The Association of Traumatic Brain Injury with Neurologic and Psychiatric Illnesses among Individuals Experiencing Homelessness: A Systematic Review and Meta-analysis.

Homeless individuals are more likely than others to experience a traumatic brain injury (TBI), but it is uncertain if such individuals are more likely to experience neuropsychiatric illnesses. A systematic review was performed with searches in Medline, Embase, and PsychINFO for studies reporting on homeless persons with TBI and neuropsychiatric illnesses. A random-effects model was used to calculate odds ratios for having any neuropsychiatric diagnosis. Of 420 articles indexed, 19 were included for systematic review and 17 for meta-analysis reporting on 11,474 and 8,757 individuals, respectively. The pooled odds of a homeless individual with a TBI having any neurologic illness were 2.57 (95% CI [1.97, 3.44]; I2 = 68.0%) and 2.01 (95% CI [1.81, 2.25]; I2 = 79.2%) for any psychiatric illness. The odds of having a neuropsychiatric illness among homeless individuals with TBI are substantially higher than in the domiciled population with TBI.