Economic evaluation of an HIV prevention intervention for gay and bisexual male adolescents

Evidence Gaps in Economic Evaluations of HIV Interventions Targeting Young People: A Systematic Review

PURPOSE

Young people living with HIV (YPLWH) face the burden of navigating the unique physical, psychological, and social challenges of adolescence while coping with a stigmatized infectious disease that requires lifelong care. Consequently, YPLWH experience worse HIV outcomes compared to children and adults. This systematic review seeks to collate evidence on the health and economic impact of HIV interventions targeting YPLWH and to identify gaps in the available evidence that may inform future economic evaluations of interventions for YPLWH.

METHODS

We searched the MEDLINE, Embase, Scopus, and Global Index Medicus databases for peer-reviewed articles published through April 24, 2022 (PROSPERO ID: CRD42022356244). Our inclusion criteria encompassed economic evaluations of HIV interventions that report health and economic outcomes among individuals ages 10-24 years. Three investigators screened articles at the title, abstract, and full-text levels. The data were extracted in accordance with the Consolidated Health Economic Evaluation Reporting Standards 2022.

RESULTS

Of the 3,735 unique articles retrieved through our search, 32 met our inclusion criteria. Of these 32 articles, 8 (25%) evaluated a behavioral, educational, or financial intervention, 6 (19%) voluntary medical male circumcision, 5 (16%) HIV screening or testing, 4 (13%) pre-exposure prophylaxis, 3 (9%) a hypothetical HIV vaccine, 2 (6%) antiretroviral therapy, 1 (3%) condom distribution, and 3 (9%) a combination of interventions. Twenty-two studies (69%) focused on Africa, 9 (28%) on North America, and 1 (3%) on Europe. Thirty studies (94%) were cost-effectiveness analyses and 2 (6%) were cost-utility analyses. Of the intervention types captured by this review, most were deemed cost-saving or cost-effective. Only two studies-one evaluating a financial intervention and one evaluating HIV testing-concluded that the intervention was not cost-effective.

DISCUSSION

Evidence presented by this review suggests that investments in HIV prevention and treatment for young people can be a cost-effective, and sometimes cost-saving, solution to combating the global HIV epidemic. However, additional evaluations of HIV interventions targeting young people, which adhere to standardized reporting practices, are needed to permit comparability of cost-effectiveness outcomes between interventions and settings.

Model-Based Methods to Translate Adolescent Medicine Trials Network for HIV/AIDS Interventions Findings Into Policy Recommendations: Rationale and Protocol for a Modeling Core (ATN 161)

Background

The United States Centers for Disease Control and Prevention estimates that approximately 60,000 US youth are living with HIV. US youth living with HIV (YLWH) have poorer outcomes compared with adults, including lower rates of diagnosis, engagement, retention, and virologic suppression. With Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) support, new trials of youth-centered interventions to improve retention in care and medication adherence among YLWH are underway.

Objective

This study aimed to use a computer simulation model, the Cost-Effectiveness of Preventing AIDS Complications (CEPAC)-Adolescent Model, to evaluate selected ongoing and forthcoming ATN interventions to improve viral load suppression among YLWH and to define the benchmarks for uptake, effectiveness, durability of effect, and cost that will make these interventions clinically beneficial and cost-effective.

Methods

This protocol, ATN 161, establishes the ATN Modeling Core. The Modeling Core leverages extensive data—already collected by successfully completed National Institutes of Health–supported studies—to develop novel approaches for modeling critical components of HIV disease and care in YLWH. As new data emerge from ongoing ATN trials during the award period about the effectiveness of novel interventions, the CEPAC-Adolescent simulation model will serve as a flexible tool to project their long-term clinical impact and cost-effectiveness. The Modeling Core will derive model input parameters and create a model structure that reflects key aspects of HIV acquisition, progression, and treatment in YLWH. The ATN Modeling Core Steering Committee, with guidance from ATN leadership and scientific experts, will select and prioritize specific model-based analyses as well as provide feedback on derivation of model input parameters and model assumptions. Project-specific teams will help frame research questions for model-based analyses as well as provide feedback regarding project-specific inputs, results, sensitivity analyses, and policy conclusions.

Results

This project was funded as of September 2017.

Conclusions

The ATN Modeling Core will provide critical information to guide the scale-up of ATN interventions and the translation of ATN data into policy recommendations for YLWH in the United States.

Screening for HIV and linkage to care in adolescents: insights from a systematic review of recent interventions in high- versus low- and middle-income settings

Introduction

Compared to adults, adolescents and young adults have a higher incidence of HIV infection, yet lower rates of HIV testing. Few evidence-based interventions effectively diagnose new HIV infections among adolescents while successfully providing linkage to care.

