A Paradigm shift in Housing and Homeless Services: Applying the ...

Population/High-Risk Homelessness Prevention The Open Health Services and Policy Journal, 2010, Volume 3 45Table 2.Brief Comparison of Prevention FrameworksPrevention frameworkPrimary/Secondary/Tertiary Prevention Universal/Selected/Indicated Prevention Population/High-Risk PreventionGoalPrevent new individual cases and preventworsening of condition among casesPrevent cases among indicated individualsand in selected populations, and preventincidence in the general populationPrevent cases among high-riskpopulations and prevent incidence inthe general populationTemporalityCan be applied to prevent new cases, aswell as to mitigate the harm among currentcasesFocuses efforts on preventing new casesFocuses efforts on preventing newcasesTarget populationIndividuals with risk factors for thecondition and who currently have or havesuffered from the conditionEntire population; high-risk populations;high-risk individualsEntire population; high-riskpopulationsWhatdistinguishes thisframework fromthe othersFocus is on the timing of interventionsFocus is on the target populationFocus is on the context and causes ofthe preventable conditionuniversal/selected/indicated prevention frameworks addressimportant aspects of prevention, only the population/highriskapproach focuses on identifying and targeting the causesof homelessness at multiple levels. It allows us to addressfactors in a population that are ubiquitous, such as thelimited availability of affordable housing, as well as factorsthat are associated with individual cases of homelessness,such as substance use. And rather than focusing on just thetiming of prevention (i.e., primary/secondary/tertiaryprevention) or the target population for prevention programs(i.e., universal/selected/indicated prevention), thisframework concentrates on identifying and eliminating thecauses of homelessness for society as a whole and for themost vulnerable subpopulations. Importantly, thepopulation/high-risk framework does not imply thatprograms and communities must choose between preventionacross the population or prevention among high-risk groups.Instead, applying both prongs of this approachsimultaneously can maximize the overall reach andeffectiveness of prevention programs. The challenge toapplying this prevention approach rests in balancing thestrengths and weaknesses associated with both populationand high-risk strategies.Population-level prevention strategies face two majorchallenges to preventing homelessness: (1) ensuring the“prevention paradox” does not undermine efforts to preventhomelessness among vulnerable populations; and (2)addressing the challenges associated with the political realityof limited resources for prevention efforts. Rose defined theprevention paradox as “a preventive measure which bringsmuch benefit to the population [but] offers little to eachparticipating individual” [53]. This would occur ifprevention activities are diffused throughout the populationin such a way that they do not do enough to help the mostvulnerable individuals. For example, although thefundamental causes of homelessness, such as lack ofaffordable housing, are relevant to all persons, other causesmay also be relevant to vulnerable subgroups. It is likelythat, because of their disabilities, persons with mental illnesswill require both affordable housing and special services inorder to prevent homelessness or to remain stably housed.The second problem with implementing populationstrategies is that resources for preventing homelessness arelimited. If spread too thinly across the entire population,these strategies may not have a significant or detectableimpact on the rate of homelessness. To get results at thepopulation level would require a substantial investment ofcurrently unavailable resources. Given the politicalconstraints which limit resources, high-risk strategies – asopposed to population strategies – could offer a more costeffectiveapproach to prevention by concentrating resourceswhere the need and benefit are likely to be greatest [52].High-risk prevention strategies also pose two majorchallenges: (1) challenges that arise with identifying the“right” people to whom interventions should be targeted; and(2) the challenge of distributing scarce resources to indicatedpeople while holding the overall social environment constant(i.e., the challenge of “queue jumping”) [51]). High-riskprevention strategies are predicated on being able to identifyan appropriate target population based on empiricallyderivedrisk factors of individual cases of homelessness. Ingeneral, the problem of targeting is controlled by the factthat only a small proportion of the general population willever become homeless [5, 6]. Predicting who will fall intothis category is contingent on multiple, identifiable, andunique risk factors, and current screening tests are notsensitive enough to pick up the heterogeneous complexitiesassociated with homelessness [51, 54].Recent studies show that our current methods foridentifying who is most likely to experience homelessnesshave been largely insensitive in predicting who will becomehomeless in the future [55, 56]. 3 The evidence suggests thatresources for preventing homelessness are inevitably spenton some households that would not have become homelesseven without the intervention—an admirable and ethicalexpense, perhaps, but nonetheless not homelessnessprevention. Perhaps more troubling, an even largerproportion of potential homeless households are missed.3 These are problems with all screening tests: when the sensitivity (i.e., theprobability of correctly identifying all those who become homeless from aparticular population) of a test increases, the specificity (i.e., the probabilityof correctly identifying all those who will not become homeless from thatpopulation) will decrease.