Effect of anticoagulation on isolated traumatic brain injury mortality using TQIP database: a propensity score analysis stratified by head injury severity.

Introduction: The impact of anticoagulation (AC) on traumatic brain injury (TBI) outcomes remains varied in the literature. Previous studies often relied on single-center data, small sample sizes, or lacked adjustments for key confounding variables. This study used the population-based Trauma Quality Improvement Program (TQIP) database to analyze the effect of AC on isolated TBI mortality, hypothesizing that AC's impact varies with TBI severity. Methods: This retrospective cohort study analyzed data from 2020 to 2021 TQIP database. Patients with isolated TBI were identified using International Classification of Diseases, 10th revision codes. Exclusions included patients <18 years, penetrating trauma, and non-head injuries with Abbreviated Injury Scale (AIS) score >3. The majority of patients taking AC were in their 50s and above; therefore, they were stratified into AC and non-AC cohorts. Propensity score analysis adjusted for age, gender, and head AIS, stratified by TBI severity (mild, moderate, severe). Primary outcomes were in-hospital mortality and neurosurgical intervention (NSI), including craniotomy and intracranial pressure monitoring. Statistical analyses were performed using Stata V.17.0, with significance at p<0.05. Results: Among 118,775 patients with isolated TBI, 96,802 were >50 years, with 26,444 (27%) taking AC. Unadjusted mortality was higher in the AC group (6%) compared with the non-AC group (3%; ∆3%, p<0.001). Adjusted mortality differences showed significant AC effects in mild (∆1.3%, 95% CI 1.04% to 1.57%, p<0.001) and moderate TBI (∆7.9%, 95% CI 4.46% to 11.43%, p<0.001), but not severe TBI (∆3.14%, 95% CI 0.07% to 7.04%, p=0.11). No significant AC effect on NSI was observed after adjustment. Discussion: Preinjury AC increases mortality in patients with isolated TBI, with the magnitude of its impact varying by TBI severity. Future studies should explore AC's influence on intracranial blood volume and progression to further elucidate its role in TBI outcomes. Level of evidence: Level 3.