Effectiveness of interventions to reduce homelessness. A systematic review
On the effectiveness of housing programs and case management to improve housing stability and reduce homelessness among people who are homeless or at-risk of becoming homeless.
- Issued/Revised: Desember 2016
- By: Folkehelseinstituttet
Despite work to prevent and reduce homelessness over the last 15 years, the number of homeless persons in Norway has remained stable since the first mapping of homelessness was published in 1997. We conducted a systematic review on the effectiveness of housing programs and case management to improve housing stability and reduce homelessness among people who are homeless or at-risk of becoming homeless.
The results of the review are based on evidence from 43 randomized controlled studies. The key findings show that high intensity case management is probably better than usual services at reducing the number of people who are homeless. The program called Housing First is probably better than usual services at reducing homelessness, improving housing stability and increasing the amount of time in housing. Furthermore, the following interventions may be better than usual services at reducing homelessness and/or improving housing stability:
- Critical time intervention
- Abstinence-contingent housing
- Non-abstinence-contingent housing with high intensity case management
- Housing vouchers
- Residential treatment
It seems that many of these interventions may have similar beneficial effects, and it is unclear which of these is best with respect to reducing homelessness and increasing housing stability.
We found that a range of different housing programs and case management interventions appear to improve housing stability and reduce homelessness compared to usual services. The findings showed no indication of housing programs or case management resulting in poorer outcomes for homeless or at-risk individuals than usual services.
Preventing homelessness has been a priority for the Norwegian State Housing Bank (Husbanken) since 1999. However, the number of homeless persons in Norway has remained between 5000 and 6500 since the first mapping of homelessness was published in 1997. The current National Strategy for housing and support services has three overarching goals: 1) Everyone should have a good place to live; 2) Everyone with a need for services will receive assistance in managing their living arrangement, and; 3) Public efforts shall be comprehensive and effective. The aim of this report is to contribute evidence for which to base decisions on how best to meet these goals.
To identify, appraise and summarize the evidence on the effectiveness of housing programs and case management to improve housing stability and reduce homelessness among people who are homeless or at-risk of becoming homeless.
We conducted a systematic review in accordance with the Knowledge Centre’s handbook. We systematically searched for literature in relevant databases and conducted a grey literature search which was last updated in January 2016. Randomized controlled trials that included individuals who were already, or at-risk of becoming, homeless were included if they examined the effectiveness of relevant interventions on homelessness or housing stability. There were no limitations regarding language, country or time. Two reviewers screened 2918 abstracts and titles for inclusion. They read potentially relevant references in full, and included relevant studies in the review. We pooled the results and conducted meta-analyses when possible. Our certainty in the primary outcomes was assessed using the Grading of Recommendations Assessment, Development, and Evaluation for effectiveness approach (GRADE).
We included 43 relevant studies (described in 78 publications) that examined the effectiveness of housing programs and/or case management services on homelessness and/or housing stability. The results are summarized below. Briefly, we found that the included interventions performed better than the usual services in all comparisons. However, certainty in the findings varied from very low to moderate. Most of the studies were assessed as having high risk of bias due to poor reporting, lack of blinding, or poor randomization and/or allocation concealment of participants.
Case management is a process where clients are assigned case managers who assess, plan and facilitate access to health and social services necessary for the client’s recovery. The intensity of these services can vary. One specific model is Critical time intervention, which is based on the same principles, but offered in three three-month periods that decrease in intensity.
High intensity case management compared to usual services has generally more positive effects: It probably reduces the number of individuals who are homeless after 12-18 months by almost half (RR=0.59, 96%CI=0.41 to 0.87) (moderate certainty evidence); It may increase the number of people living in stable housing after 12-18 months and reduce the number of days an individual spends homeless (low certainty evidence), however; it may have no effect on the number of individuals who experience some homelessness during a two year period (low certainty evidence). When compared to low intensity case management, it may have little or no effect on time spent in stable housing (low certainty evidence).
Critical time intervention compared to usual services may 1) have no effect on the number of people who experience homelessness, 2) lead to fewer days spent homeless, 3) lead to more days spent not homeless and, 4) reduce the amount of time it takes to move from shelter to independent housing (low certainty evidence).
Abstinence-contingent housing programs
Abstinence-contingent housing is housing provided with the expectation that residents will remain sober. The results showed that abstinence-contingent housing may lead to fewer days spent homeless, compared with usual services (low certainty evidence).
Non-abstinence-contingent housing programs
Non-abstinence-contingent housing is housing provided with no expectations regarding sobriety of residents. Housing First is the name of one specific non-abstinence-contingent housing program. When compared to usual services Housing First probably reduces the number of days spent homeless (MD=-62.5, 95%CI=-86.86, -38.14) and increases the number of days in stable housing (MD=110.1, 95%CI93.05, 127.15) (moderate certainty evidence). In addition, it may increase the number of people placed in permanent housing after 20 months (low certainty evidence).
Non-abstinence-contingent housing programs (not specified as Housing First) in combination with high intensity case management may reduce homelessness, compared to usual services (low certainty evidence). Group living arrangements may be better than individual apartments at reducing homelessness (low certainty evidence).
Housing vouchers with case management
Housing vouchers is a housing allowance given to certain groups of people who qualify. The results showed that it may reduce homelessness and improve housing stability, compared with usual services or case management (low certainty evidence).
Residential treatment with case management
Residential treatment is a type of housing offered to clients who also need treatment for mental illness or substance abuse. We found that it may reduce homelessness and improve housing stability, compared with usual services (low certainty evidence).
The identified studies include a good representation of the typical populations who struggle with housing stability (adults with mental illness and/or substance abuse), as well as some relatively smaller portions of the homeless population (families, youth, recently released criminal offenders). Collectively, the included studies examined all of the interventions that were identified in the project protocol. All comparison conditions, both usual services and other, are considered active interventions. All of the studies addressed the primary outcomes (homelessness and housing stability) and many of the studies also examined secondary outcomes. Altough most of the studies were from the USA, we have few reservations about the transferability of the review findings, because the results were consistent across contexts (including a study from Scandinavia). The high risk of bias in most of the studies is mainly due to poor reporting of methods and/or lack of blinding. The latter issue is difficult to address given the nature of the programs.
We found that a range of housing programs and case management interventions appear to reduce homelessness and improve housing stability, compared to usual services. The findings showed no indication of housing programs or case management resulting in poorer outcomes for homeless or at-risk individuals than usual services.
Aside from a general need for better conducted and reported studies, there are specific gaps in the research. We identified research gaps concerning: 1) Disadvantaged youth; 2) Abstinence-contingent housing with case management or day treatment; 3) Non-abstinence contingent housing, specifically different living arrangements (group vs independent living); 4) Housing First compared to interventions other than usual services, and; 5) All interventions from contexts other than the USA.