Economic Analysis of Diagnostic Imaging in Pediatric Patients With Suspected Appendicitis.

Objective: The use of computed tomography (CT) and ultrasound (US) in patients with acute abdominal pain has substantial variation across pediatric emergency departments (EDs). This study compares the cost of diagnosing and treating suspected appendicitis across a multicenter network of children's hospitals.

Methods: This study is a secondary analysis using deidentified data of a prospective, observational study of patients with suspected appendicitis at nine pediatric EDs. The study included patients 3 to 18 years old who presented to the ED with acute abdominal pain of <96 hours' duration.

Results: Our data set contained 2,300 cases across nine sites. There was an appendicitis rate of 31.8% and perforation rate of 25.7%. Sites correctly diagnosed appendicitis in over 95% of cases. The negative appendicitis rate ranged from 2.5% to 4.7% while the missed appendicitis rate ranged from 0.3% to 1.1% with no significant differences in these rates across site. Across sites, we found a strong positive correlation (0.95) between CT rate and total cost per case and a strong negative correlation (-0.71) between US rate and cost. The cost per case at US sites was 5.2% ($367) less than at CT sites (p < 0.001). Similarly, costs per case at mixed sites were 3.4% ($244) less than at CT sites (p < 0.001). Comparing costs among CT sites or among US sites, the cost per case generally increased as the images per case increased among both CT sites and US sites, but the costs were universally higher at CT sites.

Conclusions: Our results provide support for US as the primary imaging modality for appendicitis. Sites that preferentially utilized US had lower costs per case than sites that primarily used CT. Imaging rates across sites varied due to practice patterns and resulted in a significant cost consequence without higher rates for negative appendectomies or missed appendicitis cases.