Costs of HIV+/AIDS at CD4+ counts disease stages based on treatment protocols

Cost-Effective Management of bEnign Positional Vertigo Using Canalith Repositioning

OBJECTIVE: The misdiagnosis and inappropriate treatment of benign positional vertigo have resulted in significant costs to the medical system. In the current medical-economic climate, there is an increased emphasis on cost control. Recent studies have shown that the canalith repositioning procedure (CRP) is effective; the next step is to show the impact of CRP in cost-effective management of benign positional vertigo.

METHODS: Forty-six of 100 patients who underwent CRP for benign positional vertigo responded to a survey regarding the financial impact of their disease. They were asked to subjectively estimate the sum of all disease-related expenses. Objective substantiation of this number was estimated by tabulating physician data, laboratory data, and failed treatment costs.

RESULTS: The subjective figure totaled $2684.74 per individual. Summation of the tangible objective figures yielded $2009.63 per patient, corroborating the subjective figure.

CONCLUSIONS: Because CRP is a relatively simple procedure that can obviate many wasted expenses in most patients, we believe that it is very cost-effective and should be incorporated into routine practice.

Impact of Protease Inhibitors on Drug Use and Cost for Hospital Patients with HIV

Objective:

To evaluate the impact of protease inhibitors on drug cost and frequency of admission-defining events for HIV-infected patients in the infectious diseases unit of F Houphouët Boigny Hospital in Marseilles, France, which provides conventional hospitalization and outpatient care.

Methods:

Data from a prospective eight-year study conducted from January 1, 1990, to December 31, 1997, were used. Data from nurse records were collected daily by a pharmacy resident. Statistical analyses were performed to compare 1997 data with previous years, since protease inhibitors were not available in France until March 1996.

Results:

A total of 1,558 inpatients, accounting for 2,717 admissions, participated in the study. From 1995 to 1997, we observed a decrease in the percentage of hospitalized patients compared with the total number of patients (48.8%). We also noticed a reduction in number of stays (52%) and mean duration of stays (from 16.06 ± 1.81 to 11.08 ± 1.80 d). Total drug cost in the inpatient care unit dropped by one-half (based on 100 patients/y). The number of hospital admissions and mean drug cost per stay also decreased for some opportunistic infections described as late complications of AIDS; at the same time, drug costs in the outpatient unit rose sharply.

Conclusions:

This study confirms recent advances in HIV management. Use of protease inhibitors has reduced the relative risk of opportunistic infections and cost of inpatient treatment. This reduction has been associated with a sharp cost increase for outpatient therapy, resulting from widespread use of protease inhibitors.

The cost of blood transfusions in cancer patients: a reanalysis of a Canadian economic evaluation

Background. Cancer patients undergoing chemotherapy are at an increased risk for anemia. Hence, they are high consumers of allogenic blood transfusions. In 1997, an economic evaluation was undertaken at the Princess Margaret Hospital to estimate the cost of a transfusion in cancer patients. The analysis relied on published costing information and on an internal review of patient resource utilization. Overall, the cost of a blood transfusion was estimated at Can$599. Since 1997, there have been some major changes in the management of Canada's blood supply and within the Princess Margaret Hospital.

Methods. In order to evaluate how these changes affected the cost of a transfusion in cancer patients, the original 1997 economic database was reanalyzed using updated 1999 costing information obtained from Canadian Blood Services (CBS) and from the Princess Margaret Hospital.

Results. The reanalysis suggested that the cost of a blood transfusion in cancer patients increased from Can$599 in 1997 to Can$731 in 1999. The major incremental costs responsible for this increase were additional screening tests, increased opportunity costs for donors and a modest rise in distribution and administration within the hospital. Costs that were no longer relevant in 1999 were the cost of treating transfusion-related infections.

Conclusions. These results support the findings of the original publication that a unit of blood is a highly resource intensive commodity which requires that each blood unit be used appropriately. Therefore, preventative strategies that would reduce the use of blood products have to be identified and implemented.

Do reduced inpatient costs associated with highly active antiretroviral therapy (HAART) balance the overall cost for HIV treatment?

In this article we analyse how the costs of treating patients with HIV infection in the US have changed over time, with an emphasis on the relationship between inpatient hospitalization costs and the costs of highly active antiretroviral therapy (HAART). We examine how HIV treatment modes have evolved by comparing the pre-HAART treatment period before 1996-7 with the subsequent use of HAART. We describe the sources of data on HIV healthcare service utilization, the costs of those services, and the differences between the annual costs of treating all patients with different stages of HIV and the lifetime costs of treating a person with HIV from the time of infection. The major question in estimating HIV treatment costs and their components is how to incorporate a complete set of services utilized from all providers of HIV treatment for a representative sample of patients with HIV. The literature reviewed varies significantly on both of these factors. Although the hospitalization of patients with HIV has been declining over the past 2 decades, this rate of decrease accelerated after the introduction of HAART. Initially, the declines in hospitalization and its associated costs were greater than the increases in drug therapy costs, so the annual total costs of treating patients with HIV decreased. However, subsequent studies failed to show decreases in overall annual treatment costs, given rising drug costs and increases in hospitalizations due to complications from, or resistance to, HAART and due to other diseases impacting HIV-infected patients. Although the lifetime costs of treating a person with HIV have also increased, this treatment has resulted in substantial gains in the length and quality of life for those living with HIV.

The cost and incidence of prescribing errors among privately insured HIV patients

BACKGROUND

With the rapid growth in the volume of HIV-related studies that address drug interactions, appropriate medication regimens, and when and how to alter drug regimens, it is challenging for physicians to stay informed. Physicians require knowledge about all drugs taken by HIV patients in order to assess accurately the benefits and risks of various drug combinations.

OBJECTIVE

To examine the cost and frequency of antiretroviral prescribing errors among a sample of privately insured patients with HIV disease.