Methods

We conducted a systematic review of recent interventions to increase HIV testing among adolescents and young adults using data retrieved from PubMed and Google Scholar, and using abstracts presented at the International AIDS Society conferences and Conference on Retroviruses and Opportunistic Infections published between January 1, 2015, and April 28, 2018.

Results

We identified 36 interventions (N=14 in high- income countries and N=22 in low- and middle-income countries) that were published in the literature (N=28) or presented at conferences (N=8). Interventions were categorized as behavioral/educational, alternate venue/self-testing, youth-friendly services, technology/mobile health, incentives, or peer-based/community-based interventions. The studies consisted of randomized controlled trials (RCTs), prospective and retrospective observational studies, and quasi-experimental/pre-post evaluations with variable sample sizes. Study designs, populations, and settings varied. All categories showed some degree of acceptability, yet not all interventions were effective in increasing HIV testing. Effectiveness was seen in more than one RCT involving technology/mobile health (2/3 RCTs) and alternative venue/self-testing (3/3 RCTs) interventions, and only in one RCT each for behavioral interventions, community interventions, and incentives. There were no effective RCTs for adolescent-friendly services. Data were limited on the number of new infections identified and on the methods to increase linkage to care after diagnosis.

Conclusion

Future studies should include combinations of proven methods for engaging adolescents in HIV testing, while ensuring effective methods of linkage to care.

Cost effectiveness of the National HIV/AIDS Strategy goal of increasing linkage to care for HIV-infected persons

BACKGROUND

One of the goals of the National HIV/AIDS Strategy (NHAS) is to increase the proportion of HIV-infected individuals linked to care within 3 months of diagnosis (early linkage) from 65% to 85%. Earlier access to care, and eventually, to treatment, increases life expectancy and quality of life for HIV-infected persons. However, longer treatment is also associated with higher costs, especially for antiretroviral drugs. We evaluated the cost effectiveness of achieving the NHAS goal and estimated the maximum cost that HIV programs could spend on linkage to care and remain cost effective.

METHODS

We used the Progression and Transmission of HIV/AIDS model to estimate the effects on life measures and costs associated with increasing early linkage to care from 65% to 85%. We estimated an incremental cost-effectiveness ratio as the additional cost required to reach the target divided by the quality-adjusted life years (QALYs) gained and assumed that programs costing $100,000 or less per QALY gained are cost effective.

RESULTS

Achieving the NHAS linkage-to-care goal increased life expectancy by 0.4 years and delayed the onset of AIDS by 1.2 years on average for every HIV-diagnosed person. Increasing early linkage to care cost an extra $62,200 per QALY gained, considering only benefits to index persons. The maximum that could be cost effectively spent on early linkage-to-care interventions was approximately $5100 per HIV-diagnosed person.

CONCLUSIONS

Considerable investment can be cost effectively made to achieve the NHAS goal on early linkage to care.

The effectiveness of group-based comprehensive risk-reduction and abstinence education interventions to prevent or reduce the risk of adolescent pregnancy, human immunodeficiency virus, and sexually transmitted infections: two systematic reviews for the Guide to Community Preventive Services

CONTEXT

Adolescent pregnancy, HIV, and other sexually transmitted infections (STIs) are major public health problems in the U.S. Implementing group-based interventions that address the sexual behavior of adolescents may reduce the incidence of pregnancy, HIV, and other STIs in this group.

EVIDENCE ACQUISITION

Methods for conducting systematic reviews from the Guide to Community Preventive Services were used to synthesize scientific evidence on the effectiveness of two strategies for group-based behavioral interventions for adolescents: (1) comprehensive risk reduction and (2) abstinence education on preventing pregnancy, HIV, and other STIs. Effectiveness of these interventions was determined by reductions in sexual risk behaviors, pregnancy, HIV, and other STIs and increases in protective sexual behaviors. The literature search identified 6579 citations for comprehensive risk reduction and abstinence education. Of these, 66 studies of comprehensive risk reduction and 23 studies of abstinence education assessed the effects of group-based interventions that address the sexual behavior of adolescents, and were included in the respective reviews.

EVIDENCE SYNTHESIS

Meta-analyses were conducted for each strategy on the seven key outcomes identified by the coordination team-current sexual activity; frequency of sexual activity; number of sex partners; frequency of unprotected sexual activity; use of protection (condoms and/or hormonal contraception); pregnancy; and STIs. The results of these meta-analyses for comprehensive risk reduction showed favorable effects for all of the outcomes reviewed. For abstinence education, the meta-analysis showed a small number of studies, with inconsistent findings across studies that varied by study design and follow-up time, leading to considerable uncertainty around effect estimates.

CONCLUSIONS

Based on these findings, group-based comprehensive risk reduction was found to be an effective strategy to reduce adolescent pregnancy, HIV, and STIs. No conclusions could be drawn on the effectiveness of group-based abstinence education.

