Hospital type predicts computed tomography use for pediatric appendicitis

Background: Evidence-based guidelines recommend ultrasound (US) over computed tomography (CT) as the primary imaging modality for suspected pediatric appendicitis. Continued high rates of CT use may result in significant unnecessary radiation exposure in children. The purpose of this study was to evaluate variables associated with preoperative CT use in pediatric appendectomy patients. Methods: A retrospective cohort study of pediatric patients who underwent appendectomy for acute appendicitis in 2015-2016 at National Surgical Quality Improvement Program for Pediatrics (NSQIP-P) hospitals was conducted. Pediatric (>18 years old) patients who underwent appendectomy for acute appendicitis in an NSQIP-P hospital from 2015 to 2016 were included. Patients were excluded if they underwent interval or incidental appendectomy or did not have a final diagnosis of appendicitis. Variables associated with imaging evaluation, including age, body mass index (BMI), race/ethnicity, gender and hospital of presentation (NSQIP-P vs. non-NSQIP-P hospital) were evaluated. The primary outcome was receipt of preoperative CT. Secondary outcomes include reimaging practices and trends over time. Results: 22,333 children underwent appendectomies, of which almost all were imaged preoperatively (96.5%) and 36% of whom presented initially to a non-NSQIP-P hospital. Overall, US only was the most common imaging modality (52%), followed by CT only (27%), US+ CT (16%), no imaging (3%), MRI+/- CT/US (1%) and MRI only (<1%). On regression, older age (>11 years), obesity (BMI >95th percentile for age), and female gender were associated with increased odds of receiving a CT scan. However, initial presentation to a non-NSQIP-P hospital was the strongest predictor of CT use (OR 9.4, 95% CI 8.1-10.8). Reimaging after transfer was common, especially after US and MRI at a non-NSQIP-P hospital. CT use decreased between 2015 and 2016 in non-NSQIP-P hospitals but remained the same (25%) in NSQIP-P facilities. Conclusions: Though patient characteristics were associated with different imaging practices, presentation at a referral, nonchildren's hospital is the strongest predictor of CT use in children with appendicitis. NSQIP-P hospitals frequently reimage transferred patients and have not reduced their CT use. Novel strategies are required for all hospital types in order to sustain reduction in CT use and mitigate unnecessary imaging. Level of Evidence: Level III. Type of Study: Retrospective comparative study. (c) 2018 Elsevier Inc. All rights reserved.