Kushel MB, Vittinghoff E, Haas JS. Factors Associated With the Health Care Utilization of Homeless Persons. JAMA. 2001;285(2):200-206. doi:10.1001/jama.285.2.200
Author Affiliations: Division of General Internal Medicine, San Francisco General Hospital, Department of Medicine (Drs Kushel and Haas), Department of Epidemiology and Biostatistics (Dr Vittinghoff), Institute for Health Policy Studies (Dr Haas), University of California, San Francisco.
Caring for the Uninsured and Underinsured Section
Editors: William L. Roper, MD, MPH, University of North Carolina at
Chapel Hill; Carin M. Olson, MD, Contributing Editor, JAMA.
Context Homeless persons face numerous barriers to receiving health care and
have high rates of illness and disability. Factors associated with health
care utilization by homeless persons have not been explored from a national
Objective To describe factors associated with use of and perceived barriers to
receipt of health care among homeless persons.
Design and Setting Secondary data analysis of the National Survey of Homeless Assistance
Providers and Clients.
Subjects A total of 2974 currently homeless persons interviewed through homeless
assistance programs throughout the United States in October and November 1996.
Main Outcome Measures Self-reported use of ambulatory care services, emergency departments,
and inpatient hospital services; inability to receive necessary care; and
inability to comply with prescription medication in the prior year.
Results Overall, 62.8% of subjects had 1 or more ambulatory care visits during
the preceding year, 32.2% visited an emergency department, and 23.3% had been
hospitalized. However, 24.6% reported having been unable to receive necessary
medical care. Of the 1201 respondents who reported having been prescribed
medication, 32.1% reported being unable to comply. After adjustment for age,
sex, race/ethnicity, medical illness, mental health problems, substance abuse,
and other covariates, having health insurance was associated with greater
use of ambulatory care (odds ratio [OR], 2.54; 95% confidence interval [CI],
1.19-5.42), inpatient hospitalization (OR, 2.60; 95% CI, 1.16-5.81), and lower
reporting of barriers to needed care (OR, 0.37; 95% CI, 0.15-0.90) and prescription
medication compliance (OR, 0.35; 95% CI, 0.14-0.85). Insurance was not associated
with emergency department visits (OR, 0.90; 95% CI, 0.47-1.75).
Conclusions In this nationally representative survey, homeless persons reported
high levels of barriers to needed care and used acute hospital-based care
at high rates. Insurance was associated with a greater use of ambulatory care
and fewer reported barriers. Provision of insurance may improve the substantial
morbidity experienced by homeless persons and decrease their reliance on acute
Homeless persons face numerous barriers to receiving appropriate health
care. Prior research has documented that homeless persons have high rates
of physical illness, mental illness, substance abuse,1- 3
and early mortality.4- 7
They are more likely to be admitted to the hospital8
and to have increased length of hospitalization9
and may present a substantial burden on the resources of safety-net hospitals
and clinics.10 Despite having a higher burden
of illness, homeless persons have fewer encounters with ambulatory care than
nonhomeless persons.11 For homeless persons,
health care competes with more immediate needs, such as obtaining adequate
food and shelter.12 However, given the opportunity,
homeless persons are willing to obtain health care for chronic conditions
if they believe such care to be important.13
While prior research has described homeless persons' dependence on acute
care, such as hospital-based services,8,14- 17
the factors associated with utilization of health care in this population
have not been explored from a national perspective. Most research has focused
on homeless persons residing in specific cities. Wide variations in characteristics
and utilization patterns between different regions make national policy implications
difficult to discern from local studies. Homelessness has proven to be a durable
problem in diverse regions of the country, creating a large toll of human
suffering as well as a complex burden on the safety-net health care system.
National policy decisions geared toward decreasing barriers to appropriate
health care utilization are needed.