Economic evaluation of drug abuse treatment and HIV prevention programs in pregnant women: a systematic review

Drug abuse and transmission of HIV during pregnancy are public health problems that adversely affect pregnant women, their children and surrounding communities. Programs that address this vulnerable population have the ability to be cost-effective due to resulting cost savings for mother, child and society. Economic evaluations of programs that address these issues are an important tool to better understand the costs of services and create sustainable healthcare systems. This study critically examined economic evaluations of drug abuse treatment and HIV prevention programs in pregnant women. A systematic review was conducted using the criteria recommended by the Panel on Cost-Effectiveness in Health and Medicine and the British Medical Journal (BMJ) checklist for economic evaluations. The search identified 6 economic studies assessing drug abuse treatment for pregnant women, and 12 economic studies assessing programs that focus on prevention of mother-to-child transmission (PMTCT) of HIV. Results show that many programs for drug abuse treatment and PMTCT among pregnant women are cost-effective or even cost-saving. This study identified several shortcomings in methodology and lack of standardization of current economic evaluations. Efforts to address methodological challenges will help make future studies more comparable and have more influence on policy makers, clinicians and the public.

Mathematical models for the study of HIV spread and control amongst men who have sex with men

For a quarter of century, mathematical models have been used to study the spread and control of HIV amongst men who have sex with men (MSM). We searched MEDLINE and EMBASE databases up to the end of 2010 and reviewed this literature to summarise the methodologies used, key model developments, and the recommended strategies for HIV control amongst MSM. Of 742 studies identified, 127 studies met the inclusion criteria. Most studies employed deterministic modelling methods (80%). Over time we saw an increase in model complexity regarding antiretroviral therapy (ART), and a corresponding decrease in complexity regarding sexual behaviours. Formal estimation of model parameters was carried out in only a small proportion of the studies (22%) while model validation was considered by an even smaller proportion (17%), somewhat reducing confidence in the findings from the studies. Nonetheless, a number of common conclusions emerged, including (1) identification of the importance of assumptions regarding changes in infectivity and sexual contact rates on the impact of ART on HIV incidence, that subsequently led to empirical studies to gather these data, and (2) recommendation that multiple strategies would be required for effective HIV control amongst MSM. The role of mathematical models in studying epidemics is clear, and the lack of formal inference and validation highlights the need for further developments in this area. Improved methodologies for parameter estimation and systematic sensitivity analysis will help generate predictions that more fully express uncertainty, allowing better informed decision making in public health.

Effectiveness of peer education interventions for HIV prevention in developing countries: a systematic review and meta-analysis

Peer education for HIV prevention has been widely implemented in developing countries, yet the effectiveness of this intervention has not been systematically evaluated. We conducted a systematic review and meta-analysis of peer education interventions in developing countries published between January 1990 and November 2006. Standardized methods of searching and data abstraction were utilized. Merged effect sizes were calculated using random effects models. Thirty studies were identified. In meta-analysis, peer education interventions were significantly associated with increased HIV knowledge (odds ratio [OR]: 2.28; 95%, confidence interval [CI]:1.88, 2.75), reduced equipment sharing among injection drug users (OR: 0.37; 95% CI: 0.20, 0.67), and increased condom use (OR: 1.92; 95% CI: 1.59, 2.33). Peer education programs had a nonsignificant effect on sexually transmitted infections (OR: 1.22; 95% CI:0.88, 1.71). Meta-analysis indicates that peer education programs in developing countries are moderately effective at improving behavioral outcomes but show no significant impact on biological outcomes. Further research is needed to determine factors that maximize the likelihood of program success.

Measuring the value of public health systems: the disconnect between health economists and public health practitioners

We investigated ways of defining and measuring the value of services provided by governmental public health systems. Our data sources included literature syntheses and qualitative interviews of public health professionals. Our examination of the health economic literature revealed growing attempts to measure value of public health services explicitly, but few studies have addressed systems or infrastructure. Interview responses demonstrated no consensus on metrics and no connection to the academic literature. Key challenges for practitioners include developing rigorous, data-driven methods and skilled staff; being politically willing to base allocation decisions on economic evaluation; and developing metrics to capture "intangibles" (e.g., social justice and reassurance value). Academic researchers evaluating the economics of public health investments should increase focus on the working needs of public health professionals.

Behavioral interventions to reduce risk for sexual transmission of HIV among men who have sex with men

BACKGROUND

Men who have sex with men (MSM) remain at great risk for HIV infection. Program planners and policy makers need descriptions of interventions and quantitative estimates of intervention effects to make informed decisions concerning prevention funding and research. The number of intervention strategies for MSM that have been examined with strong research designs has increased substantially in the past few years.

