Three-Month Outcomes of Traumatic Brain Injury in the General Population: A Sunnybrook Traumatic Brain Injury Cohort Study

Traumatic brain injury (TBI) is common, disabling, and a growing public health concern. There are limited large-scale studies providing insight into factors associated with recovery in the general TBI population. Our aim was to identify factors associated with concussion/TBI symptom severity and return-to-work. We performed a prospective cohort study of concussion/TBI (predominantly mild to moderate) patients with data collected over a 20-year period (1998-2018). This is the first study presenting data from the Sunnybrook TBI (SUNTBI) cohort. Primary outcome at approximately 3-month postinjury was the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), and secondary outcome was return-to-work. Outcomes were analyzed using multivariable linear regression and logistic regression models, respectively. There were 2924 TBI patients included in the study. General Health Questionnaire (GHQ), a screening measure of current psychiatric symptoms, and all its subscales (depression, anxiety, somatic, and social) (<i>p</i> < 0.0001), and active litigation (<i>p</i> < 0.001) were significantly associated with higher RPQ scores. Notably, factors related to injury characteristics and severity were not (e.g., injury mechanism, TBI severity, and neuroimaging abnormalities). For return-to-work, having a professional occupation (<i>p</i> < 0.001) was significantly positively associated with return, while abnormal CT scan (<i>p</i> = 0.001), admission to hospital (<i>p</i> < 0.001), and higher GHQ score (<i>p</i> < 0.001) were negatively associated. In one of the largest observational studies of general population concussion/TBI patients to date, we found that psychiatric symptoms and litigation status were significantly associated with symptoms at 3 months, while factors related to the injury severity were not. We also observed a decoupling of factors that impact symptom score outcomes from return-to-work outcomes. These results have important implications for the management of at-risk TBI subpopulations and wider public policy considerations.