One world, one hope: the cost of providing antiretroviral therapy to all nations

HIV treatment as prevention: modelling the cost of antiretroviral treatment--state of the art and future directions

Policy discussions about the feasibility of massively scaling up antiretroviral therapy (ART) to reduce HIV transmission and incidence hinge on accurately projecting the cost of such scale-up in comparison to the benefits from reduced HIV incidence and mortality. We review the available literature on modelled estimates of the cost of providing ART to different populations around the world, and suggest alternative methods of characterising cost when modelling several decades into the future. In past economic analyses of ART provision, costs were often assumed to vary by disease stage and treatment regimen, but for treatment as prevention, in particular, most analyses assume a uniform cost per patient. This approach disregards variables that can affect unit cost, such as differences in factor prices (i.e., the prices of supplies and services) and the scale and scope of operations (i.e., the sizes and types of facilities providing ART). We discuss several of these variables, and then present a worked example of a flexible cost function used to determine the effect of scale on the cost of a proposed scale-up of treatment as prevention in South Africa. Adjusting previously estimated costs of universal testing and treatment in South Africa for diseconomies of small scale, i.e., more patients being treated in smaller facilities, adds 42% to the expected future cost of the intervention.

Use of routine data collected by the prevention of mother-to-child transmission program for HIV surveillance among pregnant women in Rwanda: opportunities and limitations

To compare HIV prevalence measured by antenatal clinics (ANC) sentinel surveillance and by the prevention of mother-to-child transmission (PMTCT) program in Rwanda. We compared HIV prevalence from anonymous testing performed under ANC surveillance, and that measured from voluntary counselling and testing performed under the PMTCT program, in a random sample of the same population of pregnant women attending for their first antenatal visit at 29 ANC surveillance sites with a PMTCT program in 2007 in Rwanda. All of the 13,318 pregnant women recruited in the ANC surveillance accepted to participate in the PMTCT program. HIV prevalence measured by sentinel surveillance was 4.35% whereas that measured for 1873 pregnant women (out of the total sentinel population) by the PMTCT program was 3.49% (p=0.07). For 3% of the PMTCT population, HIV test results were missing from the counselling logbook versus 0.3% in the ANC laboratory logbooks. For 10 pregnant women, HIV test results were divergent between the PMTCT and the ANC laboratory logbooks. After missing data and errors were corrected, HIV prevalence results from PMTCT was 3.27% (significantly different from ANC surveillance: p =0.03). High uptake of PMTCT program among pregnant women was observed in Rwanda in 2007. HIV prevalence measured by the ANC surveillance and PMTCT program were significantly different. Poor performance in HIV testing practices and PMTCT/laboratories data management could explain this difference. Improvement in HIV testing practices and in PMTCT/laboratory data management are needed in order to use PMTCT data for HIV surveillance and to ensure good performance of all the package of care provided by the PMTCT program.

Impact of baseline viral load and adherence on survival of HIV-infected adults with baseline CD4 cell counts > or = 200 cells/microl

BACKGROUND

Baseline plasma HIV RNA levels > 100 000 copies/ml have been associated with elevated mortality rates after the initiation of HAART. There is uncertainty regarding the optimal strategy for patients with high plasma HIV RNA but CD4 cell count > or = 200 cells/microl.

OBJECTIVE

To evaluate the impact of baseline plasma HIV RNA on survival among patients with CD4 cell counts > or = 200 cells/microl.

METHODS

Patients were stratified by plasma HIV RNA, CD4 cell count and adherence level. Mortality rates were evaluated using Kaplan-Meier methods and Cox regression.

RESULTS

Among 1166 patients initiating HAART with a CD4 cell count > or = 200 cells/microl, a baseline HIV RNA > or = 100 000 copies/ml was statistically associated with elevated mortality among non-adherent patients (log-rank P = 0.032), but not for adherent patients (log-rank P = 0.690). In a multivariate Cox model comparing patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA < 100 000 copies/ml, the mortality rate was statistically similar among patients with a baseline CD4 cell count > or = 200 cells/microl and a baseline plasma HIV RNA > or = 100 000 copies/ml (relative hazard, 1.21; 95% confidence interval, 0.89-1.65; P = 0.232).

