Past Contributions

AIDS: Resource Needs for HIV/AIDS
B. Schwartländer, J. Stover, N. Walker, L. Bollinger, J. P. Gutierrez, W. McGreevey, M. Opuni, S. Forsythe, L. Kumaranayake, C. Watts, and S. Bertozzi. Science 2001 292(5526): p. 2434-2436
http://www.sciencemag.org/cgi/content/summary/292/5526/2434

PROFILE: Dollars and Cents vs. the AIDS Epidemic
Gretchen Vogel. Science 2001 292(5526): p. 2420-2422
http://www.sciencemag.org/cgi/content/summary/292/5526/2420

South Africa in Crisis on HIV/AIDS Treatment
Timothy Trengove Jones. Science 2001 292(5526): p. 2431b-2432b
http://www.sciencemag.org/cgi/content/full/292/5526/2431b

AIDS Patient Care STDS 2000 Dec;14(12):672 Related Articles, Books, LinkOut Costs decline with HAART.

AIDS 2000 Oct 20;14(15):2383-9 Related Articles, Books, LinkOut Cost effectiveness of expanded antenatal HIV testing in London. Postma MJ, Beck EJ, Hankins CA, Mandalia S, Jager JC, de Jong-van den Berg LT, Walters MD, Sherr L. Groningen University Institute for Drug Exploration/Groningen Research Institute of Pharmacy, The Netherlands.

BACKGROUND: Recently the Department of Health announced the introduction in England of voluntary universal HIV screening in early pregnancy to prevent vertical transmission. New data have shown the importance of HIV infection in infants born to mothers who were HIV-negative in early pregnancy and who acquired HIV later in pregnancy or during lactation. This requires consideration of repeat testing in late pregnancy and testing of partners of pregnant women (expanded antenatal HIV testing).

OBJECTIVE: To estimate cost effectiveness of expanded antenatal HIV testing in London (England) within the framework of universal voluntary HIV screening in early pregnancy.

DESIGN: Incremental cost-effectiveness analysis.

METHODS: Cost estimates of service provision for HIV-positive children and adults by stage of HIV infection were combined with estimates of health benefits for infants and parents and with costs of counselling and testing (testing costs). In a pharmacoeconomic model cost effectiveness was estimated for expanded antenatal HIV testing in London for universal and selective strategies.

RESULTS: Testing costs in the plausible range of pounds sterling 4 to pounds sterling 40 translate into favourable incremental cost-effectiveness estimates for expanded antenatal HIV testing in London which is already at low numbers of vertical transmissions averted per 100000 pregnant women who test HIV-negative in early pregnancy. Favourable cost effectiveness for universal expanded testing would require testing costs in the lower range, whereas selective expanded testing may produce favourable cost effectiveness at testing costs close to pounds sterling 40.

CONCLUSION: Based on pharmaco-economic considerations, the authors believe that implementation of expanded HIV testing in London should be considered.

J Acquir Immune Defic Syndr 2000 Jul 1;24(3):227-31 Related Articles, Books, LinkOut Economic evaluation of drug resistance genotyping for the adaptation of treatment in HIV-infected patients in the VIRADAPT study. Chaix C, Grenier-Sennelier C, Clevenbergh P, Durant J, Schapiro JM, Dellamonica P, Durand-Zaleski I. Public Health, Henri Mondor, AP-HP, Paris, France.

BACKGROUND: Costs of antiretroviral therapy for HIV-infected patients have increased at a time when most countries are attempting to contain health care costs. Part of this increase results from HIV drug resistance associated with virologic failure and a subsequent shift to more complex and costly therapies. Genotypic guided treatment is associated with better virologic outcome. However, it is not yet known whether it will be cost effective.

