Association between hospital volume and in-hospital mortality in pediatric severe traumatic brain injury: a nationwide retrospective observational study in Japan.

The objective of this study was to investigate the association between hospital volume and in-hospital mortality in pediatric patients with severe traumatic brain injury (TBI). This retrospective cohort study used data from the Japan Trauma Data Bank between 2010 and 2018, specifically those of pediatric patients with severe TBI (Glasgow Coma Scale [GCS] score < 9 and head Abbreviated Injury Scale score > 2). Hospital volume was defined as the number of pediatric patients with severe TBI throughout the study period. Hospital volume was categorized as low (reference category: 1-9 patients), middle (10-17 patients), or high (> 18 patients) volume. Multivariate mixed-effects logistic regression analysis was performed to determine the association between hospital volume categories and in-hospital mortality. Subgroup analyses were performed using data on craniotomy and the presence of severe torso injuries. In the sensitivity analyses, patients with a GCS score of 3, interhospital transfer, and major intensive care unit complications were excluded. A total of 1148 pediatric patients with severe TBI, with a median age of 12 years (IQR 7-16 years), treated at 141 hospitals were included. In total, 236 patients (20.6%) died in the hospital. Multivariate analysis showed no significant association between hospital volume and in-hospital mortality (high volume: OR 1.15, 95% CI 0.80-1.64; middle volume: OR 0.89, 95% CI 0.62-1.26). Subgroup and sensitivity analyses showed similar results. Hospital volume may not be associated with in-hospital mortality in pediatric patients with severe TBI.