OBJECTIVES

1. To locate and describe outcome studies evaluating the effects of behavioral HIV prevention interventions for MSM.2. To summarize the effectiveness of these interventions in reducing unprotected anal sex.3. To identify study characteristics associated with effectiveness.4. To identify gaps and indicate future research, policy, and practice needs.

SEARCH STRATEGY

We searched electronic databases, current journals, manuscripts submitted by researchers, bibliographies of relevant articles, conference proceedings, and other reviews for published and unpublished reports from 1988 through December 2007. We also asked researchers working in HIV prevention about new and ongoing studies.

SELECTION CRITERIA

Studies were considered in scope if they examined the effects of behavioral interventions aimed at reducing risk for HIV or STD transmission among MSM. We reviewed studies in scope for criteria of outcome relevance (measurement of at least one of a list of behavioral or biologic outcomes, e.g., unprotected sex or incidence of HIV infections) and methodologic rigor (randomized controlled trials or certain strong quasi-experimental designs with comparison groups).

DATA COLLECTION AND ANALYSIS

We used fixed and random effects models to summarize rate ratios (RR) comparing intervention and control groups with respect to count outcomes (number of occasions of or partners for unprotected anal sex), and corresponding prevalence ratios (PR) for dichotomous outcomes (any unprotected anal sex vs. none). We used published formulas to convert effect sizes and their variances for count and dichotomous outcomes where necessary. We accounted for intraclass correlation (ICC) in community-level studies and adjusted for baseline conditions in all studies. We present separate results by intervention format (small group, individual, or community-level) and by type of intervention delivered to the comparison group (minimal or no HIV prevention in the comparison condition versus standard or other HIV prevention in the comparison condition). We examine rate ratios stratified according to characteristics of participants, design, implementation, and intervention content. For small group and individual-level interventions we used a stepwise selection process to identify a multivariable model of predictors of reduction in occasions of or partners for unprotected anal sex. We used funnel plots to examine publication bias, and Q (a chi-squared statistic with degrees of freedom = number of interventions minus 1) to test for heterogeneity.

MAIN RESULTS

We found 44 studies evaluating 58 interventions with 18,585 participants. Formats included 26 small group interventions, 21 individual-level interventions, and 11 community-level interventions. Sixteen of the 58 interventions focused on HIV-positives. The 40 interventions that were measured against minimal to no HIV prevention intervention reduced occasions of or partners for unprotected anal sex by 27% (95% confidence interval [CI] = 15% to 37%). The other 18 interventions reduced unprotected anal sex by 17% beyond changes observed in standard or other interventions (CI = 5% to 27%). Intervention effects were statistically homogeneous, and no independent variable was statistically significantly associated with intervention effects at alpha=.05. However, a multivariable model selected by backward stepwise elimination identified four study characteristics associated with reduction in occasions of or partners for unprotected anal sex among small group and individual-level interventions at alpha=.10. The most favorable reductions in episodes of or partners for unprotected anal sex (33% to 35% decreases) were observed among studies with count outcomes, those with shorter intervention spans (<=1 month), those with better retention in the intervention condition than in the comparison condition, and those with minimal to no HIV prevention intervention delivered to the comparison condition. Because there were only 11 community-level studies we did not search for a multivariable model for community-level interventions. In stratified analyses including only one variable at a time, the greatest reductions (40% to 54% decreases) in number of episodes of or partners for unprotected anal sex among community-level interventions were observed among studies where groups were assigned randomly rather than by convenience, studies with shorter recall periods and longer follow-up, studies with more than 25% non-gay identifying MSM, studies in which at least 90% of participants were white, and studies in which the intervention addressed development of personal skills.

