Cost-effectiveness of antiviral drug therapy to reduce mother-to-child HIV transmission in sub-Saharan Africa

Spending of HIV resources in Asia and Eastern Europe: systematic review reveals the need to shift funding allocations towards priority populations

INTRODUCTION

It is increasingly important to prioritize the most cost-effective HIV interventions. We sought to summarize the evidence on which types of interventions provide the best value for money in regions with concentrated HIV epidemics.

METHODS

We conducted a systematic review of peer-reviewed and grey literature reporting measurements of cost-effectiveness or cost-benefit for HIV/AIDS interventions in Asia and Eastern Europe. We also collated HIV/AIDS spending assessment data from case-study countries in the region.

RESULTS

We identified 91 studies for inclusion, 47 of which were from peer-reviewed journals. Generally, in concentrated settings, prevention of mother-to-child transmission programmes and prevention programmes targeting people who inject drugs and sex workers had lower incremental cost-effectiveness ratios than programmes aimed at the general population. The few studies evaluating programmes targeting men who have sex with men indicate moderate cost-effectiveness. Collation of prevention programme spending data from 12 countries in the region (none of which had generalized epidemics) indicated that resources for the general population/non-targeted was greater than 30% for eight countries and greater than 50% for five countries.

CONCLUSIONS

There is a misalignment between national spending on HIV/AIDS responses and the most affected populations across the region. In concentrated epidemics, scarce funding should be directed more towards most-at-risk populations. Reaching consensus on general principles of cost-effectiveness of programmes by epidemic settings is difficult due to inconsistent evaluation approaches. Adopting a standard costing, impact evaluation, benefits calculation, analysis and reporting framework would enable cross comparisons and improve HIV resource prioritization and allocation.

Optimizing PMTCT service delivery in rural North-Central Nigeria: protocol and design for a cluster randomized study

Nigeria has more HIV-infected women who do not receive needed services for the prevention of mother-to-child transmission of HIV (PMTCT) than any other nation in the world. To meet the UNAIDS/WHO goal of eliminating mother-to-child HIV transmission by 2015, multiple interventions will be required to scale up PMTCT services, especially to lower-level, rural health facilities. To address this, we are conducting a cluster-randomized controlled study to evaluate the impact and cost-effectiveness of a novel, family-focused integrated package of PMTCT services. A systematic re-assignment of patient care responsibilities coupled with the adoption of point-of-care CD4 + cell count testing could facilitate the ability of lower-cadre health providers to manage PMTCT care, including the provision and scale-up of antiretroviral therapy (ART) to pregnant women in rural settings. Additionally, as influential community members, male partners could support their partners' uptake of and adherence to PMTCT care. We describe an innovative approach to scaling up PMTCT service provision that incorporates considerations of where and from whom women can access services (task-shifting), ease of obtaining a CD4 + cell count result (point-of-care testing), the degree of HIV service integration for HIV-infected women and their infants, and the level of family and community involvement (specifically male partner involvement). This systematic approach, if proven feasible and effective, could be scaled up in Nigeria and similar resource-limited settings as a means to accelerate progress toward eliminating mother-to-child transmission of HIV and help women with HIV infection take ART and live long, healthy lives (Trial registration: NCT01805752).

The state of health economic research in South Africa: a systematic review

BACKGROUND

Economic factors are a limiting factor toward the implementation of many health programmes and interventions. Economic evaluation has a great potential to contribute toward cost-effective healthcare delivery in South Africa. Little is known about the characteristics and quality of health economic (including pharmacoeconomic) research in South Africa.

OBJECTIVE AND METHODS

This study assessed the state of health economic (including pharmacoeconomic) research in South Africa. PUBMED, MEDLINE, HealthSTAR, EconLit and PsycINFO databases were searched to identify health economic articles pertaining to South Africa published between 1 January 1977 and 30 April 2010. The searches used the following Medical Subject Headings (MeSH) terms and text words alone and in combination: 'costs', 'health' and 'South Africa'. Our study included only original economic studies/analyses that pertained to South Africa, addressed a health-related topic, and had a statement or word in the title, abstract or keywords that indicated that an economic (including cost) analysis had been conducted. The study only included complete peer-reviewed publications (e.g. abstracts were excluded) that were reported in the English language. Two reviewers independently scored each article in the final sample using the data collection form designed for the study.

RESULTS

In total, 108 studies investigating a wide variety of diseases were included in the study. These articles were published in 39 different journals mostly based outside of South Africa between 1977 and 2010. On average, each article was written by three authors. Most first authors had medical/clinical training and resided in South Africa at the time of publication of their study. Based on a 1-10 scale, with 10 indicating the highest quality, the mean quality score for all studies was 7.59 (SD 1.42) and half of the articles were of good quality (score 8-10) The quality of studies was related to the country in which the journal publishing the article was based (outside South Africa = higher); current residence of the primary author (outside South Africa = higher); method of economic analysis (economic evaluations higher than cost studies); type of data used (secondary higher than primary); primary training of the first author (health economics/pharmacoeconomics = higher); type of medical function (diagnosis = higher); study perspective (societal = higher); primary health intervention (pharmaceuticals = higher); study design (modelling = higher); number of authors (more = higher); and year of publication (more recent = higher) [p ≤ 0.05].

