Toward Understanding Homelessness: The 2007 National Symposium on Homelessness Research. People Who Experience Long-Term Homelessness: Characteristics and Interventions. Housing Interventions


The social disability that often accompanies severe and persistent mental illness can interfere with the ability to sustain independent living. In recognition of this fact, supportive housing has evolved over the past two decades as a preferred housing approach for people with severe and persistent mental illness (Rog, 2004) and is now viewed as a best practice for ending chronic homelessness. Broadly defined, supportive housing is independent housing in the community coupled with support services (Rog, 2004). People who have been living on the streets or in shelters for long periods of time often need additional services to stabilize a psychiatric or substance abuse problem that, if left untreated, may inhibit residential stability. Moreover, chronically homeless individuals may find it extremely difficult to engage in a process of treatment without being housed. There is mounting evidence that the combination of housing and treatment is effective in facilitating both housing stability and treatment retention (Burt & Anderson, 2005) and that this approach is superior to treatment alone (Rosenheck et al., 2003). Housing and services combined appear to provide a synergy that helps people who have experienced chronic homelessness to achieve more stable and independent lives.

As defined by HUDs Homeless Assistance Programs, supportive housing includes both transitional and permanent supportive housing programs, as well as Safe Havens, which can function as either permanent or transitional housing. These programs are targeted to homeless individuals with disabilities, and many grants awarded in recent years are specifically targeted to projects that serve chronically homeless people. At this time only homeless people who are coming from the streets or emergency shelters are eligible to move into permanent supportive housing that is funded through HUDs Homeless Assistance Programs, although supportive housing funded from other sources may have different eligibility provisions. Homeless people with disabilities and homeless families may be eligible for transitional housing. The Department of Veterans Affairs (VA) also funds transitional housing programs for homeless veterans, as well as supportive services coupled with HUD-funded rental assistance, in a program called HUD-VA Supported Housing or HUD-VASH. Other federal, state, and local government programs are also used to fund transitional or permanent supportive and affordable housing for people who are homeless or at risk of homelessness and for low-income people with disabilities or other special needs, including targeted programs that fund housing for adults with HIV/AIDS (often with co-occurring mental health and/or substance use problems).

Most frequently, research has focused on program models that combine housing and services that have been developed for adults with serious mental illness who are homeless or at risk of homelessness, and often study participants include people who also have co-occurring substance use problems or other health conditions. There is also some research that focuses on housing for adults with HIV/AIDS and housing for those with serious long-term problems with substance use, particularly a group that has been described as chronic public inebriates.

Increasingly, supportive housing programs have been adapted specifically to improve access and effectiveness for people who have experienced chronic homelessness. The housing models that are most directly relevant to the needs of chronically homeless people include transitional housing, permanent supportive housing, and Safe Havens. First, we describe these housing models and review their similarities and differences. Then we present evidence on their efficacy.

Common Characteristics of Supportive Housing Models

Supportive housing has become a key program model for homeless assistance and mental health systems throughout the country. Supportive housing can be provided in a single-site model where all or most of the units in an apartment or SRO building serve formerly homeless people and many of the services are provided on site; in a scattered-site model where tenants access rent-subsidized units on the open market and services are coordinated by case managers; and a hybrid model in which a single site mixes supportive housing with regular affordable housing (Corporation for Supportive Housing, 2004; Burt, 2005). Transitional and permanent supportive housing share the following characteristics:

  • Appropriate targeting.  Housing is targeted to people who are homeless or are at risk of homelessness and who are experiencing mental illness or other chronic health conditions or challenges that would affect their ability to achieve residential stability.
  • Affordability.  Tenants usually pay no more that 30-50 percent of their income in rent.
  • Range of services to meet a diversity of needs.  Services generally include coordinated case management, life skills, help in setting up a household, and tenant advocacy. Health and mental health treatment, substance use management and recovery, peer support, vocational and employment services, money management, and other supports may be provided directly or by facilitating linkages to appropriate community services.

Differences in Supportive Housing Models

Supportive housing models vary across a number of dimensions. Generally, variation along these dimensions exists between transitional and permanent models, although it often exists within models as well.

