Summary

Chronic homelessness is a highly complex social problem of national importance. The problem has elicited a variety of societal and public policy responses over the years, concomitant with fluctuations in the economy and changes in the demographics of and attitudes toward poor and disenfranchised citizens. In recent decades, federal agencies, nonprofit organizations, and the philanthropic community have worked hard to develop and implement programs to solve the challenges of homelessness (Farrugia and Gerrard, 2015; Harris, 2016), and progress has been made. However, much more remains to be done. Importantly, the results of various efforts, and especially the efforts to reduce homelessness among veterans in recent years, have shown that the problem of homelessness can be successfully addressed.

The scope of the problem is substantial. In 2017, more than 550,000 people were staying in shelters or in places not intended for human habitation on a single night. That same year 86,962 individuals were considered chronically homeless, nearly 7 in 10 of whom were unsheltered (HUD, 2017b).

The evidence of health-related harm caused by chronic homelessness is substantial. Research indicates that individuals who experience homelessness are at higher risk for infectious diseases (including human immunodeficiency virus [HIV] and hepatitis), serious traumatic injuries, drug overdoses, violence, death due to exposure to extreme heat or cold, and death due to chronic alcoholism. Persons experiencing homelessness are more likely than housed persons to use hospital emergency departments for health care and to be admitted to the hospital because they are less likely to have health insurance and a usual source of health care and because their conditions cannot be appropriately cared for without safe and secure housing. Individuals experiencing homelessness have longer hospitalizations for the same illnesses as housed persons, often because it is simply neither safe nor humane to discharge them to the street when they are still recuperating from the condition that caused them to be hospitalized, even if they are no longer acutely ill (Salit et al., 1998).

Although a number of programs have been developed to meet the needs of persons experiencing homelessness, this report focuses on one particular type of intervention—that is, permanent supportive housing (PSH)—and its impact on health outcomes and costs.

PSH programs have two essential components: (1) the provision of non-time-limited housing, and (2) the provision of an array of voluntary supportive

services. Not all individuals experiencing homelessness require PSH. Although the US Department of Housing and Urban Development (HUD) prioritizes those experiencing chronic homelessness for PSH, eligibility is based on long-term disability status, experiences with homelessness or unstable housing, or experiences of multiple barriers in maintaining housing stability. Although people experiencing chronic homelessness are only one subpopulation of individuals experiencing homelessness who are eligible for PSH, they are the primary population of interest in this report. Other housing models have evolved to serve the needs of other subpopulations.

In addition, the committee acknowledges that while one key goal of PSH is to address homelessness for people experiencing chronic homelessness, because of its specific charge, this report focuses on the impact of PSH on health care outcomes and its cost-effectiveness. The report also addresses policy and program barriers that affect the ability to bring the PSH and other housing models to scale to address housing and health care needs.

COMMITTEE’S STATEMENT OF TASK

The Committee on an Evaluation of Permanent Supportive Housing Programs for Homeless Individuals was charged to address a fundamental question: To what extent have permanent supportive housing programs improved health outcomes and affected health care costs in people experiencing chronic homelessness? To answer this question, the committee focused on more specific questions, including the following:

• What is the evidence that permanent supportive housing improves health-related utilization and outcomes in homeless persons with serious, chronic, or disabling conditions (e.g., substance use disorders, serious mental illness, physical disabilities, chronic conditions such as diabetes, etc.)?
• How cost-effective is PSH for addressing homelessness and health outcomes compared with usual care¹ and alternative interventions?
• What are individual and other characteristics that may be associated with the health-related outcomes and costs of permanent supportive housing (e.g., age, health conditions, other demographics)?
• What characteristics of permanent supportive housing programs, if any, result in improved health outcomes and evidence of cost-effectiveness?
• How generalizable are the findings from studies evaluating outcomes associated with the use of permanent supportive housing in the chronically

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¹ Usual care is defined as services that an individual accesses in the absence of immediate referral to the other interventions.

• homeless to other homeless populations (e.g., families with children or disabled persons)?

• Are the outcomes associated with the use of permanent supportive housing translatable to other populations or systems (e.g., what are common characteristics that might translate to an institutionalized population)?
• What are the key policy barriers and research gaps associated with developing programs to address the housing and health needs of homeless populations?

In answering these questions, the committee took a broad approach and interpreted “health” to be more than access to health care for individuals and families experiencing homelessness. The committee conducted its assessment through a population health lens, which means considering factors such as food security, safe and secure housing, reliable and safe transportation, uncontaminated air and water, and freedom from personal violence, among other social determinants of health, to be necessary for good health at both the individual and population levels (NASEM, 2016; WHO, 2017). These social determinants of health are outside of the scope of the traditional health care system and requires that the focus be on “upstream” factors and the prevention, as well as the treatment, of illness (Cohen et al., 2014).

