When is an HIV infection prevented and when is it merely delayed?

The Estimated Number and Lifetime Medical Cost of HIV Infections Attributable to Sexually Transmitted Infections Acquired in the United States in 2018: A Compilation of Published Modeling Results

BACKGROUND

The purpose of this study was to estimate the number and lifetime medical cost of HIV infections attributable to incident sexually transmitted infections (STIs) in the United States in 2018.

METHODS

We combined data from published models regarding the number or percentage of HIV infections attributable to STIs with updated estimates of the lifetime medical cost per HIV infection. We used 2 distinct calculation methods. Our first calculation used recent estimates of the percentage of HIV infections in men who have sex with men (MSM) attributable to gonorrhea and chlamydia. Our second calculation, based on older studies, used estimates of the expected number of STI-attributable HIV infections per new STI infection, for gonorrhea, chlamydia, syphilis, and trichomoniasis.

RESULTS

Our first calculation method suggested that 2489 (25th-75th percentiles, 1895-3000) HIV infections in 2018 among MSM could be attributed to gonorrhea and chlamydia, at an estimated lifetime medical cost of $1.05 billion (25th-75th percentiles, $0.79-$1.26 billion). Our second calculation method suggested that 2349 (25th-75th percentiles, 1948-2744) HIV infections in the general population (including MSM) could be attributed to chlamydia, gonorrhea, syphilis, and trichomoniasis acquired in 2018, at an estimated lifetime medical cost of $0.99 billion (25th-75th percentiles, $0.80-$1.16 billion).

CONCLUSIONS

Despite ambiguity regarding the degree to which STIs affect HIV transmission, our combination of data from published STI/HIV transmission models and an HIV lifetime medical cost model can help to quantify the estimated burden of STI-attributable HIV infections in the United States.

Is there life after DEBI? Examining health behavior maintenance in the diffusion of effective behavioral interventions initiative

The evidence-based interventions that are identified, packaged, and disseminated by the Division of HIV/AIDS Prevention at the Centers for Disease Control and Prevention as part of the Diffusion of Effective Behavioral Interventions (DEBI) initiative-commonly referred to the "DEBIs"-currently represent a primary source of HIV prevention interventions for community-based providers. To date, little attention has focused on whether the intended outcomes of the DEBIs, i.e., reductions in HIV-related risk behaviors, are maintained over time. This review summarized evidence for the sustainability of the effects of the DEBIs on HIV sexual risk behavior and intravenous drug use from studies of original and adapted DEBIs. Evidence of intervention decay or a lack of any intervention effect was identified in several original and adapted versions of the DEBIs included in this review. Recommendations include modifications to current criteria for inclusion in the DEBI portfolio, in addition to the development of remediation strategies to address intervention decay. Further, theoretical models that specify the processes that underlie the maintenance of health behaviors over time should be used in developing HIV prevention interventions.

Condom distribution in jail to prevent HIV infection

To determine if a structural intervention of providing one condom a week to inmates in the Los Angeles County Men’s Central Jail MSM unit reduces HIV transmissions and net social cost, we estimated numbers of new HIV infections (1) when condoms are available; and (2) when they are not. Input data came from a 2007 survey of inmates, the literature and intervention program records. Base case estimates showed that condom distribution averted 1/4 of HIV transmissions. We predict .8 new infections monthly among 69 HIV-negative, sexually active inmates without condom distribution, but .6 new infections with condom availability. The discounted future medical costs averted due to fewer HIV transmissions exceed program costs, so condom distribution in jail reduces total costs. Cost savings were sensitive to the proportion of anal sex acts protected by condoms, thus allowing inmates more than one condom per week could potentially increase the program’s effectiveness.

Formulas for estimating the costs averted by sexually transmitted infection (STI) prevention programs in the United States

Background

Sexually transmitted infection (STI) prevention programs can mitigate the health and economic burden of STIs. A tool to estimate the economic benefits of STI programs could prove useful to STI program personnel.

Methods

We developed formulas that can be applied to estimate the direct medical costs and indirect costs (lost productivity) averted by STI programs in the United States. Costs and probabilities for these formulas were based primarily on published studies.

Results

We present a series of formulas that can be used to estimate the economic benefits of STI prevention (in 2006 US dollars), using data routinely collected by STI programs. For example, the averted sequelae costs associated with treating women for chlamydia is given as (C_w)(0.16)(0.925)(0.70)($1,995), where C_w is the number of infected women treated for chlamydia, 0.16 is the absolute reduction in the probability of pelvic inflammatory disease (PID) as a result of treatment, 0.925 is an adjustment factor to prevent double-counting of PID averted in women with both chlamydia and gonorrhea, 0.70 is an adjustment factor to account for the possibility of re-infection, and $1,995 is the average cost per case of PID, based on published sources.

Conclusion

The formulas developed in this study can be a useful tool for STI program personnel to generate evidence-based estimates of the economic impact of their program and can facilitate the assessment of the cost-effectiveness of their activities.

The president's fiscal year 2007 initiative for human immunodeficiency virus counseling and testing expansion in the United States: a scenario analysis of its coverage, impact, and cost-effectiveness

INTRODUCTION

When adjusted for inflation, the federal investment in human immunodeficiency virus (HIV) prevention in the United States has been trending downward for several years. However, for fiscal year 2007, President Bush has proposed to Congress a $93 million increase in HIV prevention efforts focused on HIV counseling and rapid testing in high-risk communities.