CONCLUSION

Half of the articles were of poor or fair quality. Measures are needed to promote the commissioning of more and better quality health economic and pharmacoeconomic studies in South Africa.

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.

The cost-effectiveness of preventing mother-to-child transmission of HIV in low- and middle-income countries: systematic review

BACKGROUND

Although highly effective prevention interventions exist, the epidemic of paediatric HIV continues to challenge control efforts in resource-limited settings. We reviewed the cost-effectiveness of interventions to prevent mother-to-child transmission (MTCT) of HIV in low- and middle-income countries (LMICs). This article presents syntheses of evidence on the costs, effects and cost-effectiveness of HIV MTCT strategies for LMICs from the published literature and evaluates their implications for policy and future research.

METHODS

Candidate studies were identified through a comprehensive database search including PubMed, Embase, Cochrane Library, and EconLit restricted by language (English or French), date (January 1st, 1994 to January 17th, 2011) and article type (original research). Articles reporting full economic evaluations of interventions to prevent or reduce HIV MTCT were eligible for inclusion. We searched article bibliographies to identify additional studies. Two authors independently assessed eligibility and extracted data from studies retained for review. Study quality was appraised using a modified BMJ checklist for economic evaluations. Data were synthesised in narrative form.

RESULTS

We identified 19 articles published in 9 journals from 1996 to 2010, 16 concerning sub-Saharan Africa. Collectively, the articles suggest that interventions to prevent paediatric infections are cost-effective in a variety of LMIC settings as measured against accepted international benchmarks. In concentrated epidemics where HIV prevalence in the general population is very low, MTCT strategies based on universal testing of pregnant women may not compare well against cost-effectiveness benchmarks, or may satisfy formal criteria for cost-effectiveness but offer a low relative value as compared to competing interventions to improve population health.

CONCLUSIONS AND RECOMMENDATIONS

Interventions to prevent HIV MTCT are compelling on economic grounds in many resource-limited settings and should remain at the forefront of global HIV prevention efforts. Future cost-effectiveness analyses can help to ensure that pMTCT interventions for LMICs reach their full potential by focussing on unanswered questions in four areas: local assessment of rapidly evolving HIV MTCT options; strategies to improve coverage and reach underserved populations; evaluation of a more comprehensive set of MTCT approaches including primary HIV prevention and reproductive counselling; integration of HIV MTCT and other sexual and reproductive health services.

The global strategy to eliminate HIV infection in infants and young children: a seven-country assessment of costs and feasibility

OBJECTIVE

Model the feasibility and affordability of the 2001 UN General Assembly Special Session on AIDS goals to reduce mother-to-child transmission of HIV (MTCT) by 50% by 2010 and achieve 80% coverage of interventions to reduce it among women presenting for antenatal care.

METHODS

The cost and human resource needs of prevention of MTCT (PMTCT) and paediatric treatment were modelled for 2007-2015 and compared with the AIDS budgets and available health workforce in Burkina Faso, Cameroon, Cote d'Ivoire, Malawi, Rwanda, United Republic of Tanzania, and Zambia. Interventions used were promotion of family planning to people living with HIV, HIV testing and counselling, antiretroviral treatment to prevent MTCT and for HIV-infected children, and cotrimoxazole prophylaxis for mothers with advanced HIV infection and HIV-exposed children.

RESULTS

The cumulative cost from 2007 to 2015 of the intervention in the seven countries combined amounted to US$587 688 291, 86% for PMTCT and 14% for paediatric treatment. Three out of the seven countries - Rwanda, Zambia, and Burkina Faso (almost) - were predicted to have sufficient AIDS funding, but only one - Zambia - was predicted to have also sufficient human resources to scale up the interventions by 2010 and sustain them up to 2015. The cost-effectiveness would be less than US$1150 per infection prevented in fully scaled-up programmes.

CONCLUSION

Scaling up PMTCT will require more funds than currently available in many countries, but human resources appear to be a greater bottleneck than funding. We suggest that human resource capacity be assessed when increased funds for PMTCT are requested.

Determinants of HIV counselling and testing participation in a prevention of mother-to-child transmission programme in rural Burkina Faso

OBJECTIVES

To analyse the factors associated with the uptake of HIV counselling, HIV testing and returning for test results in a rural hospital setting in Nouna, Burkina Faso.

METHODS

Cross sectional survey of 435 pregnant women who visited the district hospital for antenatal care, from July to December 2004. Separate multivariate logistic regression analyses including analysis of reported reasons were performed to identify the factors associated with accepting HIV counselling and testing.

