Efficacy and cost-effectiveness of the first generation of HIV prevention interventions for people with severe and persistent mental illness.

BACKGROUND: People with serious mental illness are at elevated risk for human immunodeficiency virus (HIV) infection. A small body of published research has evaluated the efficacy of HIV prevention interventions that aim to help persons with mental illness modify sexual behaviors that place them at risk for HIV infection. Additional research has evaluated the economic efficiency ('cost-effectiveness') of these interventions.

AIMS OF THE STUDY: We provide a detailed and critical review of the efficacy and cost-effectiveness of randomized, controlled trials of HIV prevention interventions for this population. We present a brief overview of the epidemiology of HIV among men and women with serious mental illness and describe HIV risk factors for members of this population. The efficacy literature is critically reviewed, and the results of the available studies are compared using a common effect size metric. The cost-effectiveness of HIV prevention interventions for mentally ill adults is then reviewed.

METHODS: The efficacy of interventions at reducing risk behaviors and increasing preventive behaviors was summarized using effect size estimation techniques. First, we reviewed interventions that have been evaluated in randomized clinical trials and published in the peer-reviewed scientific literature so as to summarize the interventions that have been subjected to the most rigorous evaluation. For each of the five studies that met the inclusion criteria, we briefly described the methodology and intervention content, summarized the evidence for intervention efficacy, and calculated appropriate effect size estimates. A narrative review of two cost-effectiveness studies published to date was included.

RESULTS: The review of intervention efficacy indicated that the risk reduction interventions evaluated to date have had only limited success at helping people with severe mental illness reduce their HIV risk behavior. Most effect sizes indicating successful condom use increases were in the small or small to moderate range. Overall, studies with the largest sample sizes, and presumably the most generalizable results, produced smaller intervention effect sizes than studies with smaller samples. The cost-effectiveness literature revealed similarly mixed results: economic efficiency varied from not cost-effective to highly cost-effective.

DISCUSSION: Limited information is presently available regarding the efficacy and cost-effectiveness of HIV prevention interventions for people with severe and persistent mental illness. Encouraging results were obtained in some, but not all studies. Methodological limitations will need to be addressed in the next generation of HIV risk reduction intervention studies for this population.

IMPLICATIONS FOR HEALTH CARE PROVISION AND USE: Persons with severe mental illness warrant attention from health care providers due to elevated risk for HIV infection. Interventions discussed herein, focusing on information and behavioral skills training, can be employed until strategies with stronger results are developed.

IMPLICATIONS FOR HEALTH POLICIES: Effective and cost-effective HIV risk reduction interventions are available for adults with mental illness and should be more widely implemented. The cost-effectiveness of these interventions could be further enhanced by screening potential participants for high-risk sexual behaviors.

IMPLICATIONS FOR FURTHER RESEARCH: To advance the field, the next generation of intervention research for people with severe mental illness will need to improve upon the designs and intervention strategies of the first generation, include larger samples, and devote increased attention to the life circumstances and particular mental health issues of intervention participants.