Homeless CKD patients experience increased kidney failure and premature death

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The approximately 3.5 million people who are homeless each year in the United States experience numerous barriers to obtaining appropriate and effective medical care, and they have high rates of physical illness, mental health disorders, and substance abuse.

“Prior studies suggested that risk factors for chronic kidney disease such as diabetes mellitus and hypertension might be elevated among homeless individuals, but the elusive nature of this population has limited our understanding of the long-term outcomes of chronic diseases in this population,” said Yoshio Hall, MD, of the University of Washington, Seattle. “Our research attempts to address this knowledge gap and provides a rare glimpse into the characteristics and adverse health outcomes of this marginalized group.”

Homelessness and health

To examine the associations between homelessness and the clinical outcomes of chronic kidney disease (CKD) among adults, Hall and his team analyzed the medical records of 15,343 adults with moderate to advanced CKD (stages 3–5) who received outpatient care from 1996 to 2005 from the Community Health Network, which along with a consortium of not-for-profit primary care clinics forms the backbone of San Francisco’s healthcare safety net system and offers an array of healthcare services including primary care, specialty care, and acute care. Their results were published recently in the Clinical Journal of the American Society of Nephrology.

A total of 858 (6 percent) of the adults in the study were homeless. The main outcome measures of this retrospective cohort study were emergency department visits, hospitalizations, and time to ESRD or death.

“We hypothesized that in this resource-poor setting, homeless adults would experience worse morbidity and mortality, and that they would use healthcare resources far less efficiently than indigent peers with stable housing,” said Hall. “We further hypothesized that the worse health outcomes among the homeless would be in part attributable to higher rates of substance use and other risk factors for death and disease progression.”

The researchers found that homeless adults were younger, were disproportionately male and uninsured, and had far higher rates of depression and substance abuse than adults with stable housing. Also, the large majority of homeless people in the study were destitute, reporting an annual income of less than $5000, and most were unemployed, disabled, and/or receiving public assistance. Compared with indigent adults living in stable housing, those who were homeless had a higher prevalence of mild or heavy proteinuria, as well as more advanced CKD.

The average follow-up time was 2.6 years among homeless participants and 2.7 years among housed participants. Over 57,698 person-years, 83 (10 percent) homeless adults died and 31 (4 percent) progressed to ESRD compared with 901 (6 percent) and 528 (4 percent) housed counterparts, respectively. The crude rates of ESRD or death were 1.8-fold higher among homeless adults relative to housed adults. After demographic factors, substance abuse, comorbid conditions, and laboratory variables (index kidney function, proteinuria, hemoglobin, and serum albumin concentrations) were taken into account, homeless adults had a 28 percent increased risk for the development of ESRD or death.

The investigators noted that the association of homeless status and the risk of ESRD or death differed according to substance abuse. Specifically, among individuals with a history of substance abuse, there was a trend toward a higher adjusted risk of ESRD or death among the homeless compared with those in stable housing. A link between homeless status and the risk of ESRD or death did not significantly differ by sex, race or ethnicity, the presence or absence of diabetes, or initial kidney function measures.

“This important study sheds new light on a serious problem,” said Stephen Hwang, MD, who was not involved with this research. “Clinicians who take care of disadvantaged patients have long suspected that the combination of homelessness and chronic kidney disease is potentially lethal, and this study confirms that impression,” he explained. Hwang’s work at St. Michael’s Hospital in Toronto, Canada, focuses on improving the health of people who are homeless or vulnerably housed and on deepening our understanding of housing as a social determinant of health.

The investigators also found that during follow-up, half of homeless adult patients visited the emergency department more than nine times and experienced more than five hospitalizations. Twenty-five percent made more than 20 visits to the emergency department. Most housed patients experienced one or no emergency department visits or hospitalizations.

Also, homeless adults were significantly less likely than were housed adults to have received any nephrology care, even after differences in sociodemographic factors, comorbid conditions, substance abuse, kidney function, proteinuria, hemoglobin, and serum albumin concentrations were controlled for.

Addressing unmet needs

These findings indicate that homeless adults with CKD have increased morbidity and mortality and use costly emergency care services far more frequently than do their peers who are stably housed. “Sadly, for most homeless persons, securing adequate shelter, food, and clothing often competes with regular healthcare and results in more frequent use of costly acute care services to manage chronic conditions,” said Hall.

He noted that the use of these costly services might decline among homeless individuals when services such as transportation, social work, nutrition, and access to healthcare providers become available. “Nationwide concerns about high public costs incurred by homeless people have provoked various housing interventions to eliminate chronic homelessness. We feel that the degree to which interventions aimed at providing permanent, affordable housing, and other supportive services can attenuate these health inequalities warrant additional investigation, as policymakers and researchers debate where and to whom these efforts should be applied,” said Hall.

“Hopefully, this study will provide an impetus to develop better strategies to help these patients, through both medical treatment and interventions to address the underlying problem of homelessness,” said Hwang.

Notes

[1] The article, entitled “Homelessness and Chronic Kidney Disease: A Cohort Study,” is available online at http://cjasn.asnjournals.org/.