We know that for most people who are homeless today, rental assistance or access to affordable housing would end their homelessness. We also know that many people with disabilities can end chronic homelessness and overcome substantial barriers to housing stability if they receive supportive housing. But there is not enough research to guide practitioners and policymakers as they make assumptions about which homeless people with specific characteristics can achieve housing stability and other improved outcomes with rent subsidies or access to affordable housing alone, and which people are unlikely to end homelessness or achieve desired outcomes in other important areas of functioning without access to supportive housing. We do not know enough about how much service support is needed, and for how long, or which specific service strategies are most effective for which groups of homeless people. With limited research about which program models work most effectively for people with varying needs and challenges, decisions about which housing strategies and program options are most appropriate for individuals and communities are too often guided by assumptions and values instead of compelling evidence. Therefore, we recommend the following priorities for continued research:
It is apparent that strategies for eliminating chronic street homelessness are a high priority nationwide (USICH, 2003; USDHHS, 2003; Burt et al., 2004). However, there have been limited efforts to define evidence-based approaches to engaging street homeless individuals in the use of services to assist in coming in off the streets. Research efforts should be directed at this issue.
Research is needed to compare outcomes for homeless people with similar characteristics and needs who receive different well-defined types of housing and services interventions. In particular, more rigorous studies should compare the effectiveness of single-site and scattered-site supportive housing that use both low demand and high demand service strategies. The studies should measure outcomes that include not only housing stability, but also improvements in employment, recovery from addiction, and health status, and examine whether outcomes vary by participant characteristics, including age, gender, race, and types of disabilities. More conclusive evidence about what works best for whom would help guide decisions that currently are too often shaped by value-laden assumptions.
There is a need for extended longitudinal follow-up of clients enrolled in various types of housing and treatment interventions targeted at people who are chronically homeless to gain a better grasp of the long-term effectiveness of the housing and interventions. For example, the typical duration of follow-up in the housing literature is one to two years. Program attrition at that point ranges from about 20 percent to 25 percent (Lipton et al., 2000; Martinez & Burt, 2006). Lipton et al. (2000) found that at the five-year mark, only 50 percent were still in supportive housing. More information is needed on people who move out (e.g., why they move out, where they go, whether they become homeless again).
There is a need to better understand the effectiveness of specific strategies such as housing first versus treatment first for engaging the most disabled homeless people living on the streets in the use of services and housing. While this is clearly a high priority among policymakers and many practitioners, investment in research that would define evidence-based practice in this area has been limited, and we need to better understand the characteristics and needs of those who have been unable or unwilling to enter available housing or residential programs as well as factors that contribute to motivation and readiness to change.
Outcomes in studies of the impact of housing and treatment services should be broadened to include cost outcomes, family relationships and child welfare, incarceration and public safety, high-risk behaviors and communicable disease, psychiatric symptoms, recovery from substance abuse, and social inclusion.