METHODS

Data were obtained from the MarketScan Commercial Claims and Encounter Database created by the Medstat Group Inc. The MarketScan database contains claims data for inpatient care, outpatient care, physician services and prescription drugs in benefit plans sponsored by >50 large employers in the US. This study compared data from the 1999-2000 MarketScan database with those from the 2005 MarketScan database. The 2005 MarketScan database includes 12,226 HIV enrollees who received antiretroviral drugs. This study compared the claims experience of HIV patients who filled a prescription for a drug combination that is not recommended by the US Department of Health and Human Services Panel on Antiretroviral Guidelines for Adults and Adolescents with the claims experience of patients who did not receive such a prescription.

RESULTS

In the 1999-2000 database the most common inappropriate drug combination involved the co-administration of a protease inhibitor (PI) and the lipid-lowering drug simvastatin, and 1% of patients experienced this type of error. In the 2005 database, only 0.4% of patients (46 of 12,226) experienced an inappropriate combination of simvastatin and a PI while 5.3% of patients (644 of 12,226) received atazanavir and tenofovir without ritonavir (referred to herein as 'boosting errors'). Patients who experienced a boosting error incurred higher annual costs than patients who took ritonavir along with tenofovir and atazanavir ($US 20,927 vs $US 16,704). Because atazanavir was approved by the US FDA in June 2003, medication errors involving atazanavir were not relevant in 1999 and 2000. Overall, it was found that HIV patients were three times as likely to experience an inappropriate drug combination in 2005 than they were in either 1999 or 2000 (5.9% vs 1.9%), and that this increase is attributable to boosting errors. In addition, the prevalence rate of HIV in the 2005 MarketScan database was almost triple that in the 1999 MarketScan database (0.14% vs 0.05%).

CONCLUSION

This study indicates that those who provide care to HIV patients must be vigilant in their efforts to provide patients with a drug therapy regimen that minimizes the chance of an adverse reaction and maximizes the potential to control viral replication.

Cost-effectiveness of voluntary HIV screening in Russia

Russia has one of the world's fastest growing HIV epidemics, and HIV screening has been widespread. Whether such screening is an effective use of resources is unclear. We used epidemiologic and economic data from Russia to develop a Markov model to estimate costs, quality of life and survival associated with a voluntary HIV screening programme compared with no screening in Russia. We measured discounted lifetime health-care costs and quality-adjusted life years (QALYs) gained. We varied our inputs in sensitivity analysis. Early identification of HIV through screening provided a substantial benefit to persons with HIV, increasing life expectancy by 2.1 years and 1.7 QALYs. At a base-case prevalence of 1.2%, once-per-lifetime screening cost $13,396 per QALY gained, exclusive of benefit from reduced transmission. Cost-effectiveness of screening remained favourable until prevalence dropped below 0.04%. When HIV-transmission-related costs and benefits were included, once-per-lifetime screening cost $6910 per QALY gained and screening every two years cost $27,696 per QALY gained. An important determinant of the cost-effectiveness of screening was effectiveness of counselling about risk reduction. Early identification of HIV infection through screening in Russia is effective and cost-effective in all but the lowest prevalence groups.

The economic burden of HIV in the United States in the era of highly active antiretroviral therapy: evidence of continuing racial and ethnic differences

BACKGROUND

Assessing the economic burden of HIV/AIDS can help to quantify the effect of the epidemic on a population and assist policy makers in allocating public health resources.

OBJECTIVE

To estimate the economic burden of HIV/AIDS in the United States and provide race/ethnicity-specific estimates.

METHODS

We conducted an incidence-based cost-of-illness analysis to estimate the lifetime cost of HIV/AIDS resulting from new infections diagnosed in 2002. Data from the HIV/AIDS Reporting System of the Centers for Disease Control and Prevention were used to determine stage of disease at diagnosis and proportion of cases by race/ethnicity. Lifetime direct medical costs and mortality-related productivity losses were estimated using data on cost, life expectancy, and antiretroviral therapy (ART) use from the literature.

RESULTS

The cost of new HIV infections in the United States in 2002 is estimated at $36.4 billion, including $6.7 billion in direct medical costs and $29.7 billion in productivity losses. Direct medical costs per case were highest for whites ($180,900) and lowest for blacks ($160,400). Productivity losses per case were lowest for whites ($661,100) and highest for Hispanics ($838,000). In a sensitivity analysis, universal use of ART and more effective ART regimens decreased the overall cost of illness.

CONCLUSION

Direct medical costs and productivity losses of HIV/AIDS resulting from infections diagnosed in 2002 are substantial. Productivity losses far surpass direct medical costs and are disproportionately borne by minority races/ethnicities. Our analysis underscores economic benefits of more effective ART regimens and universal access to ART.

Neuropsychiatric disorders in HIV infection: impact of diagnosis on economic costs of care

BACKGROUND

HAART is associated with a growing prevalence of HIV-associated neuropsychiatric disorders (NPD) despite improved overall survival.

OBJECTIVE

To investigate the added direct costs of medical care for patients with and without NPD.

METHODS

Nine dimensions of patient-specific costs [as costs per patient per month (CPM)] were followed prospectively between 1997 and 2003 in a community-based HIV/AIDS clinic for HIV-1-seropositive patients with a diagnosis of NPD (n = 188) and without (n = 153). Patients with NPD were stratified into subgroups of cognitive impairment (CI), peripheral neuropathies (PN), or other neuropsychiatric disorders (OND).

RESULTS

Compared with the non-NPD group ($916), patients in the NPD group showed an increased mean CPM during the 12-month intervals immediately preceding and subsequently following NPD diagnosis [$1371 (P < 0.001) and 1463 US dollars (P < 0.001), respectively], but not at 18 months prior to diagnosis (1061 US dollars; P > 0.05). Intragroup comparisons between 12 month post-diagnosis and 18 month pre-diagnosis showed a mean CPM increased of 67% (1613 US dollars; P < 0.001) with CI, 31% (1490 US dollars; P < 0.01) with PN, and 33% (1362 US dollars; P < 0.01) with OND. Increased numbers of clinic and physician visits, non-antiretroviral drugs and home care accounted for the higher mean CPM (P < 0.05) both pre-and post-diagnosis within the NPD group.

