Efficient allocation of resources to prevent HIV infection among injection drug users: the Prevention Point Philadelphia (PPP) needle exchange program

Cost-effectiveness analysis of brief and expanded evidence-based risk reduction interventions for HIV-infected people who inject drugs in the United States

AIMS

Two behavioral HIV prevention interventions for people who inject drugs (PWID) infected with HIV include the Holistic Health Recovery Program for HIV+ (HHRP+), a comprehensive evidence-based CDC-supported program, and an abbreviated Holistic Health for HIV (3H+) Program, an adapted HHRP+ version in treatment settings. We compared the projected health benefits and cost-effectiveness of both programs, in addition to opioid substitution therapy (OST), to the status quo in the U.S.

METHODS

A dynamic HIV transmission model calibrated to epidemic data of current US populations was created. Projected outcomes include future HIV incidence, HIV prevalence, and quality-adjusted life years (QALYs) gained under alternative strategies. Total medical costs were estimated to compare the cost-effectiveness of each strategy.

RESULTS

Over 10 years, expanding HHRP+ access to 80% of PWID could avert up to 29,000 HIV infections, or 6% of the projected total, at a cost of $7,777/QALY gained. Alternatively, 3H+ could avert 19,000 infections, but is slightly more cost-effective ($7,707/QALY), and remains so under widely varying effectiveness and cost assumptions. Nearly two-thirds of infections averted with either program are among non-PWIDs, due to reduced sexual transmission from PWID to their partners. Expanding these programs with broader OST coverage could avert up to 74,000 HIV infections over 10 years and reduce HIV prevalence from 16.5% to 14.1%, but is substantially more expensive than HHRP+ or 3H+ alone.

CONCLUSIONS

Both behavioral interventions were effective and cost-effective at reducing HIV incidence among both PWID and the general adult population; however, 3H+, the economical HHRP+ version, was slightly more cost-effective than HHRP+.

Ability to access community-based needle-syringe programs and injecting behaviors among drug users: a cross-sectional study in Hunan Province, China

Background

Needle-syringe exchange programs (NSPs) have been substantially rolled-out in China since 2002. Limited studies reported effectiveness of NSPs in a Chinese setting. This study aimed to assess the association between accessibility to NSPs and drug-use risk behaviors of IDUs by investigating primary (self-reported) data of IDUs recruited from NSP sites, community settings and mandatory detoxification centers (MDCs) in Hunan province, China.

Methods

A cross-sectional survey was conducted in Hunan province in 2010. IDU recruits participated in a face-to-face interview to provide information related to their ability to access NSPs, demographic characteristics, and injecting behaviors in the past 30 days.

Results

Of the total 402 participants, 35%, 14% and 51% participants indicated low, medium and high ability to access NSPs in the past 30 days, respectively. A significantly higher proportion of IDUs (77.3%) from the high-access group reported ≤2 injecting episodes per day compared with medium- (46.3%) and low-access (58.8%) groups. Only 29.0% of high-access IDUs re-used syringes before disposal in the past 30 days, significantly lower than those in the medium- (43.1%) and low-access (41.3%) groups. Reported levels of needle/syringe sharing decreased significantly as the ability to access NSPs increased (16.3%, 12.7% and 2.5% in the low, medium and high access groups, respectively). Ninety percent of IDUs recruited from MDCs had low ability to access NSPs.

Conclusions

Increased NSP accessibility is associated with decreased levels of injecting frequency, repetitive use and sharing of injecting equipment among Chinese IDUs. Mandatory detention of IDUs remains as a major barrier for IDUs to access NSPs in China.

Needle and syringe programs in Yunnan, China yield health and financial return

Background

As a harm reduction strategy in response to HIV epidemics needle and syringes programs (NSPs) were initiated throughout China in 2002. The effectiveness of NSPs in reducing the spread of infection in such an established epidemic is unknown. In this study we use data from Yunnan province, the province most affected by HIV in China, to (1) estimate the population benefits in terms of infections prevented due to the programs; (2) calculate the cost-effectiveness of NSPs.

Methods

We developed a mathematical transmission model, informed by detailed behavioral and program data, which accurately reflected the unique HIV epidemiology among Yunnan injecting drug users (IDUs) in the presence of NSPs. We then used the model to estimate the likely epidemiological and clinical outcomes without NSPs and conducted a health economics analysis to determine the cost-effectiveness of the program.