CONCLUSION

HIV RNA > or = 100 000 copies/ml was only associated with mortality among HIV-infected patients initiating HAART with CD4 cell counts > or= 200 cells/microl if the patients were non-adherent.

When to initiate antiretroviral therapy in HIV-1-infected adults: a review for clinicians and patients

One of the most controversial topics in the medical management of HIV disease is the optimal time to initiate highly active antiretroviral therapy (HAART) in HIV-1-infected adults. Premature exposure to antiretrovirals may precipitate early evolution of resistance and unnecessary side-effects, whereas remaining off HAART until late in the course of HIV disease may lead to reduced therapeutic benefits and elevated mortality. The lack of a randomised clinical trial to consider this issue has resulted in ongoing revision of expert recommendations and substantial variability between international consensus guidelines regarding the optimal time to initiate therapy. Since this uncertainty is a source of unease for both patients and clinicians, we summarise the latest evidence regarding the optimal time to initiate HAART with consideration of the potential benefits and drawbacks of starting HIV treatment at the different levels presently recommended in leading consensus guidelines.

Field Assessment of Generic Antiretroviral Drugs: A Prospective Cohort Study in Cameroon

Objective

To assess the effectiveness of generic anti-retroviral drugs in terms of survival and virological and immunological responses, as well as their tolerability and the emergence of viral resistance.

Methods

A total of 109 HIV-1-infected patients were enrolled in a prospective cohort study in Yaoundé, Cameroon. Available generic drugs were a fixed-dose combination (FDC) of zidovudine (ZDV) and lamivudine (3TC), an FDC of 3TC, stavudine (d4T) and nevirapine (NVP), and individual formulations of ZDV, 3TC and NVP.

Results

At baseline, the median CD4 cell count was 150/mm3 [interquartile range (IQR) 61–223] and median viral load was 5.4 log10 copies/ml (IQR 4.8–5.6); 78% of patients received ZDV/3TC/NVP and 22% received 3TC/d4T/NVP. Median follow-up was 16 months (IQR 11–23). The survival probability was high (0.92 at 12 months); plasma viral load declined by a median of 3.3 log10 copies/ml and 86.9% of the intention-to-treat population had viral load <400 copies/ml at 12 months; CD4 count had increased by a median of 106 cells/mm3 at 12 months; drug resistance rarely emerged (incidence rate 3.2 per 100 person-years); and the treatments were reasonably well-tolerated (incidence rate of severe adverse effects 7.8 per 100 person-years).

Conclusion

Together with previous pharmacological and clinical studies, this prospective study suggests that these generic antiretroviral drugs can be used in developing countries.

The cost of inaction on HIV transmission among injection drug users and the potential for effective interventions

Estimated and potential medical costs of treating patients infected with human immunodeficiency virus (HIV) in urban areas of high HIV prevalence have not been well defined. We estimated the total medical cost of HIV disease among injection drug users in Vancouver, British Columbia, Canada, assuming stable and increasing HIV prevalence. Total medical costs were estimated by multiplying the average lifetime medical cost per person by the number of HIV-infected individuals. We assumed the cost of each HIV infection to be 150,000 Canadian dollars, based on empirical data, and HIV prevalence estimates were derived from the Vancouver Injection Drug Users Study (VIDUS) and external data sources. By use of Monte Carlo simulation methodology, we performed sensitivity analyses to estimate total medical cost, assuming the HIV prevalence remained stable at 31% and under a scenario in which the prevalence rose to 50%. Expected medical expenditures based on current HIV prevalence levels were estimated as 215,852,613 Canadian dollars. If prevalence rises to 50% as reported in other urban centers, the median estimated medical cost would be approximately 348,935,865 Canadian dollars. This represents a difference in the total costs between the two scenarios of 133,083,253 Canadian dollars. Health planners should consider that predicted medical expenditures related to the HIV epidemic among injection drug users in our setting may cost an estimated 215,852,613 Canadian dollars. If funding cannot be found for appropriate prevention interventions and the prevalence rises to 50%, a further 133,083,253 Canadian dollars may be required.