CONCLUSIONS

Neuropsychiatric disorders in patients with HIV/AIDS increase medical costs both before and after diagnosis, primarily owing to the management of the neuropsychiatric illness. Cost analyses offer useful measures of evolving patient needs, and provide a basis for allocation of healthcare resources.

Nonantiretroviral drug consumption by CD4 cell count in HIV-infected adults: a 5-year cohort study in Côte d'Ivoire

We followed a cohort of 592 HIV-infected adults during 1292 person-years in Abidjan before the highly active antiretroviral therapy (HAART) era. On the basis of the exhaustive monitoring of nonantiretroviral drugs actually delivered to the patients and of the real cost of drugs at the cohort center's pharmacy during the study period, we estimated the mean cost of drugs per person per year (MCPPY) overall, by drug characteristics, and by patients' baseline CD4 cell count. The MCPPY was dollar 198 US overall and dolalr 83 US, dollar 101 US, dollar 186 US, dollar 233 US, and dollar 459 US in patients with a baseline CD4 count > or = 500 cells/mm, 350 to 499 cells/mm, 200 to 349 cells/mm, 100 to 199 cells/mm, and <100 cells/mm, respectively. The most costly classes of drugs were the antibacterial (MCPPY dollar 30 US), the antifungal (dollar 16 US), and the analgesic (dollar 6 US) classes in patients with a baseline CD4 count > or = 500 cells/mm versus the antifungal (dollar 208 US), the antibacterial (dollar 49 US), and the antiparasitic (dollar 31 US) classes in patients with a baseline CD4 count <100 cells/mm. These data could be used in further cost-effectiveness analyses that seek to prioritize health interventions. Meanwhile, they roughly suggest that successful antiretroviral treatment, which would stabilize the CD4 count above 500 cells/mm, could reduce by 5-fold the cost of nonantiretroviral drugs in HIV-infected adults in Abidjan.

Cost-effectiveness of screening for HIV in the era of highly active antiretroviral therapy

BACKGROUND

The costs, benefits, and cost-effectiveness of screening for human immunodeficiency virus (HIV) in health care settings during the era of highly active antiretroviral therapy (HAART) have not been determined.

METHODS

We developed a Markov model of costs, quality of life, and survival associated with an HIV-screening program as compared with current practice. In both strategies, symptomatic patients were identified through symptom-based case finding. Identified patients started treatment when their CD4 count dropped to 350 cells per cubic millimeter. Disease progression was defined on the basis of CD4 levels and viral load. The likelihood of sexual transmission was based on viral load, knowledge of HIV status, and efficacy of counseling.

RESULTS

Given a 1 percent prevalence of unidentified HIV infection, screening increased life expectancy by 5.48 days, or 4.70 quality-adjusted days, at an estimated cost of 194 dollars per screened patient, for a cost-effectiveness ratio of 15,078 dollars per quality-adjusted life-year. Screening cost less than 50,000 dollars per quality-adjusted life-year if the prevalence of unidentified HIV infection exceeded 0.05 percent. Excluding HIV transmission, the cost-effectiveness of screening was 41,736 dollars per quality-adjusted life-year. Screening every five years, as compared with a one-time screening program, cost 57,138 dollars per quality-adjusted life-year, but was more attractive in settings with a high incidence of infection. Our results were sensitive to the efficacy of behavior modification, the benefit of early identification and therapy, and the prevalence and incidence of HIV infection.

CONCLUSIONS

The cost-effectiveness of routine HIV screening in health care settings, even in relatively low-prevalence populations, is similar to that of commonly accepted interventions, and such programs should be expanded.

Using simulation for AIDS policy modeling: benefits for HIV/AIDS prevention policy makers in Vienna, Austria

In spite of advanced therapies and the success of additional prevention programs, the HIV/AIDS epidemic still remains a challenge. Our paper refers academics, health care managers, and policy makers to the relevance of AIDS policy simulators in better decision-making. By highlighting the types of decisions AIDS policy models can support, we demonstrate the strategic role of AIDS policy simulators for the efficient and effective planning of scarce resources to fight the epidemic. For each type of decision, we then review exemplary AIDS policy simulators that have helped policy makers make better decisions. Finally, we present the benefits of an AIDS policy simulator for HIV/AIDS prevention policy makers in Vienna, Austria.

The direct cost and incidence of systemic fungal infections

OBJECTIVES

In this study we determined the incidence and direct inpatient and outpatient costs of systemic fungal infections (candidiasis, aspergillosis, cryptococcosis, histoplasmosis) in 1998.

METHODS

Using primarily the National Hospital Discharge Survey (NHDS) for incidence and the Maryland Hospital Discharge Data Set (MDHDDS) for costs, we surveyed four systemic fungal infections in patients who also had HIV/AIDS, neoplasia, transplant, and all other concomitant diagnoses. Using a case-control method, we compared the cases with controls (those without fungal infections with the same underlying comorbidity) to obtain the incremental hospitalization costs. We used the Student's t-test to determine significance of incremental hospital costs. We modeled outpatient costs on the basis of discharge status to calculate the total annual cost for systemic fungal infections in 1998.

RESULTS

For 1998, the projected average incidence was 306 per million US population, with candidiasis accounting for 75% of cases. The estimated total direct cost was $2.6 billion and the average per-patient attributable cost was $31,200. The most commonly reported comorbid diagnoses with fungal infections (HIV/AIDS, neoplasms, transplants) accounted for only 45% of all infections.

CONCLUSIONS

The cost burden is high for systemic fungal infections. Additional attention should be given to the 55% with fungal disease and other comorbid diagnoses.

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.