RESULTS

HIV testing participation was related to discussing HIV screening with the partner (OR 8.36), and the number of antenatal care (ANC) visits already accomplished (OR 2.23). The quality of pre-test counselling was very poor as 42% did not understand the process. The absence of doctors and mismanagement of time for post-test counselling were the main reasons why women did not receive test results. Analysis of participants by discussion status, counselling and test participation revealed that fewer women dropped out at every stage who discussed HIV testing with their partner.

CONCLUSION

Communication with the partner plays a vital role in the uptake of HIV testing. Encouraging women to engage in a discussion about testing with their partners may be a viable intervention to improve participation. Quality of service needs to be better.

The Value of Contraception to Prevent Perinatal HIV Transmission

OBJECTIVE

The objective of this study was to highlight the value of preventing unintended pregnancies among HIV-infected women as a strategy to prevent perinatal HIV transmission.

GOAL

The goal of this study was to assess the cost-effectiveness of family planning programs to avert HIV-positive births with the current programmatic emphasis: prenatal care services that provide and promote nevirapine for prevention of mother-to-child transmission of HIV.

STUDY DESIGN

Cost-effectiveness analyses were conducted from the health system perspective during 1 year with a hypothetical sub-Saharan African population. Expected program costs were combined with number of HIV-positive births averted for each strategy.

RESULTS

At the same level of expenditure, the contraceptive strategy averts 28.6% more HIV-positive births than nevirapine for prevention of mother-to-child transmission of HIV.

CONCLUSIONS

Increasing contraceptive use among nonusers of contraception who do not want to get pregnant is cost-effective and is an equally important strategy to prevent perinatal transmission as prenatal care programs that provide and promote nevirapine to HIV-infected mothers.

Clinical impact and cost-effectiveness of co-trimoxazole prophylaxis in patients with HIV/AIDS in Côte d'Ivoire: a trial-based analysis

BACKGROUND

In 2000, WHO/UNAIDS recommended co-trimoxazole prophylaxis for persons at early stages of HIV infection (WHO stage > or = 2) in sub-Saharan Africa.

OBJECTIVE

To assess the cost-effectiveness of alternative strategies for initiation of co-trimoxazole in Côte d'Ivoire.

DESIGN

Cost-effectiveness analysis with an HIV simulation model using clinical and cost data from a randomized trial of co-trimoxazole in HIV-infected adults.

METHODS

The study included HIV-infected patients in Côte d'Ivoire, with median age 33 years. Thirty-four percent were classified as WHO stage 2, 59% as stage 3, and 7% as stage 4. The mean CD4 cell count was 331 x 10(6) cells/l. The interventions were no prophylaxis, clinical criteria-based co-trimoxazole initiation (early: WHO stage > or = 2; late: WHO stage > or = 3), CD4-based co-trimoxazole initiation (< 500, < 200, < 50 x 10(6) CD4 cells/l). The outcome measures were life expectancy, lifetime costs, and incremental cost-effectiveness.

RESULTS

The most effective strategy, initiation of co-trimoxazole prophylaxis at WHO stage > or = 2, increased undiscounted life expectancy by 5.2 months, discounted life expectancy by 4.4 months, and lifetime costs by US dollars 60, compared with no prophylaxis. Delaying prophylaxis initiation until WHO stage >or = 3 was less costly and less effective. All CD4-based strategies were dominated. The incremental cost-effectiveness of early versus late co-trimoxazole prophylaxis initiation was US dollars 200/year of life gained. Results were stable despite wide variations in plausible assumptions about bacterial resistance and the prophylaxis efficacy on co-trimoxazole-resistant strains.

CONCLUSIONS

For HIV-infected adults in Côte d'Ivoire, co-trimoxazole prophylaxis is reasonably cost-effective and most effective if initiated when WHO stage > or = 2. Early co-trimoxazole prophylaxis will prevent complications prior to antiretroviral therapy initiation and should be considered an essential component of care for early HIV in sub-Saharan Africa.

Cost-effectiveness of antenatal HIV-testing: reviewing its pharmaceutical and methodological aspects

