The Association Between Depression and Traumatic Brain Injury in Older Adults: A Nested Matched Case Control Study

Objective: Determine association between depression and traumatic brain injury (TBI) in the older adult home care population of Ontario, Canada (2003-2013). Method: A nested matched case control study was used, and data were retrieved for service users 65 years or older who received home care between 2003 and 2013. Incident TBI cases were matched to four controls by sex, age, and assessment date. Odds ratios and multivariable conditional logistic regression were completed. Results: 554,313 service users were included of which 5,215 (0.9%) had a TBI and 39,048 (7.0%) had depression. Fall history was an effect modifier. The association between depression and TBI was 1.10 (95% confidence interval [CI] = [0.93, 1.31]) for those without a history of falling, while for those with a history of falling it was 1.24 (95% CI = [1.03, 1.48]) after adjusting for education and Alzheimer's disease. Discussion: Depression is associated with sustaining a TBI in those with a history of falling.