METHODS: We present here an economic evaluation based on the results from the VIRADAPT study, a prospective, open-label, randomized trial comparing patients assigned to standard of care (n = 43), versus genotypic guided treatment (n = 64) for 6 months. Total follow-up for the extended trial was 1 year. Costs were computed from the viewpoint of the health care system. Hospitalization data were retrieved from the VIRADAPT study case report forms, costs were estimated from the cost of the corresponding diagnosis-related groups derived from the French national cost data base: these were actual costs and not charges. Data on the volume of tests prescribed, drugs, and clinic visits were retrieved from the VIRADAPT study database. The unit costs of tests and clinic visits were determined using the French national Social Security reimbursement price; costing of drugs used were based upon purchase price by either retail pharmacies or hospitals. Genotyping using TruGene HIV-1 assay was estimated at $500 per test from manufacturer's data (all figures in this paper are expressed in U.S. dollars).

RESULTS: Total mean (standard deviation) yearly costs per patients were $20,412 (+/-$10, 129) in the standard of care group and $18,484 (+/-$9,652) in the genotyping group (p =.35). Drug costs represented 55% of total costs. There was a trend toward a decrease in drug costs in the genotyping arm (p =.07), the greatest reduction being in the decreased use of protease inhibitors in the genotyping arm. The additional expense of genotyping appeared to be offset by the savings obtained in drug costs.

CONCLUSION: In our study, the cost of drug resistance testing is offset by a reduced use of protease inhibitors and their attendant costs. Although not reaching statistical significance, this trend in the reduction of drug costs and drug use presents a great interest for future trials.

AIDS Care 2000 Jun;12(3):321-32 Related Articles, Books, LinkOut Cost-effectiveness of an HIV risk reduction intervention for adults with severe mental illness. Johnson-Masotti AP, Pinkerton SD, Kelly JA, Stevenson LY. Department of Psychiatry and Behavioral Medicine, Medical College of Wisconsin, Milwaukee 53202, USA. ajohnson@mcw.edu

Small-group HIV prevention interventions that focus on individual behavioural change have been shown to be especially effective in reducing HIV risk among persons with severe mental illness. Because economic resources to fund HIV prevention efforts are limited, health departments, community planning groups and other key decision-makers need reliable information on the cost and cost-effectiveness (not solely on effectiveness) of different HIV prevention interventions. This study used an economic evaluation technique known as cost-utility analysis to assess the cost-effectiveness of three related cognitive-behavioural HIV risk reduction interventions: a single-session, one-on-one intervention; a multi-session small-group intervention; and a multi-session small-group intervention that taught participants to act as safer sex advocates to their peers. For men, all three interventions were cost-effective, but advocacy training was the most cost-effective of the three. For women, only the single-session intervention was cost-effective. The gender differences observed here highlight the importance of focusing on gender issues when delivering HIV prevention interventions to men and women who are severely mentally ill.

Med Decis Making 2000 Jan-Mar;20(1):89-94 Related Articles, Books, LinkOut How HIV treatment advances affect the cost-effectiveness of prevention. Pinkerton SD, Holtgrave DR. Department of Psychiatry and Behavioral Medicine, Center for AIDS Intervention Research, Medical College of Wisconsin, Milwaukee 53202, USA. pinkrton@mcw.edu

OBJECTIVE: The cost-effectiveness of an HIV prevention program depends, in part, on its potential to avert HIV-related medical care costs. Recent advances in antiretroviral therapy have made HIV/AIDS treatment both more effective and more costly, which might make HIV prevention either more or less cost-effective. The objective of the present study was to explicate the relationship between the effectiveness and costs of HIV treatment and the cost-effectiveness of HIV prevention programs.

METHODS: A basic analytic framework was used to compare the cost-effectiveness of HIV prevention interventions with respect to different HIV/AIDS medical care scenarios. Algebra was used to calculate a cost-effectiveness threshold that distinguishes prevention programs that become more cost-effective when therapeutic advances simultaneously increase or decrease the cost and effectiveness of treatment from those that become less cost-effective. Recent estimates of the costs and consequences of combination antiretroviral therapy were used to illustrate the calculation method.

RESULTS: The advent of combination antiretroviral therapies for HIV has increased the cost-effectiveness of some, but not all, HIV prevention interventions.