We performed a secondary data analysis of the factors associated with
the use of ambulatory care services, emergency departments, and acute care
hospital services and self-perceived barriers to medical care among currently
homeless persons included in the National Survey of Homeless Assistance Providers
and Clients (NSHAPC).18 The survey, performed
in October and November 1996 by the Census Bureau, was designed to enroll
a nationally representative sample of persons who used homeless services in
the United States. The Census Bureau used criteria established in the McKinney
Act of 1987 to establish homelessness.19 Representative
areas were chosen for urban, suburban, and rural regions. The 28 largest metropolitan
statistical areas were chosen to represent urban areas. Twenty-four areas
were randomly sampled from the small- and medium-sized metropolitan statistical
areas to represent suburban and urban fringe areas, and 24 groups of rural
counties or parts of counties were randomly sampled to represent rural areas.
Subjects were selected among people who used homeless services. The
Census Bureau documented and surveyed homeless service providers (hereafter
includes homeless assistance programs, including shelters, transitional housing
programs, permanent housing programs for fomerly homeless people, food pantries,
soup kitchens, etc) in the designated areas and then selected a systematic
sample of programs.20 Programs were chosen
with a probability proportional to size. Program visits for data collection
were scheduled at randomly chosen times and dates, and subjects were randomly
selected to complete in-person interviews. Interviews were conducted on-site
by census field workers. All subjects were interviewed in person by trained
interviewers and were paid $10 for their participation. For our analysis,
we excluded formerly and never homeless subjects.
Factors associated with the use of ambulatory care, emergency departments,
and acute care hospital services and perceived barriers to health care were
analyzed in 5 domains: sociodemographic characteristics, physical health,
mental health, substance abuse, and history of homelessness. Sociodemographic
characteristics included age (<25 years, 25-49 years, and ≥50 years),
sex, race/ethnicity (non-Latino White, non-Latino African American, Latino,
or Native American), and veteran status (yes or no). Type of locale (ie, urban,
suburban, or rural) was determined by the interviewer based on location of
site. Medical insurance (yes/no) was determined by self-report.
Physical health was represented by self-reported chronic comorbidity.
Subjects were asked to report if they had diabetes, anemia, hypertension,
heart disease or stroke, liver disease, arthritis or joint conditions, cancer,
physical disability, or human immunodeficiency virus (HIV) infection or acquired
immunodeficiency syndrome (AIDS). The number of positive responses were summed
and categorized as 0, 1, 2, and 3 or more.
Mental illness was screened by using a modified version of the Addiction
Severity Index (ASI).21 According to convention,
a score greater than 0.25 on the psychological scale was considered positive
for mental illness. The ASI has been validated in homeless populations as
a tool for screening for the likelihood of having mental health conditions
and drug and alcohol abuse.22,23
As in the report of the NSHAPC,24 subjects
who did not meet the criterion for mental health conditions on the ASI were
characterized as having a mental health condition in the past year if they
reported mental health service use (ie, medication, hospitalization, or outpatient
treatment) or repeated episodes of disabling symptoms. Similarly, alcohol
abuse was screened for by the modified ASI (score ≥0.17 in the alcohol
realm) by self-reported heavy drinking in the past year or use of alcohol
treatment services in the past year. Drug abuse in the past year was screened
for (ASI score ≥0.10 in the drug use realm) by self-report of injection
drug use, heavy drug use, or treatment for drug abuse in the past year.
Respondents were asked where they had spent the majority of the time
since becoming homeless. Responses were categorized as "literally homeless"
if they had spent the majority of their time homeless staying on the street
or in shelters and as "marginally housed" if they had spent the majority of
their time staying in transitional housing, hotel, or a friend's or relative's
The outcome variables included 3 service utilization variables and 2
measures of barriers to care. The utilization variables were use of ambulatory
care services, emergency departments, and inpatient medical and/or surgical
hospital services during the past year. The measures of perceived barriers
to care were self-reported inability to receive needed care and the inability
to comply with needed prescription medicine in the past year.
Subjects were asked to report all places where they had received medical
care in the past year, including inpatient hospitalization and the emergency
department. The number of times visited and the length of stay were not obtained.
Thus, history of hospitalization and emergency department use were each dichotomized
yes or no. The following responses were included as indicating receipt of
ambulatory care: hospital outpatient department, Veterans Affairs (VA) outpatient
department, physician or nurse in homeless shelter, health care for the homeless
clinic, community health clinic, migrant health clinic, or private physician's
office. A respondent who did not report having received care at 1 of those
sites was considered to not have had an ambulatory care visit in the preceding
year. The subject's self-report was not validated by medical records.
