimination with an AUC of 0.85 and successfully categorized 65% of patients into non-equivocal categories (low risk and high risk). A total of 142 patients (58.8%) in the low-risk and high-risk category underwent CT scans, which may have been avoided upon the use of pARC.


pARC (pediatric Appendicitis Risk Calculator) accurately classifies patients into risk categories, decreasing the need for CT scans for diagnosis of appendicitis

Clinical Implications

The incorporation of pARC in standard practice in Pediatric EDs has the potential to reduce the need for imaging, in effect reducing radiation exposure. Further studies are needed to assess its effect on length of hospital stay and cost reduction.