Results

It is estimated that NSPs in Yunnan have averted approximately 16-20% (5,200-7,500 infections) of the expected HIV cases since 2002 and led to gains of 1,300-1,900 DALYs. The total $1.04 million spending on NSPs from 2002 to 2008 has resulted in an estimated cost-saving over this period of $1.38-$1.97 million due to the prevention of HIV and the associated costs of care and management.

Conclusion

NSPs are not only cost-effective but cost-saving in Yunnan. Significant scale-up of NSPs interventions across China and removal of the societal and political barriers that compromise the effects of NSPs should be a health priority of the Chinese government.

The cost-effectiveness of a modestly effective HIV vaccine in the United States

BACKGROUND

The recent RV144 clinical trial showed that an ALVAC/AIDSVAX prime-boost HIV vaccine regimen may confer partial immunity in recipients and reduce transmission by 31%. Trial data suggest that efficacy may initially exceed 70% but decline over the following 3.5 years. Estimating the potential health benefits associated with a one-time vaccination campaign, as well as the projected benefits of repeat booster vaccination, may inform future HIV vaccine research and licensing decisions.

METHODS

We developed a mathematical model to project the future course of the HIV epidemic in the United States under varying HIV vaccine scenarios. The model accounts for disease progression, infection transmission, antiretroviral therapy, and HIV-related morbidity and mortality. We projected HIV prevalence and incidence over time in multiple risk groups, and we estimated quality-adjusted life years (QALYs) and costs over a 10-year time horizon. We assumed an exponentially declining efficacy curve fit to trial data, and that subsequent vaccine boosters confer similar immunity. Variations in vaccine parameters were examined in sensitivity analysis.

RESULTS

Under existing HIV prevention and treatment efforts, an estimated 590,000 HIV infections occur over 10 years. One-time vaccination achieving 60% coverage of adults could prevent 9.8% of projected new infections over 10 years (and prevent 34% of new infections in the first year) and cost approximately $91,000/QALY gained relative to the status quo, assuming $500 per vaccination series. Targeted vaccination strategies result in net cost savings for vaccines costing less than $750. One-time vaccination of 60% of all adults coupled with three-year boosters only for men who have sex with men and people who inject drugs could prevent 21% of infections for $81,000/QALY gained relative to vaccination of higher risk sub-populations only. A program attaining 90% vaccination coverage prevents 15% of new HIV cases over 10 years (and approximately 50% of infections in the first year).

CONCLUSIONS

A partially effective HIV vaccine with effectiveness similar to that observed in the RV144 trial would provide large health benefits in the United States and could meet conventionally accepted cost-effectiveness thresholds. Strategies that prioritize key populations are most efficient, but broader strategies provide greater total population health benefit.

The cost-effectiveness and population outcomes of expanded HIV screening and antiretroviral treatment in the United States

BACKGROUND

Although recent guidelines call for expanded routine screening for HIV, resources for antiretroviral therapy (ART) are limited, and all eligible persons are not currently receiving treatment.

OBJECTIVE

To evaluate the effects on the U.S. HIV epidemic of expanded ART, HIV screening, or interventions to reduce risk behavior.

DESIGN

Dynamic mathematical model of HIV transmission and disease progression and cost-effectiveness analysis.

DATA SOURCES

Published literature.

TARGET POPULATION

High-risk (injection drug users and men who have sex with men) and low-risk persons aged 15 to 64 years in the United States.

TIME HORIZON

Twenty years and lifetime (costs and quality-adjusted life-years [QALYs]).

PERSPECTIVE

Societal.

INTERVENTION

Expanded HIV screening and counseling, treatment with ART, or both.

OUTCOME MEASURES

New HIV infections, discounted costs and QALYs, and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

One-time HIV screening of low-risk persons coupled with annual screening of high-risk persons could prevent 6.7% of a projected 1.23 million new infections and cost $22,382 per QALY gained, assuming a 20% reduction in sexual activity after screening. Expanding ART utilization to 75% of eligible persons prevents 10.3% of infections and costs $20,300 per QALY gained. A combination strategy prevents 17.3% of infections and costs $21,580 per QALY gained.

RESULTS OF SENSITIVITY ANALYSIS

With no reduction in sexual activity, expanded screening prevents 3.7% of infections. Earlier ART initiation when a CD4 count is greater than 0.350 × 10(9) cells/L prevents 20% to 28% of infections. Additional efforts to halve high-risk behavior could reduce infections by 65%.

LIMITATION

The model of disease progression and treatment was simplified, and acute HIV screening was excluded.