Housing first versus requiring housing readiness. The housing first model is generally defined as a program that places people directly into affordable housing without requiring that tenants be housing ready prior to entry. High-threshold housing readiness admission criteria require, for example, that prospective tenants demonstrate several months of sobriety, basic living skills and personal hygiene, and a high level of motivation to participate in treatment or case management services and to manage symptoms of mental illness. A known limitation of the housing readiness approach is that a majority of those who are chronically homeless, even among those who have participated in treatment or transitional programs that are intended to prepare them for housing, may not be able to meet these demands (Barrow & Soto, 2000; Barrow, Soto, & Cordova, 2004; Kertesz et al., 2006). Safe Havens use a housing first approach, and a growing number of permanent supportive housing programs are adjusting admission criteria to move toward a housing first approach (Burt et al., 2004; Burt, 2005; Tsemberis, 1999), although programs vary widely on this dimension.

The extent to which a low demand environment is created. Often implemented as part of a housing first model, a low demand approach does not place any requirements on a tenant that are outside of the normal conditions of tenancy, including paying the rent, not destroying property, and refraining from behavior that would harm other tenants. Housing programs that utilize a low demand approach strike a balance between helping individual tenants  even the most troubled  achieve housing stability, and enforcing rules that prohibit illegal activity and protect the safety of other tenants and their neighbors. This philosophy extends to the delivery of services in housing. Although participation is certainly encouraged in low demand programs, services are not mandatory and instead are based on consumer choice.

Some of the characteristics of housing-first/low demand models, in contrast to high demand housing models, are described in Exhibit 1. There is a wide spectrum of what constitutes low demand. For example, some programs may require a low level of service participation (e.g., one or two meetings with a case manager every month), but not link that participation directly to tenants ability to keep their housing. A low demand approach is used in Safe Havens as well as in many permanent supportive housing programs designed for people who are chronically homeless. There can be a range of approaches in permanent supportive housing (Burt, 2005; Lipton et al., 2000; Tsemberis, Gulcur, & Nakae, 2004). Transitional housing tends to be more structured and requires participation in treatment or work programs, regular appointments with case managers, and continued efforts to find permanent housing.

Intensity/richness of services. This dimension refers to the breadth and depth of services available to program participants and the staff/client ratios. Safe Havens tend to have a very rich set of services and low staff/client ratios, in part because of the small size of these programs. In permanent supportive housing and transitional housing models, service intensity can vary greatly from project to project depending on the target population, program goals, and service financing.

Permanency of housing. This dimension refers to whether participants/tenants may stay in housing indefinitely or whether they are encouraged or required to leave after a certain period of time. The goal of Safe Havens and transitional housing is to eventually move people into permanent housing in the community. Safe Havens, however, may function as either transitional or permanent housing and are generally flexible about letting participants stay until they have found other options. In contrast, transitional housing models usually have stricter time limits. For example, HUD-funded transitional housing programs generally expect residents to move within 24 months. Some transitional housing programs offer tenants the opportunity to transition in place, meaning that tenants may remain in the same housing unit after their participation in a transitional housing program ends, as they assume responsibility for paying rent, and in some cases qualify for other types of ongoing rental assistance from other housing programs. Permanent supportive housing does not have time limits or requirements that tenants move to other settings. Permanent supportive housing programs may allow tenants with the most severe mental health or substance use disorders to maintain a home they can return to after a temporary hospitalization or a stay in a treatment facility.

Exhibit 1 outlines major differences between housing-first/low demand and high demand supportive housing models, elaborating on what has been discussed above. The most well-known, rigorously evaluated and widely replicated housing first / low demand program is Pathways to Housing (Tsemberis et al., 2004), which uses a scattered site model. Other site-based housing first / low demand programs for chronically homeless adults have been described, including Seattles Lyon Building and 1811 Eastlake projects, Californias Health, Housing and Integrated Services Network, and San Franciscos Direct Access to Housing Program. As shown in Exhibit 1, these programs share many characteristics but there is some variability in the implementation of these approaches.

Research and published reports often highlight the differences between these two models, but in practice many supportive housing projects incorporate elements of both housing first/low demand and high demand approaches. For example, a housing program may target people who have been living on the streets for many years, but may require that they first engage in case management services for a period before being offered housing. Some programs may require a low level of service participation (e.g., one or two meetings with a case manager every month), but not link that participation directly to tenants ability to keep their housing. Some programs offer tenants opportunities for repeated short stays in interim or transitional housing, which may require that tenants leave the housing if they are disruptive or use alcohol or drugs on site, but allow tenants to return to housing again when they are willing to comply with program rules, and move on to more permanent housing as they achieve greater stability. Low demand housing programs often use a variety of strategies to assertively engage tenants in supportive services and strongly encourage participation, particularly when a tenants behavior is disruptive to others or may lead to eviction, or when there are concerns that symptoms or problems related to health, mental health, or substance abuse are worsening.

