Traumatic Brain Injury and the Risk of Incident Dementia in Taiwan: A Population-Based Retrospective Cohort Study Using National Health Insurance Research Database

Objective: Traumatic brain injury (TBI) has been associated with an increased risk of dementia. The purpose of this retrospective cohort study was designed to investigate the traumatic brain injury and other medical and environmental risk factors associated with dementia. Patients and methods: Taiwan's National Health Insurance Research Database(NHIRD) was used. We included 7,497 patients received a diagnosis of dementia. Medical disorders and environmental risk factors in 387 patients with Alzheimer's disease (AD) were compared with 7,110 patients with non-AD dementias. Results: The AD group had a lower prevalence of cerebrovascular diseases (42.64% vs 49.13%; p = 0.0128) and respiratory disease (24.29% vs 30.07%; p = 0.0154). In multivariate analysis, the risk for AD was increased in patients with cerebrovascular diseases (Adjusted HR, 1.56; 95% CI, 1.33 - 1.82) and respiratory disease (Adjusted HR, 1.20; 95% CI, 1.01 - 1.42). Conclusions: In a clinical sample of NHIRD, patients with AD don't have a significantly higher risk of TBI after adjustments for selective confounding factors compared with non-AD dementia. Care must be taken in extrapolating from these results because this study was limited by lack of information regarding lifestyles, TBI severity, and methods used in treatments.