Improving trauma mortality prediction: Stress Hyperglycemia Ratio‐Integrated Index versus traditional glucose‐integrated Stress Index in a retrospective cohort study

Abstract Background Stress hyperglycemia is a common response to trauma and critical illness, but conventional glucose measurements fail to distinguish stress‐induced from chronic hyperglycemia. The serum glucose‐to‐potassium ration, or stress index (SI), is a readily available marker that may reflect the severity of the physiologic stress response. The stress hyperglycemia ratio (SHR) is defined as the ratio of an acute glucose measurement to the patient's estimated chronic glucose level, typically derived from hemoglobin A1c. This study evaluates a novel stress hyperglycemia ratio‐integrated index (SHRI) against the traditional glucose‐intergrated SI for predicting trauma outcomes. Methods A retrospective cohort study analyzed 3197 trauma patients admitted to a Level I trauma center (2019–2023). SHRI was calculated as the stress hyperglycemia ratio (SHR = admission glucose/estimated average glucose from HbA1c) divided by serum potassium. SI was defined as glucose/potassium. Optimal cutoffs were established via receiver operating characteristic analysis. Propensity score matching controlled for confounders was performed to compare the patients in the SHRI‐high and SHRI‐low groups. Results Inhospital mortality was 4.5% (144 patients). Nonsurvivors had higher SHRI (median 0.39 vs. 0.31, p < 0.001) and SI (53.17 vs. 43.85, p < 0.001), but lower HbA1c (6.05% vs. 6.50%, p = 0.003) and diabetes prevalence (45% vs. 58%, p = 0.003). SHRI > 0.41 predicted mortality with superior discrimination (AUC 0.81 vs. 0.73 for SI, p < 0.05) and was associated with fourfold higher mortality. After matching, SHRI‐high patients maintained higher mortality (8.9% vs. 3.9%, p = 0.015), whereas matched SI‐high versus SI‐low mortality was similar (4.8% vs. 4.0%, p = 0.70). Conclusions SHRI provides superior prognostic information compared to SI by accounting for individual baseline glycemic status. This novel index could improve risk stratification and potentially guide management in trauma settings.