Sex differences in mild traumatic brain injury: a multicenter propensity-matched two-year cohort analysis.

BACKGROUND: Mild traumatic brain injury (mTBI) is often considered low risk, yet growing evidence suggests that outcomes may differ by sex, and when explored, also by gender. We examined sex-associated differences in structural injury, acute-care complications, and neuropsychiatric diagnoses for patients with mTBI. METHODS: This retrospective cohort study used the TriNetX Global Health Research Network to identify adults (≥18 years) diagnosed with mTBI (Glasgow Coma Scale 13-15) between 2010 and 2022. Patients were identified using ICD-10 codes (S06, S09, R40.2411-R40.2413), with exclusion of moderate and severe TBI. Outcomes were assessed at 1 month, 6 months, 1 year, and 2 years. Propensity score matching (1:1) was performed to balance demographic and clinical characteristics. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using logistic regression. RESULTS: Among 26,829 patients with mTBI, 9,999 (37.3%) were female and 16,830 (62.7%) were male. After matching, 9,649 patients remained in each cohort. Female patients had significantly lower odds of intracranial lesions, including epidural hematoma (OR 0.59, 95% CI 0.46-0.76) and subdural hematoma (OR 0.79, 95% CI 0.73-0.87), as well as lower odds of mortality, intensive care unit admission, neurosurgical intervention, and systemic complications across follow-up. In contrast, females demonstrated higher odds of anxiety (OR range 1.86-1.95) and depression (OR range 1.63-1.81) at all time points. CONCLUSIONS: In this large cohort, women with mTBI exhibited lower structural and acute-care burden but higher long-term neuropsychiatric sequelae. These findings highlight the importance of sex- and gender-informed approaches to acute risk stratification and longitudinal mental health follow-up after mTBI.