To respond to the last question on “key policy barriers and research gaps associated with developing programs to address the housing and health needs of homeless populations,” the committee looked primarily at barriers to the PSH program and what would be needed to bring it to scale to meet the needs of those experiencing chronic homelessness.

Limitations of the Evidence

The committee’s deliberations were limited by a less than robust literature and evidentiary base with which to assess the effect of individual and program characteristics on outcomes in PSH. The committee was disappointed to find that the existing literature lacks information on the type, intensity, frequency, or length of the needed services, as well as clear details on what constitutes “usual services” when comparing the efficacy of different models of PSH. The lack of data about these things effectively precluded generalizing who among individuals experiencing homelessness are most likely to benefit from the services and different models of PSH.

The committee also identified inconsistencies in definitions and characteristics of PSH, and limited understanding of key services or minimum standards of PSH. The evidentiary base for screening tools used in allocating housing services assistance is especially limited. These limits create barriers to the collection of data on health outcomes of persons utilizing PSH. Further, data systems are not

currently designed to integrate data on homelessness, health, and other characteristics, which limited the ability of the committee to draw conclusions on these connections.

Regarding its evaluation of the literature on cost-effectiveness of PSH, the committee notes that although many studies that have applied a pre-test/post-test design have shown marked cost reductions, the few carefully conducted randomized controlled trials that have been done have failed to show any significant reduction in costs or improvements in health.

Because of the many evidentiary shortcomings, the committee was able to conclude less than it had expected would be possible when embarking on its work. The committee’s conclusions and recommendations below highlight what additional research is needed to determine the effectiveness of PSH in addressing health outcomes and to clarify for whom and in which circumstances it may be most beneficial.

CONCLUSIONS AND RECOMMENDATIONS

Overall, except for some evidence that PSH improves health outcomes among individuals with HIV/AIDS, the committee finds that there is no substantial published evidence as yet to demonstrate that PSH improves health outcomes or reduces health care costs. However, while this was the inescapable finding based on an impartial review of the evidence available at the time of this assessment, the committee believes that housing in general improves health, and notes that PSH is important in increasing the ability of some individuals to become and remain housed. Remaining housed should improve the health of these individuals because housing alleviates a number of negative conditions that detract from their ability to achieve “a state of complete physical, mental and social well-being” (WHO, 1946).

Individuals who live on the street are subject to extremes of the elements (e.g., freezing temperatures, extreme heat, sun exposure, and rain); lack of places to wash, urinate, and defecate; lack of a place to lie without undue pressure on the skin; lack of refrigeration (for food or medicines) or cooking facilities; lack of privacy; lack of a place for social interaction; lack of a stable address for receiving services, receiving mail, or hosting family members or visitors; exposure to violence, victimization, drugs, and injection drug use; and lack of places for intravenous drug users to safely and cleanly inject with resultant increased risk for infections such HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV). Sustained housing provides a platform from which other physical, mental, and social concerns can begin to be addressed.

The committee’s conclusions and recommendations described below are divided into three categories: (1) addressing research gaps in understanding the impact of PSH on health and cost-effectiveness of the model; (2) improving our understanding of effects of individual characteristics on outcomes in PSH; and (3)

identifying policy and program barriers to bringing PSH and other housing models to scale. (The recommendation number indicates the chapter in the full report where the specific recommendation can be found.)

Addressing the Research Gaps

PSH and Health

As noted above, on the basis of currently available studies, the committee found no substantial evidence that PSH contributes to improved health outcomes, notwithstanding the intuitive logic that it should do so and limited data showing that it does do so for persons with HIV/AIDS. There are significant limitations with the current research and evidentiary base on this topic. Most studies did not explicitly include people with serious health problems, who are the most likely to benefit from housing. Of the studies that were more rigorous, the committee found that housing increases the well-being of persons experiencing homelessness.

Based on studies conducted over a 1- to 2-year period, PSH effectively maintains housing stability for most people experiencing chronic homelessness. Whether PSH can reduce chronic homelessness for these individuals for longer periods of time will only be known once the results of longer term studies are available. Longer term randomized controlled trials that integrate health and housing data are also needed to fully assess the impact of PSH on health outcomes. The committee acknowledges the importance of housing in improving health in general, but it also believes that some persons experiencing homelessness have health conditions for which failure to provide housing would result in a significant worsening of their health. Said differently, notwithstanding that housing is good for health in general, the committee believes that stable housing has an especially important impact on the course and ability to care for certain specific conditions and, therefore, the health outcomes of persons with those conditions. The committee refers to these conditions as “housing-sensitive conditions” and recommends that high priority be given to conducting research to further explore whether there are health conditions that fall into this category and, if so, what those specific conditions are. The evidence of the impact of housing on HIV/AIDS in individuals experiencing chronic homelessness may serve as a basis for more fully examining this concept.