This paper reviews the pharmacoeconomic aspects of antenatal testing for HIV. HIV is a retrovirus which is transmitted among humans through sexual contact, infected blood or blood products (needle sharing or percutaneous accidents) and from mother to child (vertical transmission). Vertical transmission from the HIV-infected mother can occur in utero during and after delivery, through breastfeeding. Effective interventions available to reduce the risk of vertical transmission include: pharmacotherapy prior, during and after delivery; voluntary caesarean section; and replacing breastfeeding by bottle-feeding [1,2]. The existence of these effective interventions underlies the need to detect yet undiagnosed HIV-infection in pregnancy through antenatal testing. Contemporary pharmacotherapy consists of a combination of three or more antiretroviral drugs, also referred to as highly-active antiretroviral therapy (HAART). For newly detected HIV-infected mothers, the Centers for Disease Control suggests the use of a zidovudine-comprising combination with one other nucleoside analogue reverse transcriptase inhibitor and a protease inhibitor (PI) [3]. As HIV in pregnancy may be asymptomatic, structured antenatal HIV-testing therefore seems to offer an attractive prevention strategy. Two broad types of approaches exist: selective or targeted testing versus universal testing. The availability of effective - but expensive - combination therapies since 1996 has greatly enhanced the importance of pharmacoeconomic assessments in the field of HIV-infection. Treatment of the mother will incur additional costs but will also make any programme more effective. Furthermore, avoiding children becoming infected with HIV will also incur monetary benefits, as children are also being treated with HAART. In summary, the background of antenatal HIV-testing has undergone major changes compared with the early 1990s. This review of the pharmacoeconomics of antenatal HIV-testing followed a systematic approach as it was performed according to prespecified criteria, allowing valid comparisons in methodologies and findings of those studies that have yet been conducted in this area.

Cost-effectiveness of nevirapine to prevent mother-to-child HIV transmission in eight African countries

BACKGROUND

A comprehensive approach to preventing HIV infection in infants has been recommended, including: (a) preventing HIV in young women, (b) reducing unintended pregnancies among HIV-infected women, (c) preventing vertical transmission (PMTCT), and (d) providing care, treatment, and support to HIV-infected women and their families. Most attention has been given to preventing vertical transmission based on analysis showing nevirapine to be inexpensive and cost-effective.

METHODS

The following were determined using data from eight African countries: national program costs and impact on infant infections; reductions in adult HIV prevalence and unintended pregnancies among HIV-infected women that would have equivalent impact on infant HIV infections averted as the nevirapine intervention; and the cost threshold for drugs with greater efficacy than nevirapine yielding an equivalent cost per DALY saved.

RESULTS

Average national annual program cost was 4.8 million dollars. There was, per country, an average of 1898 averted infant HIV infections (2517 US dollars per HIV infection and 84 US dollars per DALY averted). Lowering HIV prevalence among women by 1.25% or reducing unintended pregnancy among HIV-infected women by 16% yielded an equivalent reduction in infant cases. An antiretroviral drug with 70% efficacy could cost 152 US dollars and have the same cost per DALY averted as nevirapine at 47% efficacy.

CONCLUSIONS

Cost-effectiveness of nevirapine prophylaxis is influenced by health system costs, low client uptake, and poor effectiveness of nevirapine. Small reductions in maternal HIV prevalence or unintended pregnancy by HIV-infected women have equivalent impacts on infant HIV incidence and should be part of an overall strategy to lessen numbers of infant infections.

A review of studies assessing the costs and consequences of interventions to reduce mother-to-child HIV transmission in sub-Saharan Africa

OBJECTIVE

To review the methods and findings of studies that assess the costs and consequences of interventions to reduce mother-to-child HIV transmission in sub-Saharan Africa.

DESIGN

Systematic literature review.

METHODS

A literature search was conducted to identify studies that assessed the costs and consequences of interventions aimed at reducing mother-to-child HIV transmission in African populations. The methodological quality of included studies was appraised using the British Medical Journal Economic Evaluation Working Party checklist and data were extracted for comparison using a data extraction template.

RESULTS

Nine studies, all of which used modelling techniques to predict the cost-effectiveness of anti-retroviral interventions, were identified for inclusion in the review. The quality of reporting was found to be lacking in several key areas. In particular a lack of detail was given regarding quantities of resources required for interventions, and the methods for valuing health outcomes and unit costs. In general, the more recent evaluations report more favourable cost-effectiveness ratios than earlier studies due to lower drug costs and in some cases the use of shorter drug regimens.

CONCLUSIONS

Comparisons between studies were hampered by variations in the values attached to model parameters and by differences in the structure and design of models. The most encouraging findings have been reported for the CDC short zidovudine regimen and the HIVNET012 single dose nevirapine regimen. The generalizability of these findings is limited by the use of incremental costing, combined with uncertainty surrounding the level of infrastructure required to implement the interventions. In low-income sub-Saharan countries, the costs of strengthening the infrastructure to levels capable of providing such interventions, needs to be assessed before an optimal policy for the prevention of mother-to-child HIV transmission in sub-Saharan Africa can be established.

Potential benefit and limitations of a broad access to potent antiretroviral therapy in developing countries

In industrialised countries, highly active antiretroviral therapy (HAART) has drastically reduced HIV mortality. Only few developing countries have introduced HAART on a large scale, leaving millions of HIV-infected individuals without life-saving therapy. Although HAART appears to be economically viable for middle income countries, it remains unaffordable for many of the poorest and worst affected nations. In response, significant discounts for antiretrovirals and debt relief have been granted. Apart from economic problems, other important issues need to be addressed before antiretroviral therapy can be optimally utilised, including the logistics of drug supply, HIV education for hospital staff and patients, and laboratory facilities that allow clinicians to assess the efficacy of HAART.

