Patients with traumatic brain injury (TBI) are at risk of developing different forms of dementia. Past studies have restricted analysis to the risk associated with brain injury severity. In our recent study supported by the Alzheimer’s Association, we observed a difference between male and female patients of similar age and injury severity in the relative risk and time to develop dementia but were left uncertain what caused the difference– sex (i.e., biological characteristics) or gender (i.e., socially constructed roles and behaviors). We aim to answer this question.
This pilot study aims to study risk and protective factors concerning dementia evolution after traumatic brain injury from the lens of biological sex and socially constructed gender. This is a population-based cohort study of all Ontario residents with a diagnosis of traumatic brain injury. Universal health care in Ontario, Canada covers all medically necessary physician and hospital services at the point of care. The study period covers two decades. Risk and protective factors (i.e., exposures) are nested within groups of social, health-, and environment-related. The outcome variable is dementia and time to develop dementia in male and female patients with TBI. Our methodology will cover the following steps. First, we will study how male and female patients with and without brain injury differ in exposure when we match them individually for age, sex, socioeconomic status, and place of living. Second, utilizing social, health-, and environment-related factors that differentiate male and female patients with and without brain injury, we will create a Gender Score. We will study factors within the Gender Score, to determine whether they are reflecting biological differences or gender norms and behaviors. Third, we will build predictive models of dementia and the time to develop dementia using sex and Gender Score as primary predictors. Finally, we will validate the results and report them to the scientific community and the funders. This study will generate knowledge whether it is biological sex, socially constructed gender, or both, that drive differences in dementia evolution after injury. The results will have an important impact on research, policy, and practice because they will lay the groundwork for future research grant proposals around building hypothetical frameworks of prevention, with strong implications for future funding for prevention interventions.