Article In Brief
In a prospective review of studies, researchers found the lifetime prevalence of any severity of traumatic brain injury (TBI) in homeless and marginally housed individuals was 53.1 percent, and the lifetime prevalence of either moderate or severe TBI was 22.5 percent.
More than half of homeless persons and others living in unstable housing situations suffer traumatic brain injury (TBI) at some point in their life, a rate that far exceeds the general population, according to a meta-analysis of studies from six countries including the US and Canada.
The study, published online December 2, 2019 in The Lancet Public Health, suggests that TBI is an often-overlooked problem in the homeless population, with brain injury putting people at risk for poorer health and functioning amid already difficult life circumstances.
“It is becoming increasingly clear that TBI can be both a cause and consequence of homelessness,” said an editorial accompanying the study.
TBI can put a person at increased risk for neurologic and psychiatric conditions, which could become part of a cascade of factors that lead to homelessness. At the same time, living on the street or in a shelter puts a person at risk for falls, assault, and other violent acts.
The new study on TBI and homelessness should be of interest to neurologists, who treat patients in the acute phases of TBI, perhaps absent much information on their everyday living status, the authors of the new study said. Being homeless or moving around from one couch to another may make it difficult for a TBI patient to follow up on hospital discharge instructions or adhere to a medication regimen.
On the other hand, neurologists may see a homeless person for a neurologic condition and not make the connection that the person experienced a past head injury that may be relevant to what is currently going on.
“Primary care providers and those working with this group (homeless people) should be aware of the prevalence and associated consequences of TBI,” concluded the study, whose senior author was William J. Panenka, MD, assistant professor of neurology and psychiatry at University of British Columbia, Vancouver. “Evaluating history of TBI might be relevant to a comprehensive assessment of homeless and marginally housed patients, who often have complex comorbidities.”
Dr. Panenka told Neurology Today that he hoped the new findings on TBI and homelessness might increase empathy among health care providers and the public alike, who may blame a homeless person's unsettling behavior on drug or alcohol addiction or severe mental health problems that are far beyond treatable.
“The fallout from TBI, including concentration, memory, and mood issues, are challenging enough for someone who is connected into the medical system and has a support network,” he said, “but for people who are barely surviving and have nowhere to go, that is a completely different equation.”
Dr. Panenka said his research team is doing a prospective study of about 500 people living in vulnerable housing in Vancouver to further study the impact of TBI, including as people get older. The team does periodic health assessments and neuroimaging. So far, about 200 CT scans have been done.
The new Lancet Public Health study noted that an estimated six million people experience homelessness annually in the US and the European Union. It also noted that homeless individuals are more likely to have a host of mental and physical health problems, including depression, drug and alcohol dependence, HIV, and hepatitis C.
The researchers said it has been hard to assess the reliability of estimates of TBI among homeless and marginally housed individuals, in part due to varying definitions of homelessness and differences in sampling methods. Homeless people may not necessarily seek medical attention for a head injury, so medical records are lacking
Study Design, Findings
For the new analysis on homelessness and TBI, the researchers searched the medical literature for studies published in English. Of 463 studies identified as relevant, they included 38 articles as part of their systematic review and 22 articles in a meta-analysis.
They found that the lifetime prevalence of any severity of TBI in homeless and marginally housed individual (based on 18 studies involving 9,702 individuals) was 53.1 percent, and the lifetime prevalence of either moderate or severe TBI (based on nine studies involving 5,787 people) was 22.5 percent.
“TBI was consistently associated with poorer self-reported physical and mental health, higher suicidality and suicide risk, memory concerns, and increased health service use and criminal justice system involvement,” the researchers reported.
Given the high incidence of TBI and the considerable number of homeless persons found to have evidence of traumatically-induced lesions visible with MRI, “clinicians might consider lowering the threshold for referral for neuroimaging specialists after head injury in homeless and marginally housed patients,” the researchers said. They said if concerning findings are identified on imaging, the patient can be connected with the necessary medical and social services.
“Furthermore, imaging findings might possibly inform the patient-caregiver relationship (e.g. by increasing understanding of challenging behaviors that might be attributable to damage visible on neuroimaging,” they noted. They said the availability of more stable housing for vulnerable populations might lower the incidence of TBI, though more study is needed.
James O'Connell, MD, president of Boston Health Care for the Homeless Program, said he was not surprised by the high rate of TBI identified in the new analysis.