AUTHORS' CONCLUSIONS

Behavioral interventions reduce self-reported unprotected anal sex among MSM. These results indicate that HIV prevention for this population can work and should be supported. Results of previous studies provide a benchmark for expectations in new studies. Meta-analysis can inform future design and implementation in terms of sample size, target populations, settings, goals for process measures, and intervention content. When effects differ by design variables, which are deliberately selected and planned, awareness of these characteristics may be beneficial to future designs. Researchers designing future small group and individual-level studies should keep in mind that to date, effects of the greatest magnitude have been observed in studies that used count outcomes and a shorter intervention span (up to 1 month). Among small group and individual-level studies, effects were also greatest when the comparison condition included minimal to no HIV prevention content. Nevertheless, statistically significant favorable effects were also seen when the comparison condition included standard or other HIV prevention content. Researchers choosing the latter option for new studies should plan for larger sample sizes based on the smaller expected net intervention effect noted above. When effects differ by implementation variables, which become evident as the study is conducted but are not usually selected or planned, caution may be advised so that future studies can reduce bias. Because intervention effects were somewhat stronger (though not statistically significantly so) in studies with a greater attrition in the comparison condition, differential retention may be a threat to validity. Extra effort should be given to retaining participants in comparison conditions. Among community-level interventions, intervention effects were strongest among studies with random assignment of groups or communities. Therefore the inclusion of studies where assignment of groups or communities was by convenience did not exaggerate the summary effect. The greater effectiveness of interventions including more than 25% non-gay identifying MSM suggests that when they can be reached, these men may be more responsive than gay-identified men to risk reduction efforts. Non-gay identified MSM may have had less exposure to previous prevention messages, so their initial exposure may have a greater impact. The greater effectiveness of interventions that include efforts to promote personal skills such as keeping condoms available and behavioral self-management indicates that such content merits strong consideration in development and delivery of new interventions for MSM. And the finding that interventions were most effective for majority white populations underscores the critical need for effective interventions for MSM of African and Latino descent. Further research measuring the incidence of HIV and other STDs is needed. Because most studies were conducted among mostly white men in the US and Europe, more evaluations of interventions are needed for African American and Hispanic MSM as well as MSM in the developing world. More research is also needed to further clarify which behavioral strategies (e.g., reducing unprotected anal sex, having oral sex instead of anal sex, reducing number of partners, avoiding serodiscordant partners, strategic positioning, or reducing anal sex even with condom use) are most effective in reducing transmission among MSM, the messages most effective in promoting these behaviors, and the methods and settings in which these messages can be most effectively delivered.

A Systematic Review of Cost-Utility Analyses in HIV/AIDS: Implications for Public Policy

Objectives . To determine whether gaps exist in published cost-utility analyses as measured by their coverage of topics addressed in current HIV guidelines from the Department of Health and Human Services (DHHS). Design . A systematic review of US-based cost-effectiveness analyses of HIV/AIDS prevention and management strategies, based on original, published research. Methods . Predefined criteria were used to identify all analyses pertaining to prevention and management of HIV/AIDS; information was collected on type of strategy, patient demographics, study perspective, quality of the study, effectiveness measures, costs, and cost-effectiveness ratios. Results . One hundred and six studies were identified; 62 described strategies for averting new HIV infections, and 44 dealt with managing persons who are HIV positive. The quality of studies was generally high, but gaps were found in all studies. Especially common were omissions in reporting data abstraction methodology and discussions of direction and magnitude of potential biases. Among the 22 most highly rated papers (score of 90 or higher), only 1 was cited in the guidelines, and 3 papers reported on interventions that were superseded by newer approaches. Using a $100,000 threshold, the guidelines usually endorsed interventions found to be cost-effective. Exceptions included recommending postexposure prophylaxis (PEP) for populations in which PEP is unlikely to be cost-effective and not recommending primary resistance testing in treatment-naive persons, although the intervention was reported to have a cost-effectiveness ratio of less than $50,000. Conclusions . Despite an abundant literature on the cost-utility of HIV/AIDS-targeted strategies, guidelines cite relatively few of these papers, and gaps exist regarding assessments of some strategies and special populations.

One to one interventions to reduce sexually transmitted infections and under the age of 18 conceptions: a systematic review of the economic evaluations

OBJECTIVE

To systematically review and critically appraise the economic evaluations of one to one interventions to reduce sexually transmitted infections (STIs) and teenage conceptions.

DESIGN

Systematic review.

DATA SOURCES

Search of four electronic bibliographic databases from 1990 to January 2006. Search keywords included teenage, pregnancy, adolescent, unplanned, unwanted, cost benefit, cost utility, economic evaluation, cost effectiveness and all terms for STIs, including specific diseases.

REVIEW METHODS

We included studies that evaluated a broad range of one to one interventions to reduce STIs. Outcomes included major outcomes averted, life years and quality adjusted life years (QALY). All studies were assessed against quality criteria.

RESULTS

Of 3,190 identified papers, 55 were included. The majority of studies found one to one interventions to be either cost saving or cost effective, although one highlighted the need to target the population to receive post-exposure prophylaxis to reduce transmission of HIV. Most studies used a static approach that ignores the potential re-infection of treated patients.

CONCLUSION

One to one interventions have been shown to be cost saving or cost effective but there are some limitations in applying this evidence to the UK policy context. More UK research using dynamic modelling approaches and QALYs would provide improved evidence, enabling more robust policy recommendations to be made about which one to one interventions are cost effective in reducing STIs in the UK setting. The results of this review can be used by policy makers, health economists and researchers considering further research in this area.