OBJECTIVE

Here, we estimate the coverage level of an investment of $93 million for rapid testing and counseling services, estimate the number of HIV infections that might be expected to be prevented by this initiative, and calculate the cost-per-infection-prevented.

METHODS

Standard methods of scenario and cost-effectiveness analysis were employed, and a 1-year time horizon was used. Calculations were done assuming both a societal perspective and a payor perspective.

RESULTS

Assuming full societal perspective costs, about 1.4 million clients could be reached, but if the payor's perspective is used (and clients are assumed to absorb the costs of their time spent and transportation), then coverage could expand to 2.9 million clients. Depending on the perspective used, it is estimated that between 13,014 and 26,984 persons living with HIV could newly learn their serostatus, and that between 1,223 and 2,537 HIV infections could be prevented as a function of the initiative. Under both societal and payor perspectives, the gross cost per infection averted is less than the medical care costs for one case of HIV disease.

CONCLUSIONS

We conclude that the president's proposed $93 million initiative for HIV counseling and rapid testing in the United States would have favorable public health benefits and be cost saving to society (even if it does not address all unmet HIV prevention needs in the United States). However, future research should seek to determine whether rapid counseling and testing are the optimal use of a new $93 million investment in HIV prevention.

Economic Evaluation of an HIV Prevention Intervention for Seropositive Injection Drug Users

OBJECTIVE

To assess the cost-effectiveness of Intervention for HIV-Seropositive injection drug users--Research and Evaluation (INSPIRE), designed to reduce risky sexual and needle-sharing behaviors in research sites in four US cities (2001-2003).

METHODS

We collected data on program and participant costs. We used a mathematical model to estimate the number of sex partners of injection drug users expected to become infected with human immunodeficiency virus (HIV) (with and without intervention), cost of treatment for sex partners who became infected, and the effect of infection on partners' quality-adjusted life expectancy. We determined the minimum effect that INSPIRE must have on condom use among participants for the intervention to be cost-saving (intervention cost less than savings from averted HIV infections) or cost-effective (net cost per quality-adjusted life year saved less than $50,000).

RESULTS

The intervention cost was $870 per participant. It would be cost-saving if it led to 53 percent reduction in the proportion of participants who had any unprotected sex in 1 year and cost-effective with 17 percent reduction. If behavior change lasted 3 months, the cost-effectiveness threshold was 66 percent; if 3 years, the threshold was 6 percent.

CONCLUSIONS

Although cost-saving thresholds may not be achievable by the intervention, we anticipate that cost-effectiveness thresholds will be attained.

Collaborating with an urban community to develop an HIV and AIDS prevention program for black youth and families

This article describes a collaboration between academic researchers and residents of a low-income, inner-city community to develop and deliver an HIV and AIDS prevention program for Black youth. The Chicago HIV Prevention and Adolescent Mental Health Project (CHAMP) Program was developed and implemented to decrease HIV and AIDS risk exposure among youth living in a community that has been dramatically affected by HIV and AIDS. The article outlines (a) phases in the collaborative process to develop the program; (b) strategies used to embed contextually relevant themes and activities that address individual and systemic factors influencing HIV and AIDS risk; (c) a process model, based on the CHAMP experience, that can be replicated to develop programs for other youth problems; (d) descriptions of the CHAMP preadolescent and early adolescent curricula; (e) and how university- and community-based facilitators were trained to collaborate as a team to implement the CHAMP Program. Information is also provided about delivering the program in a distressed urban setting.

Cost-threshold analyses of the National AIDS Demonstration Research HIV prevention interventions

OBJECTIVE

The goal of the multisite National AIDS Demonstration Research (NADR) program was to reduce the sexual and drug injection-related HIV risks of out-of-treatment injection drug users and their sex partners. Previous analyses have established that the NADR interventions were effective at changing participants' risky behaviors. This study was to determine whether the NADR program also was cost-effective.

METHODS

Data from eight NADR study sites were included in the analysis. A mathematical model was used to translate reported sexual and injection-related behavior changes into an estimate of the number of infections prevented by the NADR interventions and then to calculate the corresponding savings in averted HIV/AIDS medical care costs and quality-adjusted years of life, assuming United States values for these parameters. Because cost data were not collected in the original NADR evaluation, the savings in averted medical care costs were compared with the cost of implementing a similar intervention program for injection drug users.

RESULTS

The eight NADR interventions prevented approximately 129 infections among 6629 participants and their partners. Overall, the NADR program would be cost saving (i.e. provide net economic savings) if it cost less than US$2107 per person and would be cost-effective if it cost less than US$10,264 per person. Both of these estimates are considerably larger than the US$273 per person cost of the comparison intervention. There was substantial cross-site variability.

CONCLUSIONS

The results of this analysis strongly suggest that the NADR interventions were cost-saving overall and were, at the very least, cost-effective at all eight sites. In the United States and other developed counties, investments in HIV-prevention interventions such as these have the potential to save substantial economic resources by averting HIV-related medical care expenses among injection drug users.