CONCLUSIONS: Whether a particular prevention program becomes more or less cost-effective as a consequence of advancements in the medical treatment of HIV/AIDS depends upon the specific characteristics of both the program and the therapy.

Qual Life Res 1999 Sep;8(6):471-80 Related Articles, Books, LinkOut Economic methods for measuring the quality of life associated with HIV infection. Bayoumi AM, Redelmeier DA. Department of Medicine, University of Toronto, Canada. ahmed.bayoumi@utoronto.ca

BACKGROUND: Quality of life is measured as utilities for cost-effectiveness analyses.

OBJECTIVE: To test the adequacy of three common utility elicitation methods for individuals with Human Immunodeficiency Virus (HIV) disease.

MEASUREMENTS: HIV-positive participants (n = 75) rated three standardized health states (symptomatic HIV infection, minor AIDS defining illness, and major AIDS defining illness) with two utility elicitation methods (Standard Gamble [SG], and Time Trade-off [TTO]) and one value method (Visual Analog [VA]). Participants also rated their own health with one utility method (Health Utilities Index [HUI]) and one conventional quality of life method (Medical Outcomes Study--HIV Health Survey [MOS-HIV]).

RESULTS: For all states, SG and TTO scores ranged from near 0.00 (equivalent to death) to 1.00 (best possible quality of life). Mean scores for symptomatic HIV were similar with the SG (0.80) and TTO (0.81) but higher than with the VA (0.70). Similar results were observed for minor AIDS defining illnesses (0.65, 0.65, 0.46 respectively) and major AIDS defining illnesses (0.42, 0.44, 0.25 respectively). Discrepant SG and TTO scores were observed in many individuals and were not explained by demographic characteristics. As expected, HUI scores of an individual's own health were related to the disease state. Four of ten MOS-HIV subscales (overall health, physical functioning, role functioning, and pain) were also related to disease state. HUI scores were correlated with the MOS-HIV score for overall health and for all MOS-HIV subscales except health transition.

CONCLUSIONS: Mean utility scores for HIV-related health states elicited by the Standard Gamble and Time Trade-off were similar but a large degree of individual variation persists. Economic methods provide imprecise estimates of the quality of life associated with HIV infection.

J Occup Environ Med 1999 Sep;41(9):754-60 Related Articles, Books, LinkOut Cost-effectiveness of a post-exposure HIV chemoprophylaxis program for blood exposures in health care workers. Marin MG, Van Lieu J, Yee A, Bonner E, Glied S. UMD-New Jersey Medical School, Newark 07103, USA.

We performed a cost-effectiveness analysis of a post-exposure chemoprophylaxis program for health care workers who sustained exposures to blood. We analyzed a program of (1) treatment with zidovudine alone versus no treatment and (2) treatment with three-drug therapy versus no treatment. Assuming that 35% of exposures were to HIV-positive sources, the zidovudine regimen prevented 53 HIV seroconversions per 100,000 exposures, at a societal cost of $2.0 million per case of HIV prevented. The cost per quality-adjusted life year saved was $175,222. A three-drug chemoprophylactic therapy program (postulating 100% effectiveness and 35% source HIV positivity), prevented 66 seroconversions per 100,000 exposures, at a cost of $2.1 million per case of HIV prevented and $190,392 per quality-adjusted life year saved. Treating sources known to be HIV-positive and treating severe exposures were the most cost-effective strategies.

AIDS 1999 May 28;13(8):963-9 Related Articles, Books, LinkOut Costs of HIV medical care in the era of highly active antiretroviral therapy. Gebo KA, Chaisson RE, Folkemer JG, Bartlett JG, Moore RD. Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.

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 10⁶ cells/l, the total health care average monthly payments remained unchanged ($2,629 in 1995, $2,585 in 1997). Total mean monthly payments increased for those with a CD4 cell count > 50 x 10⁶ cells/l (CD4 cell count 50-200 x 10⁶ cells/l, $1,172 in 1995 and $1,615 in 1997, P < 0.05; CD4 cell count 201-500 x 10⁶ cells/l, $1,078 in 1995 and $1,305 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.

