State AIDS Drug Assistance Programs: equity and efficiency in an era of rapidly changing treatment standards

Abstract

Background: The 54 state AIDS Drug Assistance Programs (ADAP) provide medications to HIV-infected persons with limited resources. Eligibility and coverage vary, raising concerns about health inequities.

Objective: To compare the relative clinical and economic performance of ADAP programs.

Research design: A state-transition simulation model of HIV disease was used to explore the clinical consequences and lifetime costs associated with selected state policies. Clinical data came from the Multicenter AIDS Cohort Study, AIDS Clinical Trials Group Protocol 320, and other published randomized trials. Cost data came from the national AIDS Cost and Services Utilization Survey, and the 1999 Red Book. ADAP data came from National Association of State and Territorial AIDS Directors reports and interviews.

Measures: Projected life expectancy, quality-adjusted life expectancy, total lifetime direct medical costs, cost-effectiveness in dollars per quality-adjusted life year (QALY) gained.

Results: ADAPs vary considerably in terms of formulary policies, health outcomes, expected costs, and cost-efficiency. Conservative projections, based on a cohort with starting mean CD4 count of 250 cells/microL, yield life expectancies ranging from 5.36 to 6.81 life years (4.69-6.01 quality-adjusted life years [QALYs]). Total per person lifetime direct medical costs range from $81,200 to $112,700; higher costs reflect increased spending on medications. Expected costs per QALY gained range from $7000 to $28,000. Under pessimistic assumptions regarding initial CD4 counts, drug efficacy, and discounting, the most comprehensive policy remains below $33,000/QALY.

Conclusions: Even the most comprehensive ADAPs constitute a cost-effective use of HIV care resources. A uniform, national ADAP formulary warrants consideration.