Cost-effectiveness of HIV counseling and testing in US prisons

The prevalence of human immunodeficiency virus (HIV) in correctional facilities is much higher than in the general population. However, HIV prevention resources are limited, making it important to evaluate different prevention programs in prison settings. Our study presents the cost-effectiveness of offering HIV counseling and testing (CT) to soon-to-be-released inmates in US prisons. A decision model was used to estimate the costs and benefits (averted HIV cases) of HIV testing and counseling compared to no CT from a societal perspective. Model parameters were HIV prevalence among otherwise untested inmates (1%); acceptance of CT (50%); risk for HIV transmission from infected individuals (7%); risk of HIV acquisition for uninfected individuals (0.3%); and reduction of risk after counseling for those infected (25%) and uninfected (20%). Marginal costs of testing and counseling per person were used (no fixed costs). If infected, the cost was $78.17; if uninfected, it was $24.63. A lifetime treatment cost of $186,900 was used to estimate the benefits of prevented HIV infections. Sensitivity and threshold analysis were done to test the robustness of these parameters. Our baseline model shows that, compared to no CT, offering CT to 10,000 inmates detects 50 new or previously undiagnosed infections and averts 4 future cases of HIV at a cost of $125,000 to prison systems. However, this will save society over $550,000. Increase in HIV prevalence, risk of transmission, or effectiveness of counseling increased societal savings. As prevalence increases, focusing on HIV-infected inmates prevents additional future infections; however, when HIV prevalence is less than 5%, testing and counseling of both infected and uninfected inmates are important for HIV prevention.

Longitudinal assessment of economic burden and clinical outcomes in acromegaly

OBJECTIVE

To determine costs and outcomes over time for surgical and various medical regimens in the management of patients with acromegaly.

METHODS

We studied a sample of 53 consecutive Canadian patients with acromegaly who underwent a transsphenoidal pituitary surgical procedure only (N = 27) or in conjunction with medical therapy (N = 26). Outcomes were analyzed as person-months spent in various health state outcomes, which were defined on the basis of growth hormone and insulin-like growth factor I levels. Costs are reported in 1998 Canadian dollars.

RESULTS

The mean duration of follow-up was 49 months. Of the 53 patients, 25 (47%) had microadenomas at admission. Patients spent as much as 65% of the time in "uncured" health states. Patients with less extensive disease had better outcomes. The mean annual cost per patient was $8,111 (95% confidence interval, $5,848 to $10,374). Medications were the largest contributor to overall cost (38%). Although per patient surgical costs themselves were high (ranging from approximately $2,800 to $9,200), when averaged over the 4 years the mean annual cost was approximately $2,400, less than the cost of medications. Treatment of macroadenomas cost more than treatment of microadenomas ($11,425 versus $4,442 annually). The treatment of acromegaly costs $14.7 million annually in Canada (95% confidence interval, $10.6 to $18.8 million) and, if patterns of care are similar, about $139 million annually in the United States.

CONCLUSION

Treatment of acromegaly is no more costly than therapy for other chronic diseases, especially those with a surgical component. Early diagnosis (at the stage of microadenoma) resulted in better outcomes and lower costs. Thus, from the standpoint of economics and well-being, a continued aggressive attitude toward screening programs and treatment of persistently active acromegaly seems warranted.

The cost effectiveness of combination antiretroviral therapy for HIV disease

BACKGROUND

Combination antiretroviral therapy with a combination of three or more drugs has become the standard of care for patients with human immunodeficiency virus (HIV) infection in the United States. We estimated the clinical benefits and cost effectiveness of three-drug antiretroviral regimens.

METHODS

We developed a mathematical simulation model of HIV disease, using the CD4 cell count and HIV RNA level as predictors of the progression of disease. Outcome measures included life expectancy, life expectancy adjusted for the quality of life, lifetime direct medical costs, and cost effectiveness in dollars per quality-adjusted year of life gained. Clinical data were derived from major clinical trials, including the AIDS Clinical Trials Group 320 Study. Data on costs were based on the national AIDS Cost and Services Utilization Survey, with drug costs obtained from the Red Book.

RESULTS

For patients similar to those in the AIDS Clinical Trials Group 320 Study (mean CD4 cell count, 87 per cubic millimeter), life expectancy adjusted for the quality of life increased from 1.53 to 2.91 years, and per-person lifetime costs increased from $45,460 to $77,300 with three-drug therapy as compared with no therapy. The incremental cost per quality-adjusted year of life gained, as compared with no therapy, was $23,000. On the basis of additional data from other major studies, the cost-effectiveness ratio for three-drug therapy ranged from $13,000 to $23,000 per quality-adjusted year of life gained. The initial CD4 cell count and drug costs were the most important determinants of costs, clinical benefits, and cost effectiveness.

CONCLUSIONS

Treatment of HIV infection with a combination of three antiretroviral drugs is a cost-effective use of resources.

The cost effectiveness of voluntary prenatal and routine newborn HIV screening in the United States

OBJECTIVE

To evaluate the cost effectiveness of voluntary prenatal and routine postnatal HIV screening in the cohort of pregnant women and newborns in the United States.

DESIGN

Cost-effectiveness analysis. We developed a decision model to analyze the cost effectiveness of enhanced prenatal screening and routine newborn screening for HIV. We also analyzed the incremental cost effectiveness of routine newborn screening when improved voluntary prenatal screening is already in place.

PARTICIPANTS

Analysis of the cohort of pregnant women and newborns in the United States.

INTERVENTIONS

Enhanced prenatal screening, or routine newborn screening for HIV.

MAIN OUTCOME MEASURES

Infections averted, life expectancy, costs, and incremental cost effectiveness.

RESULTS

Improved participation in voluntary prenatal HIV screening would result in an additional 1.1 million women being screened annually, would identify an additional 527 HIV-infected mothers annually, would avert 150 infections in newborns, and would cost $8,900 U.S. per life-year gained. Routine newborn HIV screening would test 3.9 million infants annually, would identify 1061 HIV-infected mothers, would avert 266 infections in newborns, and would cost $7,000 U.S. per life-year gained. If improved voluntary prenatal screening is already in place, routine newborn screening would avert an additional 135 infections in newborns, at an incremental cost of $10, 600 U.S. per life-year gained. The screening programs are likely to be cost effective over a wide range of assumptions regarding key factors in the analysis.

CONCLUSIONS

Improved voluntary prenatal HIV screening of women and routine screening of newborns are cost effective. Routine newborn screening becomes less attractive as the rate of voluntary prenatal screening increases. Improved participation in voluntary prenatal screening has the added benefit that mothers maintain their right to determine whether they are tested for HIV.