JAMA 1998 Dec 23-30;280(24):2088-93 Related Articles, Books, LinkOut Comment in: JAMA. 1999 Jun 9;281(22):2083-4 JAMA. 1999 Jun 9;281(22):2083; discussion 2084 Pretreatment evaluation of chronic hepatitis C: risks, benefits, and costs. Wong JB, Bennett WG, Koff RS, Pauker SG. Department of Medicine, New England Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA. john.wong@es.nemc.org

CONTEXT: Chronic hepatitis C (CHC) infection affects nearly 4 million people in the United States. Treatment with interferon alfa-2b has been limited by its cost and low likelihood of long-term response.

OBJECTIVE: To examine the cost-effectiveness of alternative pretreatment management strategies for patients with CHC.

DESIGN: Decision and cost-effectiveness analysis using a Markov model to examine prevalence of genotypes, viral load, and histological characteristics in relation to the sustained response rate with treatment. Data were based on a previously published decision model and a MEDLINE literature search for hepatitis C, biopsy, and liver from 1966 to 1996.

PATIENTS: A hypothetical population of patients with CHC infection and elevated serum alanine aminotransferase level.

INTERVENTIONS: Combinations of liver biopsy, genotyping, and quantitative viral load determination prior to a single 6-month course of interferon alfa-2b; empirical interferon treatment; and conservative management.

MAIN OUTCOME MEASURES: Proportion of sustained responders, lifetime costs, life expectancy, and quality-adjusted life expectancy.

RESULTS: Strategies involving hepatitis C virus (HCV) RNA testing had marginal cost-effectiveness ratios up to $4,400 per discounted quality-adjusted life-year gained but would miss up to 36% of sustained responders. Empirical interferon treatment had a marginal cost-effectiveness ratio of $12,400 per discounted quality-adjusted life-year gained and reached all potential sustained responders. Strategies involving liver biopsy were more expensive and would miss 6% of sustained responders and yield slightly lower life expectancies.

CONCLUSIONS: Routine liver biopsy before treatment with interferon increases the cost of managing patients with CHC without improving health outcomes. Using quantitative HCV RNA testing to guide therapy misses some potential sustained responders. Empirical interferon treatment has a marginal cost-effectiveness ratio within the bounds of other commonly accepted therapies and misses none of the sustained responders.

AIDS 1998 Aug 20;12(12):1503-12 Related Articles, Books, LinkOut Preventing Mycobacterium avium complex in patients who are using protease inhibitors: a cost-effectiveness analysis. Bayoumi AM, Redelmeier DA. Department of Medicine, University of Toronto, Canada.

BACKGROUND: Practice guidelines recommending Mycobacterium avium complex (MAC) prophylaxis for patients with HIV disease were based on clinical trials in which individuals did not receive protease inhibitors.

OBJECTIVE: To estimate the cost-effectiveness of strategies for MAC prophylaxis in patients whose treatment regimen includes protease inhibitors.

DESIGN: Decision analysis with Markov modelling of the natural history of advanced HIV disease. Five strategies were evaluated: no prophylaxis, azithromycin, rifabutin, clarithromycin and a combination of azithromycin plus rifabutin.

MAIN OUTCOME MEASURES: Survival, quality of life, quality-adjusted survival, health care costs and marginal cost-effectiveness ratios.

RESULTS: Compared with no prophylaxis, rifabutin increased life expectancy from 78 to 80 months, increased quality-adjusted life expectancy from 50 to 52 quality-adjusted months and increased health care costs from $233,000 to $239,800. Ignoring time discounting and quality of life, the cost-effectiveness of rifabutin relative to no prophylaxis was $44,300 per life year. Adjusting for time discounting and quality of life, the cost-effectiveness of rifabutin relative to no prophylaxis was $41500 per quality-adjusted life year (QALY). In comparison with rifabutin, azithromycin was associated with increased survival, increased costs and an incremental cost-effectiveness ratio of $54,300 per QALY. In sensitivity analyses, prophylaxis remained economically attractive unless the lifetime chance of being diagnosed with MAC was less than 20%, the rate of CD4 count decline was less than 10 x 10⁶ cells/l per year, or the CD4 count was greater than 50 x 10⁶ cells/l.