Respondents were asked if they had needed care from a physician or nurse
in the past year but were unable to obtain it. If they responded affirmatively,
they were classified as being unable to receive needed care in the past year.
Respondents were asked whether they were supposed to be taking a prescription
medication. Only persons who reported being prescribed medication were included
in the analysis of compliance; such persons were asked if they had been able
to take the medication as prescribed. If they reported no, they were classified
as having been unable to comply with prescription medication.
Bivariate relationships between independent variables and the 5 outcome
variables were assessed using unadjusted logistic regression models. Multivariable
logistic models were chosen based on the importance of bivariate relationships
and prior hypotheses. All regression analyses used weights provided by the
Census Bureau to make parameter estimates nationally representative. These
weights are based on the inverse of the probability of being included in the
sample and incorporate information about the complexities of the sampling
procedure. They therefore approximate the number of persons in the US population
in 1996 that each survey respondent can be taken to represent.24
Because stratum and primary sampling unit identifiers were withheld in the
public use dataset to protect participant confidentiality, we used the approximation
recommended by the Census Bureau to account for variance inflation resulting
from the multistage sampling design. Specifically, the SEs for all estimates
(both unadjusted and adjusted) are inflated by the square root of the mean
design effect. The design effect estimate provided by the Census Bureau was
3.0.24 In turn, confidence intervals (CIs)
and P values were calculated using the inflated SEs.
Finally, because homeless persons with medical comborbidities or prescription
drug use may be at greatest risk for barriers to care, we performed a subgroup
analysis for the outcome of inability to obtain needed care. Also, to examine
whether those who were eligible for insurance were receiving it, we explored
the insurance patterns of veterans, who because of their low incomes, were
entitled to VA health benefits.25
Of the 4207 respondents to the NSHAPC, 2974 were currently homeless,
688 were formerly homeless, and 545 never homeless. Of the currently homeless
subjects, 2806 (94.4%) initially approached for participation completed the
interview: 168 of the subjects either refused participation (n = 51), were
unable to complete the interview secondary to intoxication (n = 2), were mentally
or physically incapable (n = 9), were unavailable (n = 69), or were ineligible
for participation (n = 37); replacement subjects were selected. Of the respondents,
50 (1.1%) had a friend or family member assist them with their responses.
We restricted the analyses to the 2974 respondents who were homeless
at the time of the survey. The currently homeless population overall is predominantly
young (72.6% between 25 and 49 years) and male (67.6%) (Table 1). More than 90% were single, but 42.8% of respondents were
married previously. At the time of the survey, 40.3% of women and 3.4% of
men were living with a child. More than two thirds of the respondents were
located in urban areas. Overall, 22.4% of the respondents were veterans: 32.6%
of the men and 1.1% of the women. Of the veterans, 89% reported having received
an honorable discharge. The respondents were very poor; less than one fourth
of respondents noted income, from all sources, of greater than $600 per month.
The median duration of homelessness for the sample was 1 year; 15.1%
were homeless for more than 5 years. Of the respondents, 44.8% were categorized
as literally homeless, and the remainder were categorized as marginally housed.
The cohort exhibited high rates of chronic medical health conditions,
chronic mental health conditions, and drug and alcohol abuse. Almost three
fourths had a mental health condition or drug or alcohol abuse; many reported
having more than 1 condition. More than half (55.6%) of the respondents reported
being uninsured, and more than one fourth (26.7%) reported no contact with
nurses, physicians, clinics, and hospitals in the past year. Among veterans,
the uninsured rate was 48.4%; only 26.8% had VA insurance.