CONCLUSION

Expanding HIV screening and treatment simultaneously offers the greatest health benefit and is cost-effective. However, even substantial expansion of HIV screening and treatment programs is not sufficient to markedly reduce the U.S. HIV epidemic without substantial reductions in risk behavior.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse, National Institutes of Health, and Department of Veterans Affairs.

The cost-effectiveness and population outcomes of expanded HIV screening and antiretroviral treatment in the United States

BACKGROUND

Although recent guidelines call for expanded routine screening for HIV, resources for antiretroviral therapy (ART) are limited, and all eligible persons are not currently receiving treatment.

OBJECTIVE

To evaluate the effects on the U.S. HIV epidemic of expanded ART, HIV screening, or interventions to reduce risk behavior.

DESIGN

Dynamic mathematical model of HIV transmission and disease progression and cost-effectiveness analysis.

DATA SOURCES

Published literature.

TARGET POPULATION

High-risk (injection drug users and men who have sex with men) and low-risk persons aged 15 to 64 years in the United States.

TIME HORIZON

Twenty years and lifetime (costs and quality-adjusted life-years [QALYs]).

PERSPECTIVE

Societal.

INTERVENTION

Expanded HIV screening and counseling, treatment with ART, or both.

OUTCOME MEASURES

New HIV infections, discounted costs and QALYs, and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

One-time HIV screening of low-risk persons coupled with annual screening of high-risk persons could prevent 6.7% of a projected 1.23 million new infections and cost $22,382 per QALY gained, assuming a 20% reduction in sexual activity after screening. Expanding ART utilization to 75% of eligible persons prevents 10.3% of infections and costs $20,300 per QALY gained. A combination strategy prevents 17.3% of infections and costs $21,580 per QALY gained.

RESULTS OF SENSITIVITY ANALYSIS

With no reduction in sexual activity, expanded screening prevents 3.7% of infections. Earlier ART initiation when a CD4 count is greater than 0.350 × 10(9) cells/L prevents 20% to 28% of infections. Additional efforts to halve high-risk behavior could reduce infections by 65%.

LIMITATION

The model of disease progression and treatment was simplified, and acute HIV screening was excluded.

CONCLUSION

Expanding HIV screening and treatment simultaneously offers the greatest health benefit and is cost-effective. However, even substantial expansion of HIV screening and treatment programs is not sufficient to markedly reduce the U.S. HIV epidemic without substantial reductions in risk behavior.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse, National Institutes of Health, and Department of Veterans Affairs.

The cost-effectiveness of consistent and early intervention of harm reduction for injecting drug users in Bangladesh

AIMS

To assess the cost-effectiveness of the CARE-SHAKTI harm reduction intervention for injecting drug users (IDUs) over a 3-year period, the impact on the cost-effectiveness of stopping after 3 years and how the cost-effectiveness might vary with baseline human immunodeficiency virus (HIV) prevalence.

DESIGN

Economic cost data were collected from the study site and combined with impact estimates derived from a dynamic mathematical model.

SETTING

Dhaka, Bangladesh, where the HIV prevalence has remained low despite high-risk sexual and injecting behaviours, and growing HIV epidemics in neighbouring countries.

FINDINGS

The cost per HIV infection prevented over the first 3 years was USD 110.4 (33.1-182.3). The incremental cost-effectiveness of continuing the intervention for a further year, relative to stopping at the end of year 3, is USD 97 if behaviour returns to pre-intervention patterns. When baseline IDU HIV prevalence is increased to 40%, the number of HIV infections averted is halved for the 3-year period and the cost per HIV infection prevented doubles to USD 228.

CONCLUSIONS

The analysis confirms that harm reduction activities are cost-effective. Early intervention is more cost-effective than delaying activities, although this should not preclude later intervention. Starting harm reduction activities when IDU HIV prevalence reaches as high as 40% is still cost-effective. Continuing harm reduction activities once a project has matured is vital to sustaining its impact and cost-effectiveness.

Potential population health outcomes and expenditures of HIV vaccination strategies in the United States

Estimating the potential health benefits and expenditures of a partially effective HIV vaccine is an important consideration in the debate about whether HIV vaccine research should continue. We developed an epidemic model to estimate HIV prevalence, new infections, and the cost-effectiveness of vaccination strategies in the U.S. Vaccines with modest efficacy could prevent 300,000-700,000 HIV infections and save $30 billion in healthcare expenditures over 20 years. Targeted vaccination of high-risk individuals is economically efficient, but difficulty in reaching these groups may mitigate these benefits. Universal vaccination is cost-effective for vaccines with 50% efficacy and price similar to other infectious disease vaccines.

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.