Efficacy of Housing Interventions

Transitional housing. Transitional housing programs funded by HUD serve more than 20,000 chronically homeless people each year, approximately 20 percent of those served by these programs. Most of HUDs transitional housing programs primarily serve homeless families or adults who have been homeless for shorter periods of time (Mark Johnston, personal communication, November 2006). To date, very little information is available on the efficacy of this program model for chronically homeless adults. It is not presently known, for example, how many chronically homeless people move from transitional housing to other stable permanent housing. Information is also lacking on the characteristics of those for whom this program model is successful in contrast to those for whom this model has failed. Nearly all of the research on transitional housing has focused on programs that serve homeless families.

While most transitional housing programs primarily serve people who are not chronically homeless, some transitional housing programs have been adapted to engage chronically homeless people who are ambivalent about services and pique their interest in seeking housing. Two transitions are involved in these programs. The first transition is from the streets or emergency shelters into the program, and the second transition is from the program into permanent housing. In settings where permanent supportive housing has high threshold housing readiness requirements, transitional housing programs may provide opportunities for people who are chronically homeless to demonstrate that they are ready to leave the streets and undergo a period of documented sobriety and participation in supportive services in preparation for permanent housing.

Because transitional housing programs are designed to help homeless people move toward more permanent housing, they often require residents to attend treatment or work programs, meet regularly with case managers, and make progress toward achieving goals related to housing readiness. While this structure may be effective for some people who are chronically homeless, others may be unable or unwilling to accommodate to these demands and requirements.

Some transitional housing programs that have been specifically designed or adapted for people who are chronically homeless have incorporated low demand program models that use program strategies including:

  • assertive but patient engagement to overcome barriers resulting from mistrust, isolation, and the symptoms of mental illness or addiction;
  • identification of participants unmet needs, preferences, and goals;
  • establishment of trusting relationships, which often begins by providing concrete support for basic needs (food, clothing, etc.);
  • training or coaching in basic living skills and personal hygiene;
  • mental health and substance abuse treatment services (provided directly or through close linkages to community services);
  • allowing a series of short stays or moves between programs that offer varying levels of support and requirements for participation and sobriety;
  • assistance with accessing benefits or income; and
  • encouragement and help to find and meet eligibility requirements for permanent housing (Barrow & Soto, 1996; Barrow & Soto, 2000).

The intention of transitional programs that use this approach is to build trusting relationships and engage even the most chronically homeless individuals in the service system, thus facilitating access to needed care and treatment and preparation for permanent housing (Barrow, Soto, & Cordova, 2004). Transitional housing has also been used as a technique to increase the effectiveness of substance abuse treatment programs, even when housing is not conditional upon abstinence (Kertesz, 2006). Transitional housing programs have limited effectiveness in helping participants achieve housing stability when permanent housing programs have complex and stigmatizing admissions procedures and program requirements that include evidence of sustained sobriety or a willingness to participate in treatment or other structured activities as a condition of tenancy (Barrow & Soto, 2000; Barrow, Soto, & Cordova, 2004; Kertesz, 2006).

Permanent supportive housing. Permanent supportive housing has gained considerable attention from practitioners and policymakers in the last 1015 years, in part because of numerous research studies demonstrating its effectiveness in increasing housing stability (Barrow, Soto, & Cordova, 2004; Rog, 2004; Lipton et al., 2000; Shern et al., 2000; Tsemberis & Eisenberg, 2000) and decreasing shelter use, incarceration, inpatient hospital stays, and visits to the emergency room (Culhane, 2002; Martinez & Burt, 2006; Rosenheck et al., 2003).

Permanent supportive housing is the combination of permanent, affordable housing with supportive services aimed at helping residents maintain housing stability. While not all such programs are the same, the shared components that are most likely to distinguish permanent supportive housing from transitional housing include the following:

  • Voluntary services. Participation in services is usually not a condition of ongoing tenancy in permanent supportive housing.[2]
  • Tenants hold a lease. The tenant has a lease or similar form of occupancy agreement so as not to set a limit on the length of time a person can stay in housing.
  • Systems integration. A working partnership exists between the service providers, property owners or managers, and/or housing subsidy programs.