Ambulatory Care. Overall, 62.8% of currently homeless respondents reported receiving
medical care at an outpatient site, excluding the emergency department, during
the past year (Table 2). The most
common sites included hospital outpatient clinics (27.9%), VA clinics (5.6%),
homeless shelters (with physician or nurse on-site) (10.4%), health care for
the homeless clinics (8.3%), community health clinics (22.0%), or a private
physician's office (19.4%). In the multivariate analysis, those with 3 or
more medical comorbid illnesses and those with medical insurance were more
likely to have received ambulatory care in the prior year than those who had
less than 3 comorbid illnesses or who were uninsured. There also was a trend
toward greater ambulatory care use by women (76.5%) vs men (56.4%) and by
those who were categorized as marginally housed (72.7%) vs those who were
categorized as literally homeless (51.5%).
Emergency Department Use. Overall, 32.2% of respondents received medical care in an emergency
department in the prior year (Table 2).
In the multivariate analysis, respondents with mental illness (odds ratio
[OR], 1.99; 95% CI, 1.04-3.81) and those with 2 medical comorbidities (OR,
2.59; 95% CI, 1.03-6.51) were significantly more likely to use the emergency
department than those without mental illness or comorbidity. Insurance was
not associated with emergency department use.
Hospitalizations. Almost one fourth of respondents (23.3%) had a hospitalization in the
prior year (Table 2). In the multivariate
model, insurance remained the only covariate significantly associated with
an increased likelihood of hospitalization (OR, 2.60; 95% CI, 1.16-5.81).
Veterans and those with 3 or more medical comorbidities were at an increased
risk (OR, 2.02; 95% CI, 0.92-4.44 and OR, 2.59; 95% CI, 0.91-7.37, respectively).
African Americans were statistically significantly less likely (OR, 0.47;
95% CI, 0.23-0.94) than non-Latino whites to have had a hospitalization in
the prior year.
Ability to Obtain Medical Care When Needed. One fourth of respondents (24.6%) reported that at some point in the
past year they had needed medical care that they had not been able to receive
(Table 3). After adjustment, those
with medical comorbidities were more likely to report an inability to receive
needed care than those without comorbidities. Respondents who had insurance
were less likely to report poor access. Because those with a medical comorbidity
or the need for a prescription medication may be at greater risk for barriers
to care, we specifically analyzed the correlates of barriers to care for this
subgroup. There were no significant differences between this subgroup and
the cohort as a whole.
Ability to Comply With Prescribed Medications. Overall, 40.9% (1201/2936) of respondents stated that they were supposed
to be taking a prescription medicine, and 32.6% (392/1201) reported they were
unable to comply with these medications. When weighted to reflect the US population,
32.1% noted that they were unable to comply with prescription medications
(Table 3). In the multivariate
model, respondents aged 50 years and older and respondents with insurance
were significantly less likely to report difficulty with medication compliance
than younger respondents and the uninsured (P≤.05).
This study confirms on a national scale what previous research found
at the local level; homeless persons reported high rates of acute hospital-based
care, low rates of ambulatory care, and difficulty accessing health care.
Our finding of an association between insurance status and increased use of
ambulatory care and decreased barriers to care reflects previous research
for housed and homeless persons alike: medical insurance enables the use of
ambulatory care and decreases barriers to care.
Despite evidence of poorer health, homeless persons in our study were
less likely than the overall US population to report an ambulatory care visit
in the previous year. Three fourths of persons with US homes had at least
1 ambulatory visit in the prior year, compared with 63% of homeless persons.26 Consistent with prior research, our study demonstrated
that homeless persons are more likely to use emergency departments than the
population as a whole.27- 29
Hospitalization rates of homeless persons in this study were 4 times that
of the US norms; these results parallel those in other studies.8,30
In the United States, only persons older than 65 years had similar rates of
hospitalization as those in our study, whose median age was 37 years.26
Differences in insurance status may explain part of the disparity in
ambulatory care use. In our study, having insurance was associated with increased
likelihood of having had an ambulatory care visit. While 17% of the US population
was uninsured in 1997,26 56% of homeless persons
were; this is approximately 50% higher than the US poverty population.31 Prior studies have found uninsured rates among homeless
persons ranging between 30.1% and 71.6%.16,32,33
Among persons with homes, having insurance enables receipt of nonurgent discretionary
health care.34- 36
Prior research has suggested that insurance status is correlated with homeless
persons' ability to seek nonurgent medical care,32,37
have a regular site of care that is not the emergency department,15 and receive inpatient treatment for alcohol and drug
abuse disorders and mental illness.33 In our
study, insurance status was not correlated with emergency department use,
thus suggesting that use of the emergency department may not be sensitive
to insurance status.
