Abstract 
Background Radiation exposure, transition delays and costs associated with unnecessary imaging in children have stimulated research into clinical decision rules and other interventions to reduce imaging in the emergency department (ED). The objective of this systematic review is to examine the effectiveness of implementing interventions to reduce imaging in children with upper/lower extremity injuries in the ED.
Methods Seven databases and the grey literature were searched up to May 2024. Comparative studies assessing interventions to reduce imaging in children with upper/lower extremity injuries implemented in the ED were eligible. Two independent reviewers screened for study eligibility, quality assessment and data extraction, with disagreements settled via third-party adjudication. Changes in imaging are reported as ORs with 95% CIs, using a random effects model.
Results From 9387 citations, eight unique studies enrolling 7793 children were included with the majority using a before–after design. Potential concerns for bias were documented due to a lack of reporting of key quality domains. Decision rules for ankle injuries successfully reduced radiography (OR=0.11; 95% CI 0.07 to 0.16, I2=38%). A decision rule for wrist injuries reduced imaging (OR=0.06; 95% CI 0.03 to 0.11); however, eight injuries were missed. Two studies implementing clinical guidelines reported decreases in radiographs per patient (p<0.001). One trial reported increased imaging in children assessed by triage nurses using an established clinical decision rule (OR=5.44; 95% CI 2.96 to 10.02), with 16 missed injuries identified.
Conclusions Guidelines incorporating clinical decision rules, particularly decision rules for ankle injuries, can reduce radiography for children with extremity injuries in the ED. Further investigations are warranted to identify other extremity injuries, the components of the intervention and the most efficient clinicians to target.
