Associations Between Composite Host Vulnerability Score and Transfusion Outcomes After Trauma

Background and Objectives: Outcomes after trauma are traditionally attributed to injury severity and acute physiologic derangement. However, host vulnerability at presentation-reflecting underlying physiologic and nutritional status-may also be associated with bleeding severity and transfusion requirements following acute injury. Whether such vulnerability contributes additional risk information beyond established factors remains incompletely understood. Materials and Methods: We conducted a retrospective cohort study of adult trauma patients using a single-center trauma registry. Host vulnerability was assessed using a composite score (CE; range 0-3) based on admission hypoalbuminemia (<3.5 g/dL), anemia (hemoglobin < 11 g/dL), and reduced renal function (estimated glomerular filtration rate < 60 mL/min/1.73 m²). Primary outcomes were any blood transfusion and massive transfusion, defined as transfusion of ≥10 units of packed red blood cells within 24 h of admission. Associations between CE score and transfusion outcomes were evaluated using univariable and multivariable logistic regression models adjusted for age, Injury Severity Score (ISS), admission lactate level, and systolic blood pressure (SBP). Results: Among 4105 trauma patients, transfusion requirements increased progressively with higher CE scores. Rates of any transfusion rose from 21.7% in patients with CE 0 to 78.6% in those with CE 3, while massive transfusion increased from 1.9% to 23.1% across the same categories. In multivariable analyses, each 1-point increase in CE score was independently associated with higher odds of any transfusion (adjusted odds ratio [aOR] 3.21, 95% confidence interval [CI] 2.80-3.68) and massive transfusion (aOR 1.73, 95% CI 1.45-2.07). Conclusions: A composite score reflecting host vulnerability at presentation was associated with bleeding severity and transfusion requirements after trauma, beyond injury severity and acute physiologic factors. These findings suggest that simple laboratory-based markers may provide additional information for early risk stratification of hemorrhagic outcomes after trauma.