Cost-Effectiveness of PSH

The committee examined studies that attempted to assess the cost-effectiveness of PSH and found that, at present, there is insufficient evidence to demonstrate that the PSH model saves health care costs or is cost-effective. Unfortunately, the literature on cost-effectiveness of PSH is sparse; few randomized controlled studies have been conducted. Most studies in this regard use a quasi-experimental design. Further, the available studies have not been conducted in a manner that is methodologically aligned with generally accepted health care cost-effectiveness research design. In principle, the most robust scientific evidence to answer the question would come from studies using a randomized design and that cover a comprehensive array of cost and effectiveness measures. Ideally, such studies would allow for constructing the cost-effectiveness ratio to compute the net cost required per unit of quality-adjusted life-years or, at a minimum, provide information on the net cost required for increasing one stably housed day. Unfortunately, there were very few randomized studies and among these, cost measures were incomplete and effectiveness measures scarce.

Importantly, a common question embedded in the evaluation of PSH programs and other health interventions is whether these programs result in a monetary return on investment such as cost savings (Keyes and Galea, 2016). However, PSH was designed with the primary goal of preventing and ending chronic homelessness and not for the purpose of accruing cost savings (USICH, 2015d). The committee believes that evaluations of these programs should a priori be expected to show broad benefits of health and well-being, including keeping individuals experiencing homelessness stably housed. The committee does not believe policy makers and others should expect that permanent supportive housing programs would yield net cost savings, although some cost savings could be identified in specific studies such as those that exclusively focus on persons who are persistently high utilizers of emergency medical services systems.

To address these problems, the committee recommends:

Assessing Individual and Program Characteristics of PSH

There is some evidence that individual characteristics of the people using PSH programs have a modest impact on the outcomes achieved with PSH. For example, persons 50 years of age and older may derive somewhat greater mental health benefits from PSH than younger individuals, although the effectiveness of PSH in reducing homelessness is similar across age groups. The evidence is inconclusive as to whether persons who abuse alcohol or drugs derive housing and health benefits from PSH similar to benefits experienced by persons who do not abuse such substances. The committee found no evidence to support the use of current predictive models to identify individuals who are unlikely to achieve housing stability through PSH programs. Likewise, the committee found a lack of evidence to support the use of assessment tools, notwithstanding their widespread use, to identify individuals who are more likely to have improved outcomes if provided with PSH. The committee’s recommendations below address the need for future research and standards related to individual and program characteristics of PSH.

In addition, the committee’s assessment of the literature indicates that while families who obtain PSH do well—in terms of reducing child behavior problems

and depression and improving parenting competencies (Gewirtz et. al., 2015)—the evidence is not clear that they do better than families who obtain ongoing rental subsidies (Gubits et al., 2015, 2016). Likewise, it is not clear how to target a subgroup that might benefit from case management and additional services linked to housing. There is suggestive evidence that PSH may reduce child placements for some families involved in the child welfare system, but this is also true of subsidies without dedicated services (Gubits et al., 2015). Again, it is not clear how to target this resource (Gewirtz et al., 2015).

Although unaccompanied youth and those who age out of the foster care system are at high risk for adverse health and social outcomes, there is little evidence as to whether PSH might help. PSH has been advocated as an alternative to nursing home care for adults with serious physical needs, but there are no comparative studies. It is plausible that permanent supportive housing would support both housing and health outcomes for high-risk members of all of these populations, but evidence is largely descriptive and ranges from weak to nonexistent. Given this, it is unclear whether other, less intensive interventions might do as well, or how subpopulations who might benefit from PSH should be identified.

Key Policy and Program Barriers

As part of its charge, the committee was asked to identify the “key policy barriers and research gaps associated with developing programs to address the housing and health needs of homeless populations.” Based on its position that PSH holds potential for improving the health outcomes of individuals experiencing homelessness, the committee describes below the key policy and program barriers to bringing PSH and other housing models to scale to meet the needs of those experiencing chronic homelessness.

For example, funding streams and policy regulations for PSH are siloed and often impose substantive restrictions on how the funds may be used. This lack of coordination creates complications for combining or blending funds from different sources, and works against efforts to most efficiently use available funding. Accordingly, the committee recommends the following:

Medicaid is an important funding source for at least a portion of the costs of PSH, particularly in covering the supportive services that people with disabilities or complex health conditions need to achieve housing stability and to access the care necessary to live in community settings.

Prior to the expansion of Medicaid eligibility as part of the Affordable Care Act (ACA), low-income adults were eligible to enroll in Medicaid only if they also met categorical eligibility requirements, meaning that they must be pregnant, a custodial parent of an eligible child, disabled, a senior, or a member of another categorical eligibility group defined by law and state policy. This is still true today in states that have not expanded eligibility as authorized by the ACA. In states that have expanded Medicaid as authorized by the ACA, the primary eligibility criterion is having income lower than 138 percent of the federal poverty line. With this change, a large number of adults who experience homelessness have become eligible for Medicaid based on their incomes, without having to demonstrate that they have qualifying disabilities.