The New Freedom Commission on Mental Health (2003) recommended the creation of 150,000 units of permanent supportive housing to end chronic homelessness among people with mental illnesses and their families, and HUD established the goal of creating 40,000 new units of permanent supportive housing for chronically homeless people during the five-year period from 2005 to 2009. As states and communities across the nation developed their own plans to end homelessness, they adopted ambitious goals for creating additional affordable and supportive housing, including (as of November 2006) a total of 80,000 units of permanent supportive housing (NAEH, 2006b).

From 1996 to 2005 the number of units of permanent supportive housing for homeless people in the U.S. nearly doubled, from 114,000 to 208,700 (HUD, 2007). Between 2002 and 2006, approximately 37,500 units of permanent supportive housing were created using funding provided through HUDs McKinney-Vento Homeless Assistance Grants Programs. Eligibility for this housing is restricted to homeless persons with disabilities, which may include mental illness or substance abuse.[3]  In recent years new supportive housing created through this program has been targeted to people who are chronically homeless.

Permanent supportive housing is also funded from other sources (including other mainstream federal and state housing programs as well as targeted programs funded by states and local governments). Some of this supportive housing, particularly housing funded by state and local mental health authorities and mainstream housing programs, serves people with disabilities who are homeless or at risk of homelessness, but not chronically homeless. Reflecting this variability in eligibility and target populations, survey results from a range of states and communities indicate that about a third of the permanent supportive housing units are occupied by people formerly chronically homeless (Burt, 2005).

  1. Housing stability outcomes. Evaluations of permanent supportive housing have shown retention rates in the first year of 7585 percent, even among chronically homeless adults with the most severe mental health and substance use disorders (Barrow, Soto, & Cordova, 2004; Burt et al., 2004; Martinez & Burt, 2006; Wong et al., 2006). About three-quarters of those who enter supportive housing stay for at least two years, and about half are still living there after three to five years (Wong et al., 2006; Lipton et al., 2000). Variability in retention rates reflects several factors, including characteristics of supportive housing tenants, housing, program structure, expectations, and requirements. Because most permanent supportive housing offers tenants the opportunity to return to a permanent housing unit (either the same unit or another apartment) after short stays in a hospital or treatment setting, and some chronically homeless people may return to spend time in shelters or on the streets for a few days as they become accustomed to living in housing, some researchers have also measured housing stability in terms of reductions in the number of days of homelessness or increases in the number of days in housing.

    The likelihood of moving out  often into unstable living arrangements  seems to be greatest during the first few months after tenants move into supportive housing, especially for residents who are living in supportive housing programs with a high degree of program structure and tenant expectations (Lipton et al., 2000). Older age seems to be associated with longer tenure in supportive housing. In some evaluations that consider a range of supportive housing program models, factors related to substance use, including a history of substance abuse and/or active substance use are associated with lower rates of housing stability, especially for homeless people who have moved into highly structured settings that are more likely to evict tenants for relapse in the use of alcohol or other drugs (Lipton et al., 2000; Wong et al., 2006).

  2. Outcomes on service utilization and cost. Evaluations of permanent supportive housing have also attempted to measure changes in patterns of service utilization. Researchers from the University of Pennsylvania conducted a major study of the costs and utilization of public services, including hospitalizations and other Medicaid services, by more than 4,500 homeless adults with serious mental illness in New York City. The study included extensive regression analysis to determine both the costs of services used by homeless persons and the reductions that were attributable to placement in supportive housing. They found significant reductions in the total number of days that tenants spent in shelters (61 percent), inpatient psychiatric hospitals (61 percent), public hospitals (21 percent), VA inpatient hospitals (24 percent), prisons (85 percent), and jails (38 percent). While days in Medicaid-reimbursed inpatient services went down by 24 percent, the number of days of Medicaid-reimbursed outpatient services actually increased by 76 percent, which is probably a result of tenants having better access to more appropriate and preventive healthcare services while housed. Placement into supportive housing was associated with a reduction in services use of $16,281 per housing unit per year, and $14,413 of the service reduction savings resulted from the decrease in emergency and inpatient health and mental health services. The reduced costs associated with these changes in service utilization, when measured on a per diem basis, cover 95 percent of the cost of developing and operating supportive housing (Culhane, Metraux, & Hadley, 2002).