A linear programming model for allocating HIV prevention funds with state agencies: a pilot study

Given the initiatives to improve resource allocation decisions for HIV prevention activities, a linear programming model was designed specifically for use by state and local decision-makers. A pilot study using information from the state of Florida was conducted and studied under a series of scenarios depicting the impact of common resource allocation constraints. Improvements over the past allocation strategy in the number of potential infections averted were observed in all scenarios with a maximal improvement of 73%. When allocating limited resources, policymakers must balance efficiency and equity. In this pilot study, the optimal allocation (i.e., most-efficient strategy) would not distribute resources in an equitable manner. Instead, only 12% of at-risk people would receive prevention funds. We find that less efficient strategies, where 58% fewer infections are averted, result in significantly more equitable allocations. This tool serves as a guide for allocating funds for prevention activities.

The cost-effectiveness of health communication programs: what do we know?

While a considerable body of evidence has emerged supporting the effectiveness of communication programs in augmenting health, only a very small subset of studies has examined also whether these programs are cost-effective, that is, whether they achieve greater health gains for available financial resources than alternative interventions. In this article, we examine the available literature on the cost-effectiveness of health behavior change communication programs, focusing on communication interventions involving mass media, and, to a lesser extent, community mobilization and interpersonal communication or counseling. Our objective is to identify the state of past and current research efforts of the cost-effectiveness of behavior change communication programs. This review makes three principal conclusions. First, the analysis of the cost-effectiveness of health communication programs commonly has not been performed. Second, the studies reviewed here have utilized a considerable diversity of methods and have reflected varying levels of quality and adherence to standard cost-effectiveness methodologies. This leads to problems of transparency, comparability, and generalizability. Third, while the available studies generally are indicative of the cost-effectiveness of communication interventions relative to alternatives, the evidence base clearly needs to be expanded by additional rigorous cost-effectiveness analyses.

Quality-adjusted life-years lack quality in pediatric care: a critical review of published cost-utility studies in child health

OBJECTIVES

Cost-utility analysis in which health benefits are quantified in terms of quality-adjusted life-years (QALYs) has now become the standard type of cost-effectiveness analysis. These studies are potentially influential in determining the extent of funding for particular pediatric interventions, and so their methodologic quality is extremely important. The objective of this study was twofold: first, to critically appraise published cost-utility analyses of interventions in child and adolescent health care in terms of the methods used to derive QALYs and, second, to discuss unresolved methodologic issues that are pertinent to the measurement of QALYs in pediatric populations.

METHODS

A comprehensive search using computerized databases (including Medline, Embase, Econlit, and databases specific to economic evaluation), Web searches, and citation tracking was undertaken to identify cost-utility studies of interventions that were aimed at those who were younger than 16 years and published before April 2004. The methods of individual studies were compared with the recognized published guidelines of the US Panel on Cost-Effectiveness in Health and Medicine and the National Institute for Clinical Excellence in England and Wales, which recommend the use of a generic health state classification system (eg, Health Utility Index, EuroQol-5D), a choice-based valuation method (eg, standard gamble or time trade-off) and preferences of the general public in estimating QALYs. Studies therefore were categorized and evaluated according to the methods used to describe the health state, the valuation technique, and source of preferences.

RESULTS

Fifty-four studies were reviewed, 34 (63%) of which were published in the past 5 years. A generic health status classification instrument was used in 22 (35%) cases; the remainder developed study-specific health state descriptions or elicited preferences directly from patients or proxies. In 3 (5%) cases, sources were unclear. Preference weights were elicited using choice-based techniques in 28 (42%) cases, either as tariffs for health status classification instruments (17 cases) or by directly valuing health state descriptions or patient health (11 cases). Preferences of the general public were used in only 23 (37%) cases. Four studies aggregated QALYs for mother/child or parents/child pairs without giving any theoretical justification. Although there was an increasing tendency for studies to use generic health status classification instruments, choice-based methods, and preferences of the general public, the majority of studies still did not adhere to these standard recommendations even in the period between January 2000 and March 2004. Despite increasing standardization in the methods advocated for economic evaluation over the past 10 years, there remains extensive variation in the actual methods used by researchers to calculate QALYs for children and adolescents. It is unclear whether these results suggest poor practice or a set of positive (or reactive) choices made by analysts in a methodologically uncertain area in which specific guidance is lacking regarding how to address the complexities of pediatric outcomes within the QALY framework. Many aspects of QALY measurement in children are not yet fully developed. In particular, there is (1) a lack of appropriate health state classification instruments that take account of the dynamics of child development, (2) a lack of health state classification instruments for use in children and infants who are younger than 5 years, and (3) the need to understand fully the role of proxies for measuring and valuing child health. Additional research efforts are also required to develop methods that account for the health benefits of parents or caregivers of the child and to consider the implications of combining different forms of utility measurement in childhood and adulthood.

