Toward Understanding Homelessness: The 2007 National Symposium on Homelessness Research. Historical and Contextual Influences on the U.S. Response to Contemporary Homelessness. Services and Treatments


The Case for Evidence-Based Practices and Translational Research

As the homeless system of service continues to identify subgroups within the population, one correlate will be the need to identify specific services that are appropriate, responsive to their needs, and show results. These standards are some of the most serious challenges the field of homelessness services faces. As is evident in other papers in the Symposium, particularly those focused on subgroups and effective service responses, the accumulation of a compelling literature on service effectiveness is not substantial. The declaration that we know what works is often based on the popularity of an approach, ex cathedra assertions, or the concept of truthiness: the quality of preferring concepts or facts one wishes to be true, rather than concepts or facts known to be true (American Dialect Society, 2006). When challenged to embrace the prevailing concept of evidence-based practices, both providers and homelessness researchers are apt to give the concept a pass, noting the difficulty of rigorous study designs, the crisis nature of homelessness, and the suppression of innovation. These are serious considerations, but fields such as medicine have embraced evidence-based approaches without regarding these considerations as impediments.

As the country re-engages with the concept of health care coverage for the uninsured, the idea that covered services must be evidence based or otherwise demonstrably effective is a fundamental premise. Since health care coverage for homeless persons is often put forth as the twin panacea with affordable housing, the field of homeless services must be prepared to demonstrate that a core of treatments and services meets the standards of evidence based or demonstrably effective. A failure to do so risks disenfranchising homeless persons from full participation if health care coverage were extended to the uninsured in the future.

Although evidence based is only one of the standards that can be invoked to attest to effectiveness, it is useful to examine its applicability to homelessness treatments and services. Leff (2002) defines evidence-based practices as practices that have been tested employing specified scientific methods and shown to be safe [acknowledging side effects], efficacious, and effective for most persons with a particular disorder or problem. Leff points out that services may coincide with treatment outcomes, both positive and negative, but that it is impossible to tell if the services produced the result or if it was the result of some other factor. Experiments, evaluations, peer-reviewed journal articles, practice guidelines, and voluntary review organizations contribute to reducing this noise and help determine if specific treatment procedures produce the desired outcome. More fields within health and human services are asking about acceptable evidence for the services being delivered. The intent is to ensure that the services are safe and have the intended effect. Standards that have been used in the past  professional judgment, experience, teaching, and anecdote  do not carry these assurances.

Several housing and treatment interventions hold considerable promise for demonstrable effectiveness. At least one behavioral health treatment  Critical Time Intervention (Herman et al., in press)  has been affirmed to be evidence based by SAMHSAs National Registry of Evidence-Based Programs and Practices (SAMHSA, 2007;[5]  Also, many of the primary care treatments, albeit adapted to homeless clients, fall within the family of evidence-based medicine. Two other services that are receiving considerable attention, primarily in connection with the focus on chronic homelessness, are assertive community treatment (ACT) case management, and housing first. Both show promise as effective services.

ACT and Housing First Interventions and Fidelity to Models

ACT, described in detail in other papers for this Symposium, is a unique approach characterized by intensive, in vivo services delivered by an interdisciplinary team, overseen by a physician and nurse. The services are treatment oriented but include some linkage with other services and client advocacy. Caseloads are small, and the interdisciplinary team adjusts the intensity of its work with the client over long periods based on how the client is doing.

Systematic reviews of case management interventions (Holloway & Carson, 2001) and their applicability to homelessness (Morse, 1999) conclude that experimental and evaluation evidence is particularly strong for ACT. In addition to its superior clinical outcomes, ACT has been shown to:

  • reduce service costs among high users of mental health services (Chandler & Spicer, 2002),
  • engage and retain clients better than other case management approaches (Herinckx et al., 1997),
  • help homeless consumers sustain treatment gains when transferred to another case management approach (Rosenheck & Dennis, 2001), and
  • effectively address co-occurring substance abuse and mental illness (Drake et al., 1998).

ACTs positive effects and its applicability to behavioral health problems of homeless persons make it a key ingredient in our services armamentarium. While the evidence is supportive, it is important to note that the services need to be delivered with fidelity to the documented intervention. ACT is sufficiently well developed to have training programs, toolkits, and measures of fidelity (see Allness & Knoedler, 2003; SAMHSA, 2003b).

Housing first is also described in detail in other papers for this Symposium. As originally described by Tsemberis (e.g., Tsemberis et al., 2004), this intervention allows a homeless person to be placed directly into a permanent housing opportunity that includes the availability of intensive treatment and support. Tsemberis found superior housing stability for those in housing first settings offering these key components.

The field has moved somewhat rapidly to adopt housing first as the preferred housing intervention, particularly in response to ending chronic homelessness, and it is widely implemented for both individuals and families (NAEH, 2006a). The model of implementation of housing first in multiple sites is not always clear, particularly whether it includes the key components itemized by Tsemberis or is simply a label for housing locations other than overnight emergency shelter.

