Differences in admission to trauma centres by sex among adults with traumatic brain injury: a population-based cohort study

Background — Female patients face disparities in access to specialized health care, but whether similar disparities exist in access to trauma centres after traumatic brain injury (TBI) is unclear. We sought to examine the association between sex and admission to a lead trauma centre (a hospital designated as a level I or II trauma centre) among adults with TBI.

Methods — We conducted a population-based cohort study using provincial health administrative databases from Ontario, Canada. We included adults (aged ≥ 18yr) admitted to hospital with TBI between April 2009 and March 2020. Our main exposure was sex. The primary outcome was admission to a lead trauma centre. We used multivariable logistic regression, adjusting for age, Injury Severity Score, comorbidities, rurality, and income quintile. We reported odds ratios (ORs) and 95% confidence intervals (CIs). We estimated marginal risk differences using standardization. Sensitivity analyses included quantitative bias analysis of outcome misclassification.

Results — Among 55606 patients (39.0% female), 26.1% of females and 38.3% of males were admitted to a lead trauma centre. In the overall cohort, female patients were older, had more comorbidities, and were less likely to have severe injuries than male patients. After adjustment, females had significantly lower odds of admission to a lead trauma centre (OR 0.74, 95% CI 0.71 to 0.78), corresponding to an adjusted marginal risk difference of −4.7% (95% CI −5.4% to −4.0%). Findings were consistent across sensitivity analyses.

Interpretation — Female patients admitted to hospital with TBI were less likely than male patients to be admitted to specialized trauma centres, independent of clinical and socioeconomic factors. These results suggest inequities and underscore the need for system-level strategies to ensure equitable triage and transfer practices.