Cost-effectiveness of HIV/AIDS interventions in Africa: a systematic review of the evidence

BACKGROUND

Evidence for cost-effectiveness of interventions for HIV/AIDS in Africa is fragmentary. Cost-effectiveness is, however, highly relevant. African governments face difficult choices in striking the right balance between prevention, treatment, and care, all of which are necessary to deal comprehensively with the epidemic. Reductions in drug prices have raised the priority of treatment, though treatment access is restricted. We assessed the existing cost-effectiveness data and its implications for value-for-money strategies to combat HIV/AIDS in Africa.

METHODS

We undertook a systematic review using databases and consultations with experts. We identified over 60 reports that measured both the cost and effectiveness of HIV/AIDS interventions in Africa. 24 studies met our inclusion criteria and were used to calculate standardised estimates of the cost (US$ for year 2000) per HIV infection prevented and per disability-adjusted life-year (DALY) gained for 31 interventions.

FINDINGS

Cost-effectiveness varied greatly between interventions. A case of HIV/AIDS can be prevented for $11, and a DALY gained for $1, by selective blood safety measures, and by targeted condom distribution with treatment of sexually transmitted diseases. Single-dose nevirapine and short-course zidovudine for prevention of mother-to-child transmission, voluntary counselling and testing, and tuberculosis treatment, cost under $75 per DALY gained. Other interventions, such as formula feeding for infants, home care programmes, and antiretroviral therapy for adults, cost several thousand dollars per infection prevented, or several hundreds of dollars per DALY gained.

INTERPRETATION

A strong economic case exists for prioritisation of preventive interventions and tuberculosis treatment. Where potentially exclusive alternatives exist, cost-effectiveness analysis points to an intervention that offers the best value for money. Cost-effectiveness analysis is an essential component of informed debate about priority setting for HIV/AIDS.

Paying to waste lives: the affordability of reducing mother-to-child transmission of HIV in South Africa

It is estimated that each HIV-positive child in South Africa costs the government more in terms of health and welfare expenses than it does to reduce mother-to-child transmission (MTCT) of HIV through the use of antiretroviral regimens (where the mother continues to breast-feed). Programmes to reduce MTCT of HIV/AIDS are, thus, clearly affordable. Using Nevirapine (according to the HIVNET 012 Protocol) saves more lives and [corrected] is more cost-effective than using Zidovudine (CDC 2 weeks regime).

Introduction to health economics for physicians

Since the 1960s, expenditure on health care in developed countries has risen faster than the general rate of inflation, thus making economic assessment of interventions an integral part of decision making in health services. This paper is the first in a series whose goal is to provide some basic principles of health economics that will allow practising physicians to understand better the economic relations between their practice of medicine, the health-care sector, and the national economy. Some of the most important principles described in this paper include opportunity costs, identifying the appropriate perspective, correctly categorising costs, and discounting costs and non-monetary benefits (eg, lives saved) over time. Economic analyses of medical interventions must also take into consideration the difference between efficacy and effectiveness. Efficacy is the maximum possible benefit, often achieved with carefully controlled trials, and effectiveness is the actual decrease in disease achieved when the intervention is applied over a large, non-homogeneous population. This introduction ends with three methods of assessing the costs and benefits of an intervention-namely, cost-benefit, cost-effectiveness, and cost-utility analyses.

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.

Economic evaluation of communicable disease interventions in developing countries: a critical review of the published literature

Limited health care budgets have emphasized the need for providers to use resources efficiently. Accordingly, there has been a rapid increase in the number of economic evaluations of communicable disease health programmes in developing countries, as there is a need to implement evidence-based policy decisions. However, given the prohibitive cost of many economic evaluations in low-income countries, interest has also been generated in pooling data and results of previously published studies. Yet, our review demonstrated that very few published economic evaluations have been performed during 1984-1997 (n=107). Certain diseases and geographical areas have also been neglected. Of those studies published, appropriate analytic techniques have been inconsistently applied. In particular, there are four immediate concerns: the narrow perspective taken-dominance of the health care provider viewpoint and reliance on intermediate outcomes measures; bias-some costs were excluded from estimates; the lack of transparency-sources of data not identified; and the absence of a critical examination of findings-many papers failed to perform a sensitivity analysis. The usefulness of previously published economic evaluations to help make resource allocation choices on an individual basis and, therefore, for the purpose of international comparisons, pooling or meta-analysis, has to be questioned in light of the results from this study.