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.

Access to voluntary counseling and testing for HIV in developing countries

The counseling that precedes and follows testing of subjects for HIV has become, quite unexpectedly, a focal point for assessment of the ethical propriety, availability, and appropriateness of health services during the AIDS epidemic. It can be anticipated that in the worst affected regions, Voluntary Confidential Counseling and Testing (VCCT) will be an integral component of "...access to comprehensive, essential, quality health care" which is WHO's goal of "Health for All" in the next century. The role, purpose, location, and methods of VCCT, which were reviewed at the previous Global Strategies Conference in 1997, are summarized. Currently understood objectives of VCCT include acceptance of the test, provision of care for HIV-infected individuals (particularly pregnant women), prevention of HIV transmission, and psychosocial support. Many countries in Africa are gradually instituting VCCT as part of their Primary Health Care package. For example "...access to care, counselling and support" for HIV/AIDS and STDs is one of the top 10 national priorities in South Africa. However, closer examination in the country reveals personnel and skill shortages, inability of half the primary health care (PHC) clinics to provide antenatal services, and HIV testing being offered in only 56%. Condom availability is generally good, but termination of pregnancy is undertaken in a bare 27% of hospitals. In other regions of Africa, VCCT is also deficient in many respects: medical services are often unavailable, support is absent, availability is restricted and there are few trained counselors. Consequently, workloads are heavy. Requirements for effective counseling will be listed. The global determinants of inequities in accessing VCCT, such as the GNP and the crushing debt burden borne by poor countries, are discussed. A third of women worldwide receive no antenatal care, and just 60% of the roughly 133 million annual births throughout the world are attended by trained health personnel. Even when VCCT services are available, they are often not acceptable. The overwhelming majority of African women appear to accept HIV testing, but only a proportion (59-61% in recent intervention trials) return for the results. Obstacles to be overcome for provision of VCCT services are identified. Evidence for a positive impact of VCCT services includes facilitated decision-making, acceptance and coping with HIV, improved family and community acceptance, increased condom use, and reduced gonorrhea rates and HIV transmission.

Healthcare Economics in HIV

In an era of cost-consciousness in the delivery of medical care, the economics of healthcare delivery for HIV-infected persons has been an area of active interest. Interested parties include the payors of HIV care, particularly public insurers, who are paying for an increasing amount of the overall cost of HIV care in the US; providers of care, many of whom are finding it increasingly difficult to provide HIV care in a capitated market; and those persons who are HIV-infected and increasingly caught in the economic turmoil of the HIV healthcare marketplace. This paper will review the literature published over the past year regarding the economics of healthcare for HIV in the US.

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.

Cost effectiveness of combination HIV therapy: 3 years later

Since 1997, expert panel guidelines for HIV care have recommended the use of combination antiretroviral therapy with at least 3 antiretroviral drugs. Several studies have examined the cost effectiveness of 3-drug combination antiretroviral regimens for the treatment of HIV infection. Analyses comparing a 3-drug protease inhibitor-containing regimen with a 1- or 2-drug non-nucleoside reverse transcriptase inhibitor regimen have consistently yielded incremental direct cost estimates ranging from $US10,000 to just over $US13,000 per year of life saved. In Western societies, such an incremental cost per year of life saved compares favourably with chronic therapy for other diseases and argues for the adoption of these drugs by payors and policy makers. The reason for this favourable cost-effectiveness ratio appears to be the decrease in opportunistic complications and hospitalisation associated with the effective use of combination antiretroviral therapy. Whether this initial benefit will be maintained is not yet known. Other comorbid illnesses such as hepatitis C or renal failure may subsequently increase the cost of HIV care, and some analyses suggest that resistance may develop to these drugs over the long term. In addition, studies are needed to assess the cost effectiveness of these therapies in developing countries where the expense of these drugs appears to put them out of reach. The collection and analysis of economic data will continue to be needed as newer HIV therapies become available and the HIV healthcare environment evolves. Quantifying medical care costs and calculating cost effectiveness involve assessing a moving target. Economic analyses of HIV infection must evolve in tandem with therapeutic changes to continue to be relevant to policy makers, payors of care, and those who provide and receive HIV care.