    Other studies have shown similar findings:

    • A study of two permanent supportive housing projects in San Francisco, targeted specifically to chronically homeless individuals, found significant reductions in the utilization of hospital emergency room and inpatient care. Study participants were 236 homeless adults who had been living on the streets or in emergency shelter for extended periods of time, a large majority (75 percent) of whom had co-occurring mental illness and substance abuse disorders. The study compared service utilization during the 12-month period before and after homeless persons moved into supportive housing. The researchers found a 57 percent reduction in the total number of emergency room visits for this group and a 45 percent reduction in the total number of inpatient admissions (Martinez & Burt, 2006).
    • A study of the Connecticut Supportive Housing Demonstration Project also showed a reduction in Medicaid-reimbursed inpatient services while utilization of other services remained stable or increased (Arthur Andersen LLP, 1999).
    • Total medical charges for residents in two Minnesota supportive housing programs for chronically homeless persons addicted to alcohol declined by 32 percent to 68 percent in comparisons between the year before and the year after program entry. Medical and hospital visits declined, particularly for visits related to alcohol or injury, and the median number of detox visits declined by 90 percent (Thornquist et al., 2002).
    • Findings from Denvers Housing First Collaborative showed that utilization of emergency room services decreased by 34 percent in the two years after chronically homeless people entered the program, while the number of nights of inpatient hospitalization declined by more than 80 percent. Costs for outpatient care increased by 50 percent, resulting in a 45 percent net reduction in total health costs (Perlman & Parvensky, 2006).
    • A random assignment evaluation of the HUD-VASH program found less robust reductions in service utilization. Overall the HUD-VASH program was 15 percent more costly than standard care  an average of $45 more for every additional day participants were housed. The program produced savings attributable to participants decreased use of the shelter system and some changes in patterns of utilization of health services, but participants increased their utilization of mental health services, including homeless case management services provided as part of the program. Other positive outcomes for program group members included greater satisfaction with housing, higher housing quality, larger social networks, and reduced problems related to the use of alcohol or other drugs (Rosenheck et al., 2003; Cheng et al., in press).
  3. Other health outcomes, Research on the impact of supportive housing on the health and well-being of chronically homeless people with disabilities has been limited, although some improvements in health may be inferred from the significant reductions in hospitalizations and emergency room visits that have been reported. To date most of the research on supportive housing has measured housing outcomes and utilization of other public services, while there has been little investigation of other impacts such as changes in psychiatric symptomatology or the use of alcohol and drugs. These issues require further study and evaluation. Compelling findings are emerging from research about the relationship between housing and HIV/AIDS, for which measurements of viral load and CD4 cell counts provide objective measures of improved health outcomes. Among homeless people with HIV/AIDS, access to housing is associated with significant improvements in entry into and retention in appropriate medical care, significantly reduced viral load (increased viral suppression), and increased CD4 count (Schubert, 2006) as well as reductions in high-risk sex and drug behaviors that are associated with transmitting HIV to others (Aidala, 2006; Schubert & Botein, 2006).
  4. How do outcomes differ among program models and participants? Practitioners and policymakers want to know what models of housing and services work best  and for whom. While findings are far from definitive, available research provides some important clues.

    Importantly, housing retention appears to be greatest when housing is combined with services, regardless of the specific model of housing (Lipton et al., 2000; Rog, 2004; Siegel et al., 2006). However, the duration and intensity of services required to sustain housing requires further study and evaluation.

    It appears that consumers prefer to live in housing that offers opportunities for integration and independence, while service providers more often believe that staffed group homes or other housing with a higher level of support would be more appropriate for consumers with greater clinical vulnerability. Goldfinger et al. (1999) examined the influence of staffed group living sites versus individual apartments for formerly homeless people with mental illness in a random assignment study. Individuals assigned to independent apartments experienced a greater number of days homeless compared to those in staffed group homes  among members of minority groups only. Substance abuse was the strongest individual-level predictor of days homeless. Individuals whom clinicians determined would do best with group living experienced more days homeless, regardless of the type of housing they received. Findings suggest that housing type should be geared to the clinical and social characteristics of consumers in order to achieve optimal housing outcomes. Consumers living in independent apartments report greater satisfaction with their housing and autonomy, but Siegel et al. (2006) found that they also experience greater feelings of isolation when compared to consumers who live in site-based supportive housing with more intensive services.

    There is also evidence that the manner in which housing and services are organized has a significant impact on housing tenure. In a random assignment study of integrated (case management and housing services provided by teams within a single agency) versus parallel housing services (case management services provided by mobile assertive community treatment teams and housing by routine community-based landlords) for adults with severe mental illness who were at high risk for homelessness, McHugo et al. (2004) found that integrated housing services led to more stable housing and life satisfaction compared to parallel housing services, particularly for male participants.

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