CONCLUSIONS

Although variations from standard recommendations may be attributable to poor practice among researchers who are either unaware of these recommendations or choose not to follow them, they could equally be the result of attempts to make research more rigorous and more defensible than it might be if the standard recommendations were followed. There are 4 potential approaches to conducting cost-utility analysis in pediatric populations: (1) the explicit development of a generic instrument designed to be applicable across both child and adult populations (likely to be difficult in practice), (2) insistence on use of a generic instrument developed for adults, (3) the use of generic instruments specifically developed for children without being concerned about comparability with interventions aimed at adults, and (4) abandoning attempts to use single outcome measures that combine mortality with quality weights. In the absence of a clear way forward, it is suggested that an expert panel be convened to debate and further consider these potential solutions and recommendations for best practice and future research. In the interim, comparisons of the relative cost-effectiveness reported as cost per QALY gained across interventions for different diseases and populations should be treated with extreme caution.

Case finding for HIV-positive youth: a special type of hidden population

PURPOSE

To describe the HIV case finding strategies used by the Special Projects of National Significance (SPNS), Adolescent HIV Outreach and Treatment programs, the populations of youth they were able to reach, and the populations of HIV-positive youth they were able to identify.

METHODS

Program specifications from five programs located in four major metropolitan centers were contrasted. Four of the programs also provided outcome data for HIV counseling and testing outcome numbers, demographic and risk profile data for youth who underwent HIV testing, and mode of infection of HIV-positive youth.

RESULTS

The program outcomes were discussed in terms of similarities and differences in outreach methods (e.g., peer workers, time of outreach, etc.), geographic settings (i.e., mobile van, institutional settings, community locations), individual characteristics (e.g., pregnant women) and youth subcultures (i.e., gay/transgendered, incarcerated juveniles, homeless).

CONCLUSIONS

Because HIV-positive adolescents will constitutionally remain a "hidden population," a great deal of time and effort will continue to need to go into the front end of outreach, counseling and testing. Specific guidance and recommendations for locating HIV-positive youth were provided to program designers for each type of outreach strategy.

Interventions to modify sexual risk behaviors for preventing HIV infection in men who have sex with men

BACKGROUND

MSM remain at great risk for HIV infection. Program planners and policy makers need descriptions of interventions and quantitative estimates of intervention effects to make informed decisions concerning prevention efforts.

OBJECTIVES

1. To locate and describe outcome studies evaluating the effects of behavioral and social interventions targeting MSM. 2. To summarize the effectiveness of these interventions among MSM. 3. To stratify results by characteristics of interventions and participants. 4. To identify gaps and indicate future research, policy, and practice needs.

SEARCH STRATEGY

We searched electronic databases (MedLine, PsycInfo, etc.); several current journals (e.g., AIDS, AIDS and Behavior, AIDS Education and Prevention, American Journal of Public Health, Journal of Acquired Immune Deficiency Syndromes, etc.); manuscripts submitted by researchers; bibliographies of relevant articles; and other published reviews, for published and unpublished reports from 1988 through 1997.

SELECTION CRITERIA

Studies were considered in scope if they examined the effects of behavioral interventions to reduce risk for HIV or STD transmission. We reviewed studies in scope for criteria of outcome relevance (measurement of at least one of a list of behavioral or biologic outcomes, e.g., unprotected sex or incidence of HIV infections) and methodologic rigor (randomized controlled trials or certain strong quasi-experimental designs with comparison groups).

DATA COLLECTION AND ANALYSIS

As of June 1998 we had identified 13 eligible studies. Twelve studies (7 trials of small group interventions, 3 community-level interventions, and 2 individual level interventions) reported intervention effects on unprotected sex. Because few studies reported effects on condom use (3 studies), number of sex partners without regard to condom use (4 studies), or HIV or STD incidence (1 study in which no infections occurred) we do not address these outcomes at this time. We present those analyses which can be performed in the current Cochrane RevMan software, followed by more complete analyses that permit inclusion of community-level studies, adjustment for baseline conditions, calculation of effect sizes from a wider variety of statistics (e.g., an F-statistic from a one-way ANOVA), and simultaneous meta-analysis of continuous and dichotomous outcomes (Johnson 2002b). We translate the summary effect to reduction in risk behavior based on the background prevalence of unprotected sex. Finally we provide analyses stratified by intervention content (interpersonal skills addressed or not), intervention format (community vs small group or individual) and mean age of participants (23 to 31 vs. 32 to 36).

MAIN RESULTS

A summary measure of intervention effects on reducing unprotected sex was favorable (odds ratio = 0.73) and statistically significant (CI, 0.60 to 0.88), corresponding to a 23% reduction in the proportion of men engaging in unprotected sex. Effects were homogeneous among studies, but were slightly more favorable among community-level interventions, those that served populations in their 20s rather than their 30s, and those that promoted interpersonal skills.

REVIEWER'S CONCLUSIONS

These studies demonstrate that interventions can promote risk reduction among MSM. Yet given the epidemiology of HIV in Pattern I countries, the small number of rigorous controlled intervention trials for this population is striking. Many more rigorous evaluations of HIV prevention efforts with MSM are needed to ascertain with confidence the effects of specific intervention components, population characteristics, and methodologic features.