CONCLUSION: MAC prophylaxis increases quality-adjusted survival at a reasonable cost, even in patients using protease inhibitors. When not contraindicated, starting azithromycin or rifabutin when the patient's CD4 count is between 50 and 75 x 10⁶ cells/l is the most cost-effective strategy. The main determinants of cost-effectiveness are CD4 count, viral load, place of residence and patient preference.

To allocate limited economic and other resources for HIV prevention and treatment for maximum benefit, health policy planners and decision makers require accurate, current estimates of the lifetime costs of HIV-related illness and the impact of therapy on the quality of life of HIV-infected persons. These data are central input parameters to the economic evaluation methodology known as cost-utility analysis. The estimates available in the literature are already outdated, and this paper presents updated estimates of the projected lifetime health care costs associated with HIV disease in the United States and the number of quality-adjusted life years (QALYs) lost to HIV in light of recent advancements in HIV diagnostics and therapeutics. Results indicate that the lifetime cost of HIV medical care has grown from about $55,000 U.S. to more than $155,000 U.S., while the number of QALYs lost per case of HIV infection has decreased from 9.26 to 7.10, when discounted at a 5% annual rate. When these figures are discounted instead at the newly recommended 3% rate, lifetime costs rise to more than $195,000 U.S. and lost QALYs increase to 11.23. The net effect of these increases in the medical costs of care and treatment saved by averting an HIV infection and in QALYs makes HIV prevention a relatively more cost-effective strategy than other, non-HIV health-related programs.

Pharmacoeconomics 1997 Jul;12(1):54-66 Related Articles, Books, LinkOut Modelling the cost effectiveness of lamivudine/zidovudine combination therapy in HIV infection. Chancellor JV, Hill AM, Sabin CA, Simpson KN, Youle M. Glaxo Wellcome UK Ltd, Uxbridge, Middlesex, England. jc16268@ggr.co.uk

The use of combination antiretroviral therapy is supported by clinical evidence for its superiority over monotherapy. Lamivudine (3TC) has been studied in combination with zidovudine (ZDV) and is recommended for use specifically in combination therapy. With the associated increase in drug acquisition cost, the economics of combination therapy versus monotherapy warrant study. An economic evaluation was undertaken to compare 3TC/ZDV combination therapy with ZDV monotherapy, taking a UK public finance perspective. The cost effectiveness of each of the 2 treatments was estimated using a Markov model of progression through 3 HIV-positive disease states: (i) CD4 cells > 200 and < 500 cells/mm3; (ii) CD4 < 200 cells/mm3, non-AIDS; and (iii) AIDS to eventual death. Progression probabilities and life expectancy were derived from a cohort treated at Chelsea and Westminster Hospital in London, using data for 1987 to 1995, along with cost data for a ZDV intent-to-treat population for 1994 and 1995. The relative risk of progression for 3TC/ZDV compared with ZDV monotherapy was estimated from meta-analysis of 4 completed comparative trials. To predict the effect of 3TC/ZDV on life expectancy and lifetime costs, progression probabilities were adjusted by the relative risk statistic for the duration of treatment with 3TC/ZDV. On the basis of an estimated relative risk of progression of 0.509 (95% CI 0.365 to 0.710), treatment with 3TC/ZDV is predicted to yield an incremental cost-effectiveness ratio of Pounds 6276 (95% CI Pounds 5337 to Pounds 9075) per life year saved (discounted at 6% per year). Extensive sensitivity analyses were performed to test the effects of varying values of input parameters on the model results. Under reasonable assumptions, the predicted cost effectiveness of 3TC/ZDV combination therapy compares favourably with previously reported economic analyses of various HIV treatments.