The effect of traumatic brain injury on the health of homeless people

Background: We sought to determine the lifetime prevalence of traumatic brain injury and its association with current health conditions in a representative sample of homeless people in Toronto, Ontario. Methods: We surveyed 601 men and 303 women at homeless shelters and meal programs in 2004-2005 (response rate 76%). We defined traumatic brain injury as any self-reported head injury that left the person dazed, confused, disoriented or unconscious. Injuries resulting in unconsciousness lasting 30 minutes or longer were defined as moderate or severe. We assessed mental health, alcohol and drug problems in the past 30 days using the Addiction Severity Index. Physical and mental health status was assessed using the SF-12 health survey. We examined associations between traumatic brain injury and health conditions. Results: The lifetime prevalence among homeless participants was 53% for any traumatic brain injury and 12% for moderate or severe traumatic brain injury. For 70% of respondents, their first traumatic brain injury occurred before the onset of homelessness. After adjustment for demographic characteristics and lifetime duration of homelessness, a history of moderate or severe traumatic brain injury was associated with significantly increased likelihood of seizures (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.8 to 5.6), mental health problems (OR 2.5, 95% CI 1.5 to 4.1), drug problems (OR 1.6, 95% CI 1.1 to 2.5), poorer physical health status (-8.3 points, 95% CI -11.1 to -5.5) and poorer mental health status (-6.0 points, 95% CI -8.3 to -3.7). Interpretation: Prior traumatic brain injury is very common among homeless people and is associated with poorer health.