Undertriage of Pediatric Major Trauma at a Spanish Pediatric Trauma Center: A 10-Year Retrospective Cohort Study

Background: Accurate field triage is a cornerstone of an inclusive trauma system, but pediatric undertriage remains poorly characterized outside North America. We aimed to estimate the rate of major trauma undertriage in a Spanish pediatric trauma center, to identify patient factors associated with it, and to explore its relationship with early clinical outcomes. Methods: Retrospective cohort study (2016–2025) of children aged 0–14 years admitted to the pediatric intensive care unit (PICU) of the reference pediatric trauma center for the province of Granada, Spain. Major trauma was defined using a composite of the Cribari Matrix (ISS > 15) and/or the Need for Trauma Intervention (NFTI) criteria. Undertriage was defined as delayed (>2 h) or non-direct transport to the trauma center despite proximity (<30 min). The primary outcomes were the undertriage rate and the patient factors associated with it, examined by bivariate analysis and by Firth-penalized logistic regression with intercept correction (FLIC). Clinical outcomes (Glasgow Outcome Scale, PICU and total hospital length of stay) were prespecified as exploratory and analyzed with generalized linear models—binomial for binary outcomes and negative binomial for counts—and, as a sensitivity analysis, with targeted maximum likelihood estimation (TMLE). Results: Out of 1716 PICU admissions during the study period, 157 (9.1%) were due to injury, 131 (7.6%) were eligible traumatic injuries and 94 (5.5%) children met major trauma criteria (median age 8.0 years; 73.4% male; 78.7% blunt trauma; and median ISS 18.5). The undertriage rate was 23.4% (22/94; 95% CI 15.3–33.3). No patient characteristic differed significantly between undertriaged and correctly triaged children. Undertriaged children tended to be older (median 11.0 vs. 7.0 years; p = 0.117), and the overall association between age category and undertriage did not reach significance in the FLIC model (p = 0.069). One child (1.1%) died in PICU and 75 (79.8%) achieved a good functional recovery (Glasgow Outcome Scale 5). Undertriage was not associated with functional outcome, PICU length of stay or total hospital length of stay in either unadjusted or adjusted analyses. Conclusions: Nearly one in four children with major trauma who reached this pediatric trauma center met the predefined criteria for undertriage. This rate should be interpreted as undertriage conditional on arrival at the Pediatric Trauma Center and not as a system-level or provincial estimate. Multicenter prospective studies using standardized definitions and incorporating prehospital transport data are needed to better characterize the population-level burden and clinical impact of pediatric undertriage.