The International Classification of Disease Critical Care Severity Score demonstrates that pediatric burden of injury is similar to that of adults: Validation using the National Trauma Databank

•The International Classification of Disease Critical Care Severity Score (ICASS) is a resource-based severity of injury metric.•ICASS, scored on a 0–100 point scale, is highly predictive of actual critical care utilization.•ICASS can be calculated from existing administrative data, without requiring a trauma registry.•ICASS captures burden of injury in children more fully than existing mortality-based metrics.•Resource-based metrics can help evaluate triage tools in regional pediatric trauma systems. Resource-based severity of injury (SOI) measures, such as the International Classification of Disease (ICD) Critical Care Severity Score (ICASS), may characterize traumatic burden better than standard mortality-based measures. The purpose of this study was to validate the ICASS in a representative national-level trauma cohort and compare SOI measures between children and adults. The National Trauma Databank was used to derive (2008–12) and validate (2013–15) ICASS and ICD Injury Severity Scores (ICISS, standard mortality-based SOI measure). SOI metrics and outcomes were compared between pediatric, adult, and elderly age groups. Logistic regression modeling evaluated predictors of critical care resource utilization. Derivation and validation cohorts consisted of 3.90 and 1.97 million patients, respectively. ICASS strongly predicted actual critical care utilization (OR 1.04, 95% CI 1.04–1.04, p