Cost effectiveness of human immunodeficiency virus postexposure prophylaxis for healthcare workers

OBJECTIVE

The United States Public Health Service (USPHS) published recommendations for human immunodeficiency virus (HIV) postexposure prophylaxis (PEP) of healthcare workers in May 1998. The aim of this study was to analyse the cost effectiveness of the USPHS PEP guidelines.

DESIGN AND SETTING

This was a modelling study in the setting of the US healthcare system in 1989. The analysis was performed from the societal perspective; however, only HIV healthcare costs were considered and health-related losses of productivity were not included.

METHODS

A decision tree incorporating a Markov model was created for 4 PEP strategies: the current USPHS recommendations, triple drug therapy, zidovudine monotherapy or no prophylaxis. A probabilistic sensitivity analysis using a Monte Carlo simulation was performed. Confidence intervals (CIs) around cost-effectiveness estimates were estimated by a bootstrapping method.

RESULTS

The costs (in 1997 US dollars) per quality-adjusted life-year (QALY) save by each strategy were as follows: monotherapy $US688 (95% CI: $US624 to $US750); USPHS recommendations $US5211 (95% CI: $US5126 to $US5293); and triple drug therapy $US8827 (95% CI: $US8715 to $US8940). The marginal cost per year of life saved was: USPHS recommendations $US81 987 (95% CI: $US80 437 to $US83 689); triple drug therapy $US970 451 (95% CI: $US924 786 to $US 1 014 429). Sensitivity testing showed that estimates of the probability of seroconversion for each category of exposure were most influential, but did not change the order of strategies in the baseline analysis. With the prolonged HIV stage durations and increased costs associated with recent innovations in HIV therapy, the marginal cost effectiveness of the USPHS PEP strategy was decreased to $US62 497/QALY saved. All 3 intervention strategies were cost effective compared with no postexposure prophylaxis.

CONCLUSIONS

Current USPHS PEP recommendations are marginally cost effective compared with monotherapy, but the additional efficacy of triple drug therapy for all risk categories is rewarded by only a small reduction in HIV infections at great expense. For the foreseeable future, assuming innovations in therapy that employ expensive drug combinations earlier in the HIV disease course to extend life expectancy and the increasing prevalence of HIV drug resistance, our model supports the use of the USPHS PEP guidelines.

The cost-effectiveness of expanded HIV counselling and testing in primary care settings: a first look

OBJECTIVE

To estimate the cost-effectiveness of approaches to expanded HIV counselling and testing.

DESIGN

A cost-effectiveness analysis.

SETTING

Primary care practices in the USA.

PARTICIPANTS

New patient visits.

INTERVENTIONS

Two approaches were examined: (i) requesting all patients to complete an HIV-risk screening instrument, with counselling as well as testing offered only to patients disclosing risk factors ('risk histories' option); and (ii) routine offering of voluntary testing to all patients, with consent obtained but no pre-test counselling ('routine testing').

MAIN OUTCOME MEASURES

The primary outcome was the cost per infection identified. We also examined: (i) the costs and numbers of infections averted if individuals change their risk behaviours; and (ii) the additional years of life and quality-adjusted life years (QALY) gained as a result of earlier HIV testing and treatment for infected individuals.

RESULTS

Routine testing is the most cost-effective approach to identifying infected individuals at an incremental cost of US$4200 per infection identified. Although using risk histories is more costly and less effective than routine testing, it becomes similarly cost-effective using plausible ranges for sensitivity analyses. If at least 10% of HIV-positive individuals change their behavior, both routine testing and using risk histories would save money. If testing identifies infected individuals one year earlier than they otherwise would have been diagnosed, routine testing would cost US$22000 per QALY gained.

CONCLUSION

Routine testing is the most cost-effective approach to identifying new HIV infections. However, using risk histories may be similarly cost-effective under various assumptions. Both routine testing and using risk histories are more cost-effective than current practices.

Cost effectiveness of epoetin-alpha to augment preoperative autologous blood donation in elective cardiac surgery

OBJECTIVE

The objective of this study was to assess the cost effectiveness of using epoetin-alpha (erythropoietin) to augment preoperative autologous donation (PAD) of blood prior to elective cardiac surgery.

DESIGN AND SETTING

We designed a decision-analytic model incorporating the risk of receiving allogeneic blood, the costs of blood products, the likelihood of developing transfusion-related diseases, the costs of transfusion-related diseases and their impact on life expectancy, and the effect of epoetin-alpha on the probability of transfusion.

INTERVENTIONS

The efficacy of epoetin-alpha was derived from data from a meta-analysis of published randomised trials comparing the use of epoetin-alpha to augment PAD with the use of PAD alone. Estimates for the other parameters were obtained by a systematic review of the literature.

MAIN OUTCOME MEASURES AND RESULTS

The use of epoetin-alpha reduced the proportion of patients receiving allogeneic transfusions by 60% (from 31.6 to 12.7%). However, this led to only a modest benefit of 0.000035 life years gained per patient and an incremental cost per life year gained of $Can44.6 million (1998 Canadian dollars). A detailed sensitivity analysis confirmed that the cost-effectiveness ratio was larger than that which is generally considered acceptable.

CONCLUSIONS

Our study indicates that the use of epoetin-alpha to reduce perioperative allogeneic transfusions in cardiac surgery is not cost effective.

HIV transmission and the cost-effectiveness of methadone maintenance

OBJECTIVES

This study determined the cost-effectiveness of expanding methadone maintenance treatment for heroin addiction, particularly its effect on the HIV epidemic.

METHODS

We developed a dynamic epidemic model to study the effects of increased methadone maintenance capacity on health care costs and survival, measured as quality-adjusted life-years (QALYs). We considered communities with HIV prevalence among injection drug users of 5% and 40%.