Thus, while the interventions of ACT and housing first show promise, their implementation in practice identifies an additional feature of importance: fidelity to the model. Just as a health practitioner would not freely depart from the procedures in a medical protocol that contribute to its effectiveness, a homeless service should be implemented consistent with the procedures that contributed to its effectiveness. This is not meant to discourage innovations or local adaptations. But it is an explicit caution that the greater the departure from the model, the less a claim can be made that the effective intervention is being delivered. For the homeless service field to advance in the development of a cadre of effective services, there should be a more explicit recognition of the steps needed to ensure they are effective.

Ensuring Interventions Are Appropriate

Agree on the key components of the intervention. Bassuk and Geller (2006) have noted that housing first approaches for individuals and families are not necessarily implemented with a service component. Teague and colleagues (1998) found that in more than 50 applications of ACT, many differed significantly in the key components of this intervention. We can only move to evidence-based standards if there is agreement about the intervention being implemented and its critical components.

Evaluate the evidence. Leff indicates there are professional organizations, such as the Campbell Collaborative in the U.S., that employ documented procedures to determine if a practice receives an imprimatur as being evidence based. The NREPP cited above uses 16 criteria to evaluate and categorize the evidence base of programs (SAMHSA, 2006). Whatever evaluation methods are used, the quality of the evidence must be subjected to systematic examination to determine if an intervention causes the desired changes and is safe.

Address gaps. If the review of the evidence suggests gaps or barriers that impede the designation of evidence based (e.g., insufficient numbers of random assignment studies, too few participants to be conclusive), agreement is needed to invest in the necessary work to address the gaps and barriers. The community committed to correcting homelessness must move to incorporate more rigorous standards ensuring their interventions are solidly grounded, effective, and safe.

Translational Research

A relevant tool for ensuring that services are effective is translational research. Translational research is concerned with improving the movement of knowledge developed in basic research environments to clinical practice, with equal opportunity for movement from clinical practice to research (Marincola, 2003). This focus emerged primarily from recognition of delays and failures in the incorporation of research on effective treatment into service delivery. To ensure that the investment in research is yielding changes in treatment practices, the National Institutes of Health have included translational research as a key feature of the roadmap for accelerating a partnership between research and clinical medicine (Zerhouni, 2003).

Exhibit 5
System Component:
Services and Treatments
Significant development:
  • Evidence based interventions with ACT and housing first as potential candidates


  • Ability to deliver services of proven effectiveness


  • Thoroughness and quality of research findings not yet sufficient
  • Transferring knowledge successfully to the service provider

Future directions:

  • Adopt a course of action to accumulate sufficient evidence
  • Borrow knowledge transfer principles from translational research

Translational activities do not necessarily wait for the same types of validation processes that characterize evidence-based practice. They may function and succeed best in dynamic environments and specialized centers where research/evaluation and clinical teams operate together, using checks and balances, internal review boards, and ethics guidelines. The goals are to ensure treatment protocols are being followed and client safety is continuously monitored while innovations are being tried.

The relevance of the translational research concept to homelessness is twofold. First, the concept directs us to be receptive to innovations homeless service providers are developing with their clients. These are opportunities to identify more effective and efficient services. Providers must be more willing to view themselves as the specialized centers noted above, where innovations are accompanied by evaluation, however basic.

The second reason translational research is relevant relates to the barriers we face in trying to ensure practitioners can incorporate these practices. After nearly a decade of innovative homeless service development, Manderscheid and Rosenstein (1992) noted that new treatment models in homelessness were not penetrating to the local level. Even today, resources, time, and attitudes do not always facilitate adoption of new practices. The mechanisms by which service providers can learn about new service developments could also function much better. Whether the mechanisms are technical assistance offerings, reports, toolkits, courses, or conferences, they are not always designed with translational research principles in mind.

Respectful relationships, particularly avoiding top-down and mandated approaches, have been a key ingredient, one consistently underscored in the Translating Research into Practice (TRIP) Initiative of the Agency for Healthcare Research and Quality (2001). Such features as factoring in adult learning, using multiple methods of sharing and disseminating the knowledge, developing an implementation plan in lockstep with the knowledge transfer, and trying to ensure a receptive home environment have also been used for effective transfer (Davis & Taylor-Vaisey, 1997).

As homeless assistance systems develop targeted responses to subgroups of homeless people, it becomes increasingly important for our service portfolio to be both varied and validated. Specific subgroups identified though taxonomy development or comprehensive intake assessments will require targeted services of known effectiveness. While we have a glimpse into housing and treatment services that are effective, much more needs to be done to develop a portfolio of effective services. As this effort engages, it will also be important to ensure that we are putting in place processes consistent with translational research principles.

View full report


"report.pdf" (pdf, 443.7Kb)

Note: Documents in PDF format require the Adobe Acrobat Reader®. If you experience problems with PDF documents, please download the latest version of the Reader®