“If you work out on the streets or in shelters you become painfully aware of all the head trauma and other physical trauma that people experience,” often multiple times over, said Dr. O'Connell, who is an assistant professor of medicine at Harvard Medical School. He said a common scenario is that someone falls or passes out and hits their head. Physical fights also erupt.
Dr. O'Connell said a homeless person's TBI history may in part, at least, explain their explosive or unpredictable behavior or shed light on why they their lives became unstable.
“The more you realize how complicated this population is, the more sympathetic you can become,” he said.
Dr. O'Connell has done studies among the Boston homeless population and found that about a quarter of the men can't read or write, probably due to learning difficulties that weren't addressed in school. A head injury can add to the cognitive deficits someone is already grappling with and make it even more difficult to function in life, he said, adding: “I worry that as we watch the population of homeless people age, we are going to see more of the behavioral problems from head trauma.”
Dr. O'Connell said identifying TBI only goes so far in helping society's most vulnerable people.
“I think we take exquisitely good care of head trauma,” he said, but getting people the ongoing medical and mental health help that they need is far more challenging.
“I think hospitals and skilled facilities offer excellent care for acute and post-acute head trauma patients,” he said, “but addressing the long-term sequela of TBI, including the complex medical and behavioral health needs, are much more difficult and the resources available to poor and vulnerable populations are scarce and hard to access.”
“If someone is diagnosed with traumatic brain injury that causes erratic behavior, they can easily fall into a health care nether world between psychiatry and neurology,” he said. BHCHP tries to fill some of the void in treating the complex needs of homeless persons through a network of over 40 shelter clinics, daily hospital clinics at Boston Medical Center and Massachusetts General Hospital, and 124 beds of medical respite care in the community.
Nicole Rosendale, MD, assistant professor of neurology at University of California, San Francisco, who studies TBI and homelessness, said she was pleased to see the publication of the latest study on the subject because “it is just starting to get the recognition it needs and deserves,” particularly among neurologists.
She published a study last year in Neurology, which used a California inpatient database, that found that homeless persons being treated for a neurologic condition (mostly TBI or seizures) were 50 percent more likely to be readmitted to the hospital within 30 days compared with non-homeless neurologic patients.
“It suggests we are not doing very well taking care of these patients,” Dr. Rosendale said. “As a field we are comfortable with the medical aspects of traumatic brain injury, doing what's needed to take care of that person in the moment...(but) when a homeless person comes in with a brain injury it also requires a view toward what happens out of the hospital and what they now are at risk for.”
Dr. Rosendale, who is a neurologist at Zuckerberg San Francisco General Hospital and Trauma Center, said getting a thorough patient history is crucial to understanding how TBI impacts a homeless patient. She includes such questions as “What is your life like outside the hospital?” to identify the patient's needs beyond the immediate medical ones.
Stephen Hwang, MD, an internist, homelessness researcher, and director of the Centre for Research on Inner City Health at St. Michael's Hospital in Toronto, said “living on the streets or in a shelter is a hazardous environment.”
He said neurologists treating homeless patients should be aware of the possibility that a history of TBI could be the cause of behavioral issues, seizures or unexplained cognitive deficits. He helped craft recommendations issued in October 2018 by the National Health Care for the Homeless Council that focus on the care of patients who are homeless and living with the effects of TBI. It includes recommendations for assessment of possible deficits, including which screening tools to use.
“The fallout from TBI, including concentration, memory, and mood issues, are challenging enough for someone who is connected into the medical system and has a support network, but for people who are barely surviving and have nowhere to go, that is a completely different equation.”
—DR. WILLIAM J. PANENKA
Dr. Hwang, who does outreach to homeless people, recalled the case of a man he met recently at a shelter. The staff warned Dr. Hwang to “watch out for this guy because he can have these outbursts and be nasty.”
It turned out that the man had had a cerebral hemorrhage in his frontal lobe, which possibly could be a factor in his quickly shifting emotions.
Dr. Hwang, a professor at the University of Toronto, said no one had explained to the man or the shelter staff that his prior TBI history could be influencing his behavior. Dr. Hwang tried to connect the man to some services that could be helpful.
Dr. Hwang said, “Up to now, TBI and homelessness hasn't gotten as much attention as traumatic brain injury in football and hockey players. It's great to see this paper come out and recognize it.”
Drs. Panenka, Hwang, and Rosendale had no competing interests. Dr. O'Connell has received honorarium and travel expenses from St. Michael's Hospital and St. Michael's Foundation in Toronto.
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