AIDS e pauperização: principais conceitos e evidências empíricas

O artigo discute as estratégias metodológicas que vêm sendo usadas na análise das inter-relações entre a vulnerabilidade ao HIV/AIDS e as desigualdades sociais, o preconceito e a marginalização, ressaltando-se as dificuldades metodológicas e as estratégias alternativas de investigação encontradas. Os principais achados da literatura internacional e brasileira foram revistos, enfatizando-se os temas: dimensões econômicas e macropolíticas da difusão do HIV/ AIDS; papel do consumo e da política de drogas; desigualdade e preconceito de gênero; desigualdade e preconceito racial/origem étnica; interação com as demais infecções sexualmente transmissíveis e sua relação com a pobreza; padrões de assistência à saúde e HIV/AIDS, em especial, acesso a anti-retrovirais; e violação dos direitos humanos. Apesar da restrita produção acadêmica brasileira e dos dilemas metodológicos envolvidos no exame das inter-relações entre variáveis psicossociais, culturais, sócio-políticas e vulnerabilidade ao HIV/AIDS, tais temas devem ser investigados em detalhe - considerando especificidades sociais e culturais do Brasil - e beneficiados pelas novas estratégias de pesquisa.

Costs of HIV medical care in the era of highly active antiretroviral therapy

OBJECTIVES

In the USA, Medicaid is the principal payer of the health care costs of patients with HIV infection. We wished to determine how the costs to Medicaid of patients in Maryland infected with HIV have changed in the setting of highly active antiretroviral treatment.

DESIGN

Observational cohort study.

METHODS

Analysis of combined economic and clinical data of patients from the Johns Hopkins HIV Service, the provider of primary and sub-specialty care for a majority of HIV-infected patients in the Baltimore metropolitan region. All patients were enrolled in Medicaid and received care longitudinally in Maryland from 1 January 1995 through 31 December 1997. Monthly Medicaid payments were calculated for all inpatient and outpatient services by fiscal year, CD4 cell count, and use of protease inhibitors.

RESULTS

For inpatients with a CD4 cell count < or = 50 x 10(6) cells/l, the total health care average monthly payments remained unchanged ($2629 in 1995, $2585 in 1997). Total mean monthly payments increased for those with a CD4 cell count > 50 x 10(6) cells/l (CD4 cell count 50-200 x 10(6) cells/l, $1172 in 1995 and $1615 in 1997, P < 0.05; CD4 cell count 201-500 x 10(6) cells/l, $1078 in 1995 and $1305 in 1997, P < 0.05). However, when data were stratified according to use of a protease inhibitor-containing regimen (used during approximately 50% of follow-up time in 1996-1997) it was found that hospital inpatient payments decreased significantly in all CD4 strata for patients on a protease inhibitor-containing regimen whereas pharmacy payments increased significantly. Inpatient payments associated with treating opportunistic illness were lower in 1996-1997 for patients receiving protease inhibitor therapy compared with those not receiving protease inhibitors. On balance, total health care payments tended to be slightly lower for patients receiving a protease inhibitor regimen.

CONCLUSION

Although protease inhibitor-containing antiretroviral regimens are being used by only about half of our Medicaid-insured patients, when they are used, there are significantly lower hospital inpatient and community care costs, as well as lower costs associated with the treatment of opportunistic illness. Even with the concurrent increase in their pharmacy costs, total health care costs were stable or slightly lower for these patients. We believe this is a favorable result suggesting a good clinical value being achieved without an increase in costs.