De Ritis Ratio as a Prognostic Marker for Mortality in Moderate-to-Severe Traumatic Brain Injury: A Propensity Score-Matched Analysis

<b>Background:</b> Traumatic brain injury (TBI) remains a significant cause of global mortality and morbidity. This study investigated the association between initial De Ritis ratio (serum AST/ALT) and mortality in moderate-to-severe TBI patients. <b>Methods:</b> This retrospective study analyzed 4415 adult patients with moderate-to-severe TBI (head/neck AIS ≥ 3) from January 2009 to December 2020. Patients were categorized into three groups based on De Ritis ratios: ≤1.2 (<i>n</i> = 1296), 1.2 < ratio ≤ 1.64 (<i>n</i> = 1499), and >1.64 (<i>n</i> = 1620). Propensity score matching was performed to adjust for baseline characteristics including age, sex, comorbidities, Glasgow Coma Scale, and Injury Severity Score. <b>Results:</b> Higher De Ritis ratios were also associated with increased intensive care unit admission rates and longer hospital stays. After propensity score matching, patients with De Ritis ratio > 1.64 showed significantly higher mortality rates compared to the control group (10.3% vs. 7.9%, odds ratio (OR) = 1.33, 95% confidence interval (CI) 1.01-1.77, <i>p</i> = 0.046). No significant mortality difference was found between patients with De Ritis ratio ≤1.2 and the control group. <b>Conclusions:</b> Initial De Ritis ratio>1.64 serves as an independent predictor of mortality in moderate-to-severe TBI patients. This readily available laboratory parameter could provide valuable prognostic information for early risk stratification in TBI management.