Low-Value Diagnostic Imaging Use in the Pediatric Emergency Department in the United States and Canada

Importance Diagnostic imaging overuse in children evaluated in emergency departments (EDs) is a potential target for reducing low-value care. Variation in practice patterns across Canada and the United States stemming from organization of care, payment structures, and medicolegal environments may lead to differences in imaging overuse between countries. Objective To compare overall and low-value use of diagnostic imaging across pediatric ED visits in Ontario, Canada, and the United States. Design, Setting, and Participants This study used administrative health databases from 4 pediatric EDs in Ontario and 26 in the United States in calendar years 2006 through 2016. Individuals 18 years and younger who were discharged from the ED, including after visits for diagnoses in which imaging is not routinely recommended (eg, asthma, bronchiolitis, abdominal pain, constipation, concussion, febrile convulsion, seizure, and headache) were included. Data analysis occurred from April 2018 to October 2018. Exposures Diagnostic imaging use. Main Outcome and Measures Overall and condition-specific low-value imaging use. Three-day and 7-day rates of hospital admission and those admissions resulting in intensive care, surgery, or in-hospital mortality were assessed as balancing measures. Results A total of 1 783 752 visits in Ontario and 21 807 332 visits in the United States were analyzed. Compared with visits in the United States, those in Canada had lower overall use of head computed tomography (Canada, 22 942 [1.3%] vs the United States, 753 270 [3.5%]; P P P P Conclusions and Relevance Low-value imaging rates were lower in pediatric EDs in Ontario compared with the United States, particularly those involving ionizing radiation. Lower use of imaging in Canada was not associated with higher rates of adverse outcomes, suggesting that usage may be safely reduced in the United States.