RESULTS

Additional methadone maintenance capacity costs $8200 per QALY gained in the high-prevalence community and $10,900 per QALY gained in the low-prevalence community. More than half of the benefits are gained by individuals who do not inject drugs. Even if the benefits realized by treated and untreated injection drug users are ignored, methadone maintenance expansion costs between $14,100 and $15,200 per QALY gained. Additional capacity remains cost-effective even if it is twice as expensive and half as effective as current methadone maintenance slots.

CONCLUSIONS

Expansion of methadone maintenance is cost-effective on the basis of commonly accepted criteria for medical interventions. Barriers to methadone maintenance deny injection drug users access to a cost-effective intervention that generates significant health benefits for the general population.

Everyday and exotic foodborne parasites

Everyday foodborne parasites, which are endemic in Canada, include the protozoans Entamoeba histolytica, Giardia lamblia and Cryptosporidium parvum. However, these parasites are most frequently acquired through unfiltered drinking water, homosexual activity or close personal contact such as in daycare centres and occasionally via a food vehicle. It is likely that many foodborne outbreaks from these protozoa go undetected. Transmission of helminth infections, such as tapeworms, is rare in Canada because of effective sewage treatment. However, a common foodborne parasite of significance is Toxoplasma gondii. Although infection can be acquired from accidental ingestion of oocysts from cat feces, infection can also result from consumption of tissue cysts in undercooked meat, such as pork or lamb. Congenital transmission poses an immense financial burden, costing Canada an estimated $240 million annually. Also of concern is toxoplasmosis in AIDS patients, which may lead to toxoplasmosis encephalitis, the second most common AIDS-related opportunistic infection of the central nervous system. Exotic parasites (ie, those acquired from abroad or from imported food) are of growing concern because more Canadians are travelling and the number of Canada's trading partners is increasing. Since 1996, over 3000 cases of Cyclospora infection reported in the United States and Canada were epidemiologically associated with importation of Guatemalan raspberries. Unlike toxoplasmosis, where strategies for control largely rest with individual practices, control of cyclosporiasis rests with government policy, which should prohibit the importation of foods at high risk.

Impact of zidovudine-based triple combination therapy on an AIDS drug assistance program

A static deterministic model was used to estimate the effect of the shift to a triple combination therapeutic standard on the annual AIDS Drug Assistance Program (ADAP) budget, total medical care expenditures, and population health outcomes for New York (NY) state ADAP enrollees. The model used opportunistic disease incidence data from the Multicenter AIDS Cohort Study (MACS) and other studies. Costs of treating opportunistic infections (OIs) and other HIV complications with each type of therapy were derived from treatment algorithms and standard unit costs. CD4+ cell counts were used as an index of need for OI prophylaxis and for determining OI incidence. Treatment with zidovudine-based combination therapy has been shown to increase CD4+ cell counts and reduce OI incidence. The model estimated that a change from monotherapy to triple therapy would have increased NY ADAP budget expenditures per enrollee by 115%. However, total medical system costs per ADAP enrollee (including ADAP costs) would decrease by 0.4% in the base case as a result of reduction in OIs and other HIV sequelae and associated costs. Results are sensitive to the assumed percentage of people taking combination therapy as well as to the assumptions made about the impact of the combination therapy on CD4+ cell count. Total ADAP budget impacts will depend on the growth in ADAP enrollment as a result of the availability of more effective therapies. In conclusion, this model demonstrates how access to newer, more effective HIV drug treatments can reduce the costs of treating OIs and provide major health benefits for ADAP enrollees.

Direct medical costs of chronic obstructive pulmonary disease: chronic bronchitis and emphysema

In this study we aimed to estimate direct medical costs of Chronic Obstructive Pulmonary Disease (COPD) by disease type; chronic bronchitis and emphysema. This study estimates direct costs in 1996 dollars using a prevalence approach and both aggregate and microcosting. A societal perspective is taken using prevalence, and multiple national, state and local data sources are used to estimate health-care utilization and costs. Chronic bronchitis and emphysema together account for $14.5 billion in annual direct costs. Inpatient costs are greater than outpatient and emergency costs ($8.3 vs. $7.8 billion) and hospital and medication costs account for most resources spent. The high prevalence of chronic bronchitis accounts for its larger total costs ($11.7 billion) compared with emphysema ($2.8 billion). Emphysema, which is more severe, has higher costs per prevalent case ($1341 vs. $816). Hospital stays account for the highest costs, $6.0 billion for chronic bronchitis and $1.9 billion for emphysema. The hospitalization rate, length of stay and average cost per prevalent case are higher for emphysema than for chronic bronchitis. Medication costs are the second highest cost category ($4.4 billion for chronic bronchitis, $0.693 billion for emphysema). The high hospitalization and low home care costs (0.2% of total) suggest underuse of home care and room to shift from acute to preventive care. More attention to healthcare management of chronic bronchitis and emphysema is suggested, and improving inhaler and anti-smoking compliance might be important targets.

Cost-effective management of benign positional vertigo using canalith repositioning

OBJECTIVE

The misdiagnosis and inappropriate treatment of benign positional vertigo have resulted in significant costs to the medical system. In the current medical-economic climate, there is an increased emphasis on cost control. Recent studies have shown that the canalith repositioning procedure (CRP) is effective; the next step is to show the impact of CRP in cost-effective management of benign positional vertigo.

METHODS

Forty-six of 100 patients who underwent CRP for benign positional vertigo responded to a survey regarding the financial impact of their disease. They were asked to subjectively estimate the sum of all disease-related expenses. Objective substantiation of this number was estimated by tabulating physician data, laboratory data, and failed treatment costs.

RESULTS

The subjective figure totaled $2684.74 per individual. Summation of the tangible objective figures yielded $2009.63 per patient, corroborating the subjective figure.

CONCLUSIONS

Because CRP is a relatively simple procedure that can obviate many wasted expenses in most patients, we believe that it is very cost-effective and should be incorporated into routine practice.