Strategies for prevention of mother-to-child transmission of HIV

Over 90 per cent of paediatric HIV infections are maternally acquired, most of these in sub-Saharan Africa. Mortality trends underscore the humanitarian and ethical obligation for urgent global action to protect children from HIV. With the adoption of anti-retroviral therapy in pregnancy, mother-to-child transmission rates have declined to 4-6 per cent in the USA and other industrialised countries. In low-resource settings, where most of the children are continuously being exposed to HIV, the cost of anti-retroviral therapy is prohibitive. Very few developing countries apart from Botswana, Thailand and Brazil have national policies for integration of preventive anti-retroviral therapy in antenatal clinics. This paper reviews anti-retroviral and non-anti-retroviral interventions for prevention of mother-to-child transmission of HIV. To support the health of mothers as well, it supports the implementation of a comprehensive package of care in pregnancy and post-partum, such as access to antenatal and delivery services; anti-retroviral preventive therapy; malaria treatment; family planning; multivitamin, iron and folate supplementation; counselling on feeding options; post-natal care for the child and post-partum care for the mother, and calls for a strategy for advocacy, programme communication and community mobilisation.

Effect of human immunodeficiency virus infection on episodes of diarrhea among children in South Africa

BACKGROUND

Infection with HIV is increasing among children in South Africa. Diarrhea is a common cause of morbidity and mortality in Africa, and some studies have shown that HIV-infected children have episodes of severe diarrhea with higher mortality than HIV-uninfected children.

OBJECTIVES

To compare the severity, pathogens and outcome of diarrhea in HIV-infected and uninfected children.

METHODS

We studied 181 children ages 3 months to 4 years admitted for gastroenteritis to the Chris Hani Baragwanath Hospital in Soweto, South Africa. Demographic details of the children were recorded, as were the details of the episode of diarrhea. Stools specimens were collected and sent for microbiologic evaluation. The clinical course of the child's admission was recorded. Children were diagnosed as being infected with HIV if they tested positive by HIV enzyme-linked immunosorbent assay (ELISA) and were >15 months of age, or if they were ELISA-positive, were < 15 months of age and had clinical signs of HIV infection.

RESULTS

Of the 176 children with an HIV ELISA result, 31 (17.6%) were classified as HIV-infected. More HIV-infected children were malnourished (80.6% vs. 39.5%, P < 0.001) and more likely to have had prolonged diarrhea (16.1% vs. 5.9%, P = 0.07) compared with HIV-uninfected children. HIV-infected children had a higher rate of a codiagnosis of pneumonia (43.3% vs. 9.2%, P < 0.0001) and were more likely to require a hospital stay of >4 days (prevalence odds ratio, 5.11; 95% confidence interval, CI 1.49 to 17.52). There were no significant differences in stool pathogens or in the level of dehydration on admission between the HIV-infected and uninfected children.

CONCLUSION

HIV-infected children have the same spectrum of enteric pathogens as uninfected children but require more attention because of malnutrition and comorbidity.

Trends in Prevention of Mother-to-Child Transmission of HIV-1

Mother-to-child transmission (MTCT) of HIV is the predominant mode of HIV transmission in children worldwide. It is estimated that around 1.3 million children are living with HIV and that approximately 1,600 children are infected with HIV each day. Numerous clinical trials using antiretroviral drugs to reduce MTCT of HIV-1 have shown that perinatal transmission can be reduced effectively. Based on the PACTG 076 study administering a long antenatal zidovudine regimen, a signific ant reduction in vertical HIV-1 transmission has been achieved in the developed world. Trials conducted in developing countries have shown that perinatal transmission can be reduced effectively even using shorter and less costly antiretroviral regimens. Prevention of MTCT interventions have been implemented on a large scale in a number of developing countries.

Economic issues in the prevention of vertical transmission of HIV

In the absence of interventions, 20% of infants born to women infected with HIV acquire infection from their mother at or before delivery. A further 15% are infected through breast feeding. Prenatal testing for HIV allows infected women to be reliably identified so that they can receive antiretroviral therapy and, in countries with safe water supplies, be advised not to breast feed. These and other interventions can reduce the risk of transmission to 5% or less. Economic evaluations of prenatal testing for HIV are reviewed and compared in this article, and future research priorities outlined. These studies set the costs of testing and intervention against the averted lifetime costs of paediatric infection, and generate estimates of the HIV prevalence threshold above which there would be a net cost saving, or calculate the cost per life-year saved given a particular prevalence. In the developed world, prenatal testing has been adopted in many countries, and recent economic analyses broadly support this. Future research is likely to focus on the incremental benefits of different antiretroviral regimens in lowering transmission rates still further, with or without elective caesarean section, and the possibility that some may lead to adverse effects in uninfected infants exposed to them in utero. Some earlier assessments in resource-poor settings concluded that prenatal testing was unaffordable or of doubtful cost effectiveness. This negative conclusion appears to be the result of very low estimates of the lifetime costs of paediatric HIV infection, together with developed world conceptions of pre-test counselling. The demonstration that nevirapine reduces transmission risk at a low cost has transformed the outlook, and there is hope that antiretrovirals can act prophylactically to prevent infection of the breast-fed child. However, to achieve a sustained reduction in vertical transmission there may be a need to evaluate the need for a strengthened infrastructure to deliver prenatal HIV testing and treatment, as well as programmes to reduce HIV incidence in adults.