AIDS policy modeling for the 21st century: an overview of key issues

Decisions about HIV prevention and treatment programs are based on factors such as program costs and health benefits, social and ethical issues, and political considerations. AIDS policy models--that is, models that evaluate the monetary and non-monetary consequences of decisions about HIV/AIDS interventions--can play a role in helping policy makers make better decisions. This paper provides an overview of the key issues related to developing useful AIDS policy models. We highlight issues of importance for researchers in the field of AIDS policy modeling as well as for policy makers. These include geographic area, setting, target groups, interventions, affordability and effectiveness of interventions, type and time horizon of policy model, and type of economic analysis. This paper is not intended to be an exhaustive review of the AIDS policy modeling literature, although many papers from the literature are discussed as examples; rather, we aim to convey the composition, achievements, and challenges of AIDS policy modeling.

Cost-effectiveness of the Mpowerment Project, a community-level intervention for young gay men

OBJECTIVES

Previous evaluation demonstrated that the Mpowerment Project community-level intervention for young gay men reduces HIV risk behaviors. The current analysis was undertaken to estimate the intervention's health and economic outcomes.

DESIGN/METHODS

We conducted a retrospective cost-effectiveness analysis. We estimated HIV infections averted, the gain in quality-adjusted life years (QALYs), cost per infection averted, and net cost. Using a population-level model, we portrayed two epidemic scenarios: the first with stable HIV prevalence and the other with rising HIV prevalence. Inputs included behavior change resulting from the intervention and program cost data. Cost was calculated from three perspectives: societal; societal excluding volunteer time; and that of a community-based organization (CBO). Outcomes were calculated for 1, 5 (baseline), and 20 years.

RESULTS

The Mpowerment Project averted an estimated 2.0 to 2.3 HIV infections in the first year (according to the epidemic scenario), 5.0 to 6.2 over 5 years, and 9.2 to 13.1 over 20 years. The societal cost per HIV infection averted was estimated at between $14,600 and $18,300 over 5 years. Costs per infection averted were 28% lower when excluding volunteer time and 35% lower from the CBO perspective. Net savings were $700,000 to $900,000 over 5 years from the societal perspective.

CONCLUSIONS

The Mpowerment Project is cost-effective compared with many other HIV prevention strategies. The cost per HIV infection prevented is far less than the lifetime medical costs of HIV disease.

Using cost-effectiveness league tables to compare interventions to prevent sexual transmission of HIV

Cost-effectiveness information is needed to help public health decision makers choose between competing HIV prevention programs. One way to organize this information is in a 'league table' that lists cost-effectiveness ratios for different interventions and which facilitates comparisons across interventions. Herein we propose a common outcome measure for use in HIV prevention league tables and present a preliminary league table of interventions to reduce sexual transmission of HIV in the US. Fifteen studies encompassing 29 intervention for different population groups are included in the table. Approximately half of the interventions are cost-saving (i.e. save society money, in the long run), and three-quarters are cost-effective by conventional standards. We discuss the utility of such a table for informing the HIV prevention resource allocation process and delineate some of the difficulties associated with the league table approach, especially as applied to HIV prevention cost-effectiveness analysis.

Economic evaluation of HIV risk reduction intervention in African-American male adolescents

PURPOSE

To evaluate the cost-effectiveness of a cognitive-behavioral HIV risk reduction intervention for African-American male adolescents that has previously been shown to be effective at reducing sexual risk taking.

METHODS

Standard techniques of cost-utility analysis were employed. A societal perspective and a 3% discount rate were used in the main analysis. Program costs were ascertained retrospectively. A mathematical model of HIV transmission was used to translate observed changes in sexual behavior into an estimate of the number of HIV infections the intervention averted. Intervention effects were assumed to last for 1 year. For each infection averted, the corresponding savings in future HIV-related medical care costs and quality-adjusted life years (QALYs) were estimated. The overall net cost per QALY saved (cost-utility ratio) was then calculated. Sensitivity analyses were performed to assess the robustness of the main results.

RESULTS

The cost-utility ratio was approximately $57,000 U.S. per QALY saved when training costs were included, and $41,000 U.S. per QALY saved when they were excluded. The intervention appeared substantially more cost-effective when the analysis was restricted to the subgroup of participants who reported being sexually active at baseline. Assumptions about the prevalence of HIV infection and the duration of intervention effectiveness also greatly affected the cost-utility ratio.

CONCLUSIONS

The HIV prevention intervention was moderately cost-effective in comparison with other health care programs. Selectively implementing the intervention in high-HIV prevalence communities and with sexually active youth can enhance cost-effectiveness.