Post-exposure prophylaxis for HIV

The advent of preventive treatment for HIV highlights the urgent need for basic, clinical, and epidemiologic research targeting the pathogenesis and prevention of cutaneous and mucosal infection. In addition, the impact of HIV prophylaxis on the frequency of risk behaviors and antiretroviral drug resistance, especially in cities with high HIV prevalence, must be evaluated. In our view, the available data (albeit not definitive) are strong enough to support the provision of post-exposure prophylaxis in select cases of sexual and injection drug use exposure in addition to occupational exposures. However, post-exposure treatment should be used judiciously and only in the context of a comprehensive prevention program. Ultimately, primary exposure prevention, whether in health care facilities or in the community, is the most important strategy to prevent AIDS.

Cost-effectiveness of counseling and testing and partner notification: a decision analysis

OBJECTIVE

Counseling and testing and partner notification are effective HIV prevention strategies, but they can be resource intensive. This paper evaluates the cost-effectiveness of partner notification and counseling and testing offered in HIV and sexually transmitted disease (STD) clinics in preventing future HIV infections in the United States of America.

METHODS

Decision trees were developed from both societal and provider perspectives. The counseling and testing and partner notification models incorporate estimates of HIV prevalence, return rates for counseling, risk of HIV transmission within 1 year, and the effectiveness of counseling. Cost estimates for counseling and testing and partner notification programs and lifetime treatment cost of HIV for the United States of America were obtained from published literature. Extensive sensitivity analyses of model parameters were conducted.

RESULTS

For a cohort of 10,000 individuals at a clinic with an HIV seroprevalence of 1.5%, we estimate that counseling and testing prevents eight HIV infections and saves society almost $1,000,000. We estimate that partner notification for the 113 infected persons identified by counseling and testing, prevents another 1.2 HIV infections and saves an additional $181,000. To the provider (HIV and STD clinics), this translates to a cost of $32,000 per case prevented by counseling and testing and an additional $28,000 for partner notification. Model results are most sensitive to assumptions of HIV prevalence, risk of transmission, and treatment cost of HIV.

CONCLUSIONS

Counseling and testing and partner notification are cost effective in preventing HIV transmission in this setting. This model can be adapted to assess the cost-effectiveness of counseling and testing and partner notification in other settings.

The changing pattern of admissions to a London hospital of patients with HIV: 1988-1997. Royal Free Centre for HIV Medicine

OBJECTIVE

To describe the changes over time in incidence of hospital admissions among patients with HIV, reasons for hospital admission, duration of stay, relationship with CD4 T-cell count and with antiretroviral treatment.

METHODS

The incidence of hospital admissions during each calendar year from 1988 to 1997 inclusive was calculated using a person-years analysis. In addition the proportion of patient follow-up spent in hospital and the impact of changing treatment regimens among all patients with HIV aged > or = 14 years and with at least one CD4 T-cell count seen at the Royal Free Hospital, London was also described.

RESULTS

A total of 1806 patients were investigated with median follow-up of 21.1 months. Among all patients, the proportion of follow-up time spent as an in-patient decreased from 3.9% in 1988 to 1.3% in 1997 (P = 0.0015; test for trend). Hospital admissions for any cause peaked during 1989 at 72.0 per 100 patient years of follow-up (PYFU) and was 28.5 per 100 PYFU during 1997 (P < 0.0001; test for trend). There was a statistically significant decline in the proportion of follow-up time spent as an in-patient among patients with CD4 T-cell counts of < 50 x 10(6)/l from > 30% before 1990 to < 5% during 1997 (P = 0.026; test for trend). Hospital admissions varied greatly according to treatment regimen; in 1996 and 1997 just 0.1% of follow-up time of patients on triple antiretroviral treatment regimens was spent as a hospital admission.

CONCLUSIONS

Admissions to hospital began falling before the introduction of combination therapy and declined strikingly during 1996 and 1997 following the introduction of highly active antiretroviral therapy. These results have important implications for future allocation of resources and for patient management.

Beyond the biomedical and behavioural: towards an integrated approach to HIV prevention in the southern African mining industry

While migrant labour is believed to play an important role in the dynamics of HIV-transmission in many of the countries of southern Africa, little has been written about the way in which HIV/AIDS has been dealt with in the industrial settings in which many migrant workers are employed. This paper takes the gold mining industry in the countries of the Southern African Development Community (SADC) as a case study. While many mines made substantial efforts to establish HIV-prevention programmes relatively early on in the epidemic, these appear to have had little impact. The paper analyses the response of key players in the mining industry, in the interests of highlighting the limitations of the way in which both managements and trade unions have responded to HIV. It will be argued that the energy that has been devoted either to biomedical or behavioural prevention programmes or to human rights issues has served to obscure the social and developmental dimensions of HIV-transmission. This argument is supported by means of a case study which seeks to highlight the complexity of the dynamics of disease transmission in this context, a complexity which is not reflected in individualistic responses. An account is given of a new intervention which seeks to develop a more integrated approach to HIV management in an industrial setting.

HIV Risk Behavior among Outpatients at a State Psychiatric Hospital: Prevalence and Risk Modeling

The purpose of this archival study was to determine the prevalence and correlates of HIV-related risk behavior among adults with a severe and persistent mental illness (SPMI). Hospital records at a public psychiatric hospital were reviewed to obtain data on demographic and psychiatric characteristics, sexual behavior, and substance use. Data were available from 889 (73%) of 1214 eligible outpatients. Of these 889 patients, 49% were sexually active, 52% used alcohol, and 18% used street drugs during the past year. Eleven percent were at high risk for HIV infection: 7% reported having 3 or more sexual partners, 3% had been infected with an STD, 3% had traded sex, and fewer than 1% had shared injection equipment. HIV-risk status was modeled with logistic regression using diagnosis, type of residence, drug and alcohol use, and demographic variables; five- and six-predictor models were derived for two HIV-risk indicators. A bootstrap simulation supported the reliability of each model. We conclude that approximately one-half of adults living with a SPMI are sexually active, and a minority engages in behaviors that increase risk of HIV infection. Routine screening for HIV risk in psychiatric settings can identify patients who may benefit from risk reduction programs.

Preventing Mycobacterium avium complex in patients who are using protease inhibitors: a cost-effectiveness analysis

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 $233000 to $239800. Ignoring time discounting and quality of life, the cost-effectiveness of rifabutin relative to no prophylaxis was $44300 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 $54300 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 10(6) cells/l per year, or the CD4 count was greater than 50 x 10(6) 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 10(6) 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.