Extent to which low-level use of antiretroviral treatment could curb the AIDS epidemic in sub-Saharan Africa

BACKGROUND

Despite growing international pressure to provide HIV-1 treatment to less-developed countries, potential demographic and epidemiological impacts have yet to be characterised. We modelled the future impact of antiretroviral use in South Africa from 2000 to 2005.

METHODS

We produced a population projection model that assumed zero antiretroviral use to estimate the future demographic impacts of the HIV-1 epidemic. We also constructed four antiretroviral-adjusted scenarios to estimate the potential effect of antiretroviral use. We modelled total drug cost, cost per life-year gained, and the proportion of per-person health-care expenditure required to finance antiretroviral treatment in each scenario.

FINDINGS

With no antiretroviral use between 2000 and 2005, there will be about 276,000 cumulative HIV-1-positive births, 2,302,000 cumulative new AIDS cases, and the life expectancy at birth will be 46.6 years by 2005. By contrast, 110,000 HIV-1-positive births could be prevented by short-course antiretroviral prophylaxis, as well as a decline of up to 1 year of life expectancy. The direct drug costs of universal coverage for this intervention would be US$54 million--less than 0.001% of the per-person health-care expenditure. In comparison, triple-combination treatment for 25% of the HIV-1-positive population could prevent a 3.1-year decline in life expectancy and more than 430,000 incident AIDS cases. The drug costs of this intervention would, however, be more than $19 billion at present prices, and would require 12.5% of the country's per-person health-care expenditure.

INTERPRETATION

Although there are barriers to widespread HIV-1 treatment, limited use of antiretrovirals could have an immediate and substantial impact on South Africa's AIDS epidemic.

Incremental cost-effectiveness of two zidovudine regimens to prevent perinatal HIV transmission in the United States

BACKGROUND

Recently concluded clinical trials in Thailand have demonstrated that a short course of zidovudine therapy administered to human immunodeficiency virus-infected women during late pregnancy and labor can substantially reduce the likelihood of perinatal transmission of HIV. This regimen is both less expensive and less effective than the full course of therapy recommended for use in the United States by the U.S. Public Health Service (PHS). The objective of the current study is to estimate the incremental cost-effectiveness of the full-course zidovudine regimen in comparison to the short-course regimen that was tested in Thailand and to determine conditions under which the PHS-recommended regimen produces a net savings in societal resource utilization, relative to the shorter regimen.

METHODS

We used standard methods of incremental cost-effectiveness analysis and derived cost and effectiveness estimates from published studies. The main outcome measure is the incremental cost-effectiveness ratio, which is the additional cost per additional case of perinatal HIV infection averted by the full course of therapy.

RESULTS

Full-course zidovudine therapy costs an additional $21,337 per additional case of HIV infection averted, relative to the shorter regimen; this is much less than the cost of treating a case of pediatric HIV infection.

CONCLUSIONS

Economic and clinical findings both favor full-course zidovudine therapy over short-course therapy to prevent perinatal transmission of HIV in the United States.

Cost effectiveness of single-dose nevirapine regimen for mothers and babies to decrease vertical HIV-1 transmission in sub-Saharan Africa

BACKGROUND

Identification of economical interventions to decrease HIV-1 transmission to children is an urgent public-health priority in sub-Saharan Africa. We assessed the cost effectiveness of the HIVNET 012 nevirapine regimen.

METHODS

We assessed cost effectiveness in a hypothetical cohort of 20,000 pregnant women in sub-Saharan Africa. Our main outcome measures were programme cost, paediatric HIV-1 cases averted, cost per case averted, and cost per disability-adjusted life-year (DALY). We compared HIVNET 012 with other short-course antiretroviral regimens. We also compared two implementation strategies: counselling and HIV-1 testing before treatment (targeted treatment), or nevirapine for all pregnant women (universal treatment, no counselling and testing). We did univariate and multivariate sensitivity analyses.

FINDINGS

For universal treatment with 30% HIV-1 seroprevalence, the HIVNET 012 regimen would avert 603 cases of HIV-1 in babies, cost US$83,333, and generate 15,862 DALYs. The associated cost-effectiveness ratios were $138 per case averted or $5.25 per DALY. At 15% seroprevalence, the universal treatment option would cost $83,333 and avert 302 cases at $276 per case averted or $10.51 per DALY. For targeted treatment at 30% seroprevalence, HIVNET 012 would cost $141,922 and avert 476 cases at $298 per case averted or $11.29 per DALY. With seroprevalence higher than 3.0% for universal and 4.5% for targeted treatment, the HIVNET 012 regimen was likely to be as cost effective as other public-health interventions. The cost effectiveness of HIVNET 012 was robust under a wide range of parameters in the sensitivity analysis.

