Spatial and socioeconomic correlates of prehospital whole blood transfusions in violence-related trauma.

Abstract

Prehospital blood product administration is a critical intervention for traumatic hemorrhagic shock. This study evaluates the spatial distribution of prehospital low-titer O whole blood (LTOWB) transfusions for violence-related trauma within a single urban setting by identifying ZIP codes where eligible 911 calls originated and examining associated community-level social determinants. A retrospective geospatial analysis was conducted using EMS records from March 17, 2024, to March 16, 2025. Violence was defined as gunshot wounds, stabbings, and physical assaults. Cases were aggregated by ZIP code of injury within the response zone and correlated with the Distressed Communities Index (DCI), a composite measure of socioeconomic well-being. Negative binomial regression, using ZIP-level Census population as an offset, generated rate ratios and 95% CIs to assess associations between LTOWB frequency and DCI metrics. ZIP codes with <500 residents were excluded per DCI methodology. A total of 220 patients received prehospital LTOWB across 22 ZIP codes. Transfusion incidence varied substantially, with higher-count ZIP codes generally showing higher DCI scores. Population-adjusted regression demonstrated a significant association between DCI score and LTOWB transfusion incidence (rate ratio: 1.03; 95% CI: 1.02-1.04), indicating a ~3% increase in expected transfusion rate per 1-point DCI increase. Significant DCI components (p < 0.05) included lower educational attainment, higher poverty and unemployment, reduced median income ratios, non hispanic white polulation and increased housing vacancy. LTOWB incidence was not significantly associated with employment growth, business establishment change, or other racial/ethnic composition. In this urban setting, ZIP codes with the highest rates of prehospital LTOWB use for hemorrhagic shock secondary to violence corresponded with higher DCI scores, suggesting an association between socioeconomic distress and injury burden. These findings highlight the value of geospatial and social determinant analyses in guiding targeted prevention strategies, violence interruption initiatives, and resource planning to reduce traumatic injury burden in high-risk communities. (J Trauma Acute Care Surg 2026;00:000-000 Copyright © 2026 Wolters Kluwer Health, LLC. All rights reserved.). Prognostic/Epidemiological; Level III.