Cost-effectiveness analysis comparing liposomal anthracyclines in the treatment of AIDS-related Kaposi's sarcoma

Liposomal formulations have been shown to alter the efficacy and toxicity profiles of anthracylines for patients with HIV-related advanced Kaposi's sarcoma (KS). Using decision-analysis models, the costs and cost-effectiveness of the two U.S. Food and Drug Administration (FDA)-approved liposomal formulations of these agents were estimated. Estimates of costs, effectiveness, and cost-effectiveness were derived from clinical trial data of separate, randomized phase III trials of pegylated liposomal doxorubicin (20 mg/m2 every 3 weeks) and liposomal daunorubicin (40 mg/m2 every 2 weeks). Clinical response rates were 59% for pegylated liposomal doxorubicin and 25% for liposomal daunorubicin. Despite higher acquisition costs for pegylated liposomal doxorubicin, total estimated costs of treatment for KS and chemotherapy-related hematologic toxicities were similar ($7,066 U.S. compared with $6,621 U.S. for liposomal daunorubicin). Cost-effectiveness profiles, defined as average costs per responder, favored pegylated liposomal doxorubicin ($11,976 U.S./responder versus $26,483 U.S./responder for liposomal daunorubicin), reflecting the higher reported response rate in the phase III trial. Sensitivity analyses suggested that the costs and cost-effectiveness results would not differ markedly when evaluated over a range of assumptions, including response rate, neutropenia rate, and dosage variations.

Updates of cost of illness and quality of life estimates for use in economic evaluations of HIV prevention programs

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.

Cost-utility analysis of prophylactic treatment with oral ganciclovir for cytomegalovirus retinitis

OBJECTIVE

Cytomegalovirus (CMV) retinitis is a relatively common opportunistic infection in late-stage HIV disease, causing significant morbidity and mortality. Prophylactic use of oral ganciclovir has recently been shown to decrease the incidence of CMV retinitis but is relatively expensive and may not be very well tolerated by many patients. We performed a decision analysis to assess the cost-effectiveness of prophylactic oral ganciclovir therapy.

METHODS

A decision analysis using a Markov approach compared absence of prophylaxis and prophylaxis with oral ganciclovir. Estimates of effectiveness of prophylaxis and costs of illness were obtained from published literature. Drug costs were based on national average wholesale prices. All health care costs were based on 1996 U.S. dollars. Sensitivity analyses were done over ranges of estimates of cost and effectiveness.

RESULTS

Using our baseline estimates of cost and effectiveness, use of oral ganciclovir prophylaxis in patients with CD4 counts <50 cells/mm3 would be associated with average lifetime health care costs of $104,746, compared with $90,985 for no prophylaxis. Using oral ganciclovir, the average quality-adjusted life-years (QALYs) would be 2.05, and the CMV retinitis-free life-years would be 1.64, compared with 1.87 and 1.27, respectively, for no prophylaxis. The incremental cost-utility of oral ganciclovir is $76,676 per year of life saved and $37,542 per year of additional CMV retinitis-free life. Oral ganciclovir would become more cost-effective relative to no prophylaxis if the probability of CMV retinitis while taking oral ganciclovir declined. Oral ganciclovir would be less cost-effective if the cost of treating CMV retinitis declines, if our estimates of quality of life are low, or if the overall incidence of CMV retinitis declines.

CONCLUSIONS

Oral ganciclovir is a less cost-effective approach than several other interventions used for HIV-disease prophylaxis. It would potentially become cost-effective if it is possible to target oral ganciclovir prophylaxis to patients who are most likely to benefit.

Costs to Medicaid of advancing immunosuppression in an urban HIV-infected patient population in Maryland

Human immunodeficiency virus (HIV) infection is increasingly an urban disease in the United States, and Medicaid is the principal payer of the health care costs of patients with HIV. We wished to determine the costs to Medicaid of patients in Maryland infected with HIV as immunosuppression progresses, and to determine how costs varied by demographic characteristics of the patient. We analyzed combined economic and clinical data in patients from the Johns Hopkins HIV Service, the provider of primary and 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 July 1992 to June 1995. Monthly Medicaid payments were calculated for all inpatient and outpatient services by sex, race, age, use of injecting drugs, CD4+ count (>500, 201-500, 51-200, < or =50 cells/mm3), several opportunistic diseases, and death. Lifetime costs were also calculated by use of a Markov simulation. During 13,174 person-months of follow-up in 606 patients, a total of $18,223,700 in Medicaid payments was made. Mean monthly payments ranged from $2,436 (SE $171) for patients with CD4+ counts < or =50 cells/mm3 to $1,015 (SE $177) for patients with CD4+ counts >500 cells/mm3. Mean monthly inpatient costs ranged from $1,355 (SE $131) for CD4+ counts < or =50 cells/mm3 and $617 (SE $164) for CD4- counts >500 cells/mm3. For those with CD4+ counts < or =50 cells/mm3, outpatient pharmacy costs averaged $515 (SE $57) monthly, second only to inpatient costs. In bivariate analysis, costs were significantly higher (p = .013) in men (mean $1696; SE $126) than in women (mean $1,208; SE $101), though the difference was not significant with multivariate adjustment. Cytomegalovirus retinitis was the most costly opportunistic disease, with mean monthly costs of $7,825 (SE $1,141) within the 6 mo after diagnosis. Within 6 mo of death, mean monthly costs are $4,600 (SE $424). Lifetime costs for treating an HIV-infected patient who presents with a CD4+ count >500 cells/mm3 are $133,500 over 8.3 years of life. We concluded that in the clinic where the analysis was done, average costs to Medicaid of treating patients increase more than two-fold as the CD4+ count declines from >500 cells/mm3 to < or =50 cells/mm3. Interventions that decrease hospitalization, opportunistic disease, and the costs of terminal care may be most likely to decrease overall costs. Demographic patient characteristics do not affect costs significantly when access to care is comparable.