INTERPRETATION

The HIVNET 012 regimen can be highly cost-effective in high seroprevalence settings. In lower seroprevalence areas, when multidose regimens are not cost effective, nevirapine therapy could have a major public-health impact at a reasonable cost.

Thalidomide stimulates T cell responses and interleukin 12 production in HIV-infected patients

We performed a placebo-controlled study to evaluate the effects of immunomodulatory treatment with thalidomide on HIV levels, TNF-alpha levels, and immune status of 31 HIV-infected individuals, after temporary suppression of viral replication with antiretroviral drugs. Treatment with a combination of zidovudine and lamivudine (ZDV/LMV) for 14 days resulted in a median decline in plasma viremia of 1.94 log10 RNA equivalents/ml. After discontinuation of ZDV/LMV, thalidomide therapy (200 mg/day for 4 weeks) did not retard the prompt return of HIV titers to the pretreatment levels, and had no effect on plasma levels of TNF-alpha. In contrast, thalidomide treatment resulted in significant immune stimulation. We observed increased levels of plasma soluble IL-2 receptor, soluble CD8 antigen, and IL-12 (p < 0.01 for all parameters), as well as increased cutaneous delayed-type hypersensitivity reactions to recall antigens (p < 0.01) in thalidomide-treated patients. These changes were associated with a median increase in HIV titer of 0.2 log10 RNA equivalents/ml in the thalidomide-treated group (p < 0.05), which resolved after stopping the drug. Further studies were performed in vitro to elucidate the mechanism of thalidomide-induced immune stimulation. When purified T cells from HIV-infected individuals were stimulated by immobilized anti-CD3 in the presence of thalidomide, a costimulatory effect of the drug was observed, resulting in increased production of IL-2 and IFN-gamma, and increased T cell-proliferative responses. Further experiments showed that thalidomide increased IL-12 production by antigen-presenting cells in a T cell-dependent manner. Our findings suggest a potential application for thalidomide as a novel immune adjuvant in HIV disease.

Costs and benefits to the mother of antenatal HIV testing: estimates from simulation modelling

OBJECTIVE

To assess the health service costs and benefits for the woman of an earlier HIV diagnosis as a result of antenatal HIV testing.

DESIGN

A model of maternal disease progression was developed based on the rate of decline in CD4 cell counts and applied to two matched simulated cohorts of women with identical initial CD4 cell levels and decline rates but whose HIV diagnosis occurred at different times as a result of antenatal HIV testing. UK data on CD4 cell count at HIV diagnosis and annual health service costs of care excluding antiretroviral therapy (ART) incurred at defined states of CD4 cell count were taken from published UK data. Costs of triple ART were added and effectiveness modelled by retarding the rate of CD4 cell count decline. Discounting costs at 6% and life-years at 2% per year, the additional costs per life-year gained by screening were calculated. Uncertainty was explored using sensitivity analysis.

RESULTS

Costs per life-year gained by antenatal diagnosis of women were pound sterling 51258 ($76887) assuming untested women were diagnosed a median of 20.4 months later than tested women, ART was initiated at a CD4 cell count of 350x10(6) cells/l and ART efficacy retarded decline in CD4 cell counts by 40% for life. Sensitivity analyses showed results were most sensitive to the assumed efficacy of lifetime ART and time assumed to HIV diagnosis for women not tested in pregnancy.

CONCLUSION

This model provides a way of estimating the additional costs and benefits of future care for the woman resulting from an earlier HIV diagnosis through antenatal testing. These should be included with the paediatric costs averted and life-years gained from interventions to reduce mother-to-child transmission in order to evaluate the cost-effectiveness of antenatal screening in different populations and settings.

Prevention of vertical transmission of HIV: analysis of cost effectiveness of options available in South Africa

OBJECTIVE

To assess the cost effectiveness of vertical transmission prevention strategies by using a mathematical simulation model.

DESIGN

A Markov chain model was used to simulate the cost effectiveness of four formula feeding strategies, three antiretroviral interventions, and combined formula feeding and antiretroviral interventions on a cohort of 20 000 pregnancies. All children born to HIV positive mothers were followed up until age of likely death given current life expectancy and a cost per life year gained calculated for each strategy.

SETTING

Model of working class, urban South African population.

RESULTS

Low cost antiretroviral regimens were almost as effective as high cost ones and more cost effective when formula feeding interventions were added. With or without formula feeding, low cost antiretroviral interventions were likely to save lives and money. Interventions that allowed breast feeding early on, to be replaced by formula feeding at 4 or 7 months, seemed likely to save fewer lives and offered poorer value for money.

CONCLUSIONS

Antiretroviral interventions are probably cost effective across a wide range of settings, with or without formula feeding interventions. The appropriateness of formula feeding was highly cost effective only in settings with high seroprevalence and reasonable levels of child survival and dangerous where infant mortality was high or the protective effect of breast feeding substantial. Pilot projects are now needed to ensure the feasibility of implementation.