Although federal funds cannot cover rent or the capital costs of constructing or renovating housing, states have options for authorities and programs they can use to include services, including housing-related services, as Medicaid benefits and to obtain federal matching funds for these covered services. States may either request a waiver in order to use Medicaid funds to pay for some housing-related services in PSH and/or use optional state plan benefits to cover these services.

The Centers for Medicare & Medicaid Services has recently acknowledged the important connection between housing and health in an Informational Bulletin on “Coverage of Housing-Related Activities and Services for Individuals with Disabilities” (CMS, 2015). Focusing specifically on individuals experiencing chronic homelessness, individuals with disabilities, and older adults needing long-term support services, the bulletin describes how “certain housing-related activities” can be reimbursed via Medicaid.

States that have pursued optional benefits to facilitate Medicaid reimbursement for services have found these challenging to design and have reported fragmentation in implementation. Obtaining Medicaid waivers to pay for housing-related services has been very challenging for states; some states have had to drop these provisions from waiver proposals or have significantly scaled back or narrowed eligibility for waiver services, among other issues. Other challenges include difficulty in determining how and who can bill for the services provided in supportive housing projects.

In addition, CMS has announced a future expansion of its definition of health-related benefits in its Medicare Advantage plans, which provide extra coverage, such as for vision, hearing, dental, and/or health and wellness programs, to Medicare recipients. In April 2018, CMS released a 2019 Medicare Advantage and Part D Rate Announcement and Call Letter, which announced a reinterpretation of federal statute to expand the scope of the “primarily health-related supplemental benefit” (CMS, 2018). CMS states that under this reinterpretation, the agency would “allow supplemental benefits if they are used to diagnose, prevent, or treat an illness or injury, compensate for physical impairments, act to ameliorate the functional/psychological impact of injuries or health conditions, or reduce avoidable emergency and healthcare utilization.” This is further evidence that the agency has moved in the direction of covering a more integrative approach to

addressing health care needs and that services beyond those traditionally held as health-related, including housing, may improve health outcomes.

Leveraging Medicaid may make it possible to bring PSH to greater scale, and to reach homeless and at-risk persons with housing before chronic homelessness takes a greater toll on their health outcomes and the overuse of public services. To accomplish this, streamlining the approval of waivers that seek to use Medicaid to pay for housing-related services is needed.

As described above, in studies ranging up to 2 years, PSH has been shown to be effective in maintaining housing stability for most people experiencing chronic homelessness. This evidence of the effectiveness of PSH in allowing people to become stably housed indicates that it is possible to reduce chronic homelessness, given sufficient will and a commitment of adequate resources. However, there is a substantial and ongoing unmet need for PSH and a shortfall in the funding used to provide it (Culhane et al., 2002; Sylla et al., 2016). This gap is not filled by the HUD's Continuum of Care and other programs addressing homelessness. In an environment of static or declining discretionary budgets, federal policies should prioritize PSH for persons experiencing chronic homelessness, but not at the expense of downsizing other federal programs that support persons experiencing chronic homelessness. The committee recommends the following:

Finally, the construction of PSH is often hindered by regulatory barriers that make it more difficult and more expensive to address chronic homelessness. The committee reiterates the findings of the Advisory Commission on Regulatory Barriers to Affordable Housing from more than 25 years ago: Local land-use regulations that apply to the siting and construction of new housing present substantive barriers to expanding the availability of affordable housing, including PSH. State and local governments could take action to help reduce unnecessary regulatory

barriers to land use to streamline the development of affordable housing, including single-site PSH. To address another significant barrier to developing additional PSH, HUD could develop model regulations for expediting the siting and construction of single-site PSH. In addition, to eliminate barriers to the use of housing vouchers for scatter-site PSH, federal, state, and local governments could proactively use their anti-discriminatory enforcement authorities and their leverage over the terms of federal grants to incentivize grantees to eliminate barriers that make the programs less effective and efficient.

Overall, based on its assessment, the committee finds that PSH holds potential not only for reducing the number of persons experiencing chronic homelessness but also for improving their health outcomes, although much additional research is needed to determine the effectiveness of PSH and to clarify for whom and in which circumstances it is most beneficial. Chronic homelessness and related health conditions are problems that require an appropriate multidimensional strategy and an ample menu of targeted interventions that are premised on a resolute commitment of resources. More precisely defined and focused research to refine the menu of needed interventions and a materially increased supply of PSH are part of the multidimensional strategy. The committee hopes that this report will stimulate research and federal action to move the field forward and advance efforts to address chronic homelessness and improved health in this country.