The association between white blood cell-to-hemoglobin ratio and mortality risk in critical traumatic brain injury: insights from MIMIC-IV retrospective analysis.

backgroundThe white blood cell-to-hemoglobin ratio (WHR) is a composite biomarker indicative of both systemic inflammation and anemia. However, its association with all-cause mortality in intensive care unit (ICU) patients with traumatic brain injury (TBI) is unclear. This study aimed to evaluate the relationship between WHR and all-cause mortality among critically ill TBI patients.

methodsClinical information was extracted from the MIMIC-IV database. The main endpoint was 30-day all-cause mortality. Additional outcomes included 90-day and 1-year mortality. WHR values were divided into quartiles. Kaplan-Meier survival curves assessed interquartile survival differences. Cox regression models and RCS techniques were used to assess the link between WHR and death risk. Subgroup and sensitivity analyses tested the consistency of results.

resultsThe study included 2635 patients, with a median age of 70 years and 62% being male. A significant correlation was observed between elevated WHR and increased mortality across 30-, 90-, and 365-day intervals (log-rank P < 0.05). Cox models confirmed a dose-dependent increase in mortality risk across WHR quartiles (all P < 0.05). The RCS model demonstrated a significant U-shaped pattern between WHR and mortality, indicating nonlinear effects (P for overall <0.001; P for nonlinear <0.05). Robustness of the results was reinforced through subgroup comparisons and sensitivity verification.

conclusionElevated WHR strongly correlated with mortality in critically ill TBI patients. In the ICU setting, WHR provides valuable prognostic information to guide individualized treatment strategies.