We included veterans, who by virtue of their poverty qualify for VA
benefits, to analyze whether homeless persons were receiving insurance benefits
to which they were entitled. Almost 90% of veterans in our study report having
received an honorable discharge, making them theoretically eligible for these
benefits. Despite this, almost half of homeless veterans were uninsured; only
one fourth had VA insurance. These data support prior research that suggests
that a substantial portion of homeless persons remain uninsured despite meeting
More stable sheltering arrangement, which previously has been found
to influence health care utilization,32 was
associated with a trend toward greater use of ambulatory care in our study.
The association with ambulatory care, reflecting that seen in other studies,15 suggests that stable housing may improve homeless
persons' ability to seek nonurgent care.
Mental illness is associated with health service utilization in both
homeless and nonhomeless populations.38- 40
In our study, mental health conditions were correlated with emergency department
use but not ambulatory care. Alcohol and drug abuse also are common among
homeless persons.41,42 We found
rates of substance abuse comparable with previous studies. In this sample,
neither alcohol nor drug abuse was associated with health service use in multivariate
models. This may be because our study was unable to look at repeated episodes
of health service use: we were unable to ascertain if alcohol and drug abuse
place homeless persons at the risk of becoming repetitive users of medical
Our study had several limitations. Because subjects were sampled from
those using homeless assistance services, they do not represent those who
do not use services or those in communities that have few or no homeless assistance
services. However, a study of homeless persons in San Francisco found that
88% of those considered literally homeless had used either a homeless shelter
or a food line in the previous 30 days.43 The
NSHAPC captured a far more extensive range of homeless service providers,
suggesting that their methods were likely to capture the vast majority of
homeless persons in communities where there were services provided.
The survey did not acquire information on the frequency of use of medical
services. For example, we could not distinguish people with 1 hospitalization
from those with several. This limited our ability to ascertain whether certain
subgroups were at risk of becoming frequent users of medical care; prior research
has suggested that those with substance use or mental health conditions are
likely to fall in this category.29
All data were by respondent self-report without independent confirmation.
Research on self-report of homeless persons has suggested that while they
are reasonably accurate reporters of the use of health care services in the
past year, they are not accurate reporters of visit frequency.44
Prior research that validated homeless persons' self-report of health care
utilization found that they were only slightly less accurate in their reporting
than the population at large.32,44,45
While many studies document that insurance facilitates the use of health
care services, it is possible that the associations observed in these data
are not causal. Clinics and hospitals may facilitate health coverage reimbursement
among eligible patients under their care. We were unable to distinguish whether
the association between insurance and compliance with medications reflected
insured persons' improved ability to purchase medication, differences in the
patient-physician encounter, or unmeasured differences in homeless persons
with and without insurance.
Finally, since our study was descriptive, multiple comparisons were
made, thus increasing the potential for type I errors. Accounting for the
effects of multistage sampling using an estimate of the mean design effect
reduces the reliability of CIs for logistic model ORs. Since actual design
effects may vary by both independent and dependent variables, use of the mean
in all situations could have liberal or conservative effects. This estimate,
however, is the most accurate available.
Our study provides a national perspective on the health care needs and
utilization of homeless persons. Having insurance was consistently associated
with indicators of improved access to care; however, the majority of respondents
lacked insurance. Nearly half of veterans were uninsured, despite meeting
criteria for VA health benefits. These data suggest that improving insurance
rates among homeless persons will require not only expansion of eligibility
but also improvements in identifying and enrolling those who qualify. The
provision of medical insurance may favorably impact homeless persons' ability
to obtain ambulatory health care and decrease the tendency among homeless
persons to delay needed care. This, in turn, may contribute to decreasing
high rates of emergency department use and inpatient hospitalizations and
may improve morbidity among homeless persons.