Newer drugs and earlier treatment: impact on lifetime cost of care for HIV-infected adults

Abstract

Objective: To determine the component costs of care to optimize treatment with limited resources.

Design: We used the Cost-Effectiveness of Preventing AIDS Complications Model of HIV disease and treatment to project life expectancy and both undiscounted and discounted lifetime costs (2010 €).

Methods: We determined medical resource utilization among HIV-infected adults followed from 1998 to 2005 in northern France. Monthly HIV costs were stratified by CD4 cell count. Costs of CD4, HIV RNA and genotype tests and antiretroviral therapy (ART) were derived from published literature. Model inputs from national data included mean age 38 years, mean initial CD4 cell count 372 cells/μl, ART initiation at CD4 cell counts less than 350 cells/μl, and ART regimen costs ranging from €760 to 2570 per month.

Results: The model projected a mean undiscounted life expectancy of 26.5 years and a lifetime undiscounted cost of €535,000/patient (€320,700 discounted); 73% of costs were ART related. When patients presented to care with mean CD4 cell counts of 510 cells/μl and initiated ART at CD4 cell counts less than 500 cells/μl or HIV RNA more than 100,000 copies/ml, life expectancy was 27.4 years and costs increased 1-2%, to €546,700 (€324,500 discounted). When we assumed introducing generic drugs would result in a 50% decline in first-line ART costs, lifetime costs decreased 4-6%, to €514,200 (€302 ,800 discounted).

Conclusion: As HIV disease is treated earlier with more efficacious drugs, survival and thus costs of care will continue to increase. The availability in high-income countries of widely used antiretroviral drugs in generic form could reduce these costs.

Fig. 1. Components of annual cost of HIV care by CD4 count

Annual costs were higher when simulated patients had CD4 counts >500/µl than when they were 351–500/µl, because the majority of patients with CD4 counts >500/µl were on antiretroviral therapy (ART).

Fig. 2. Distribution of annual undiscounted cost to the health system of providing care to a cohort of 7,360 persons recently diagnosed with HIV, by disease stage

This figure shows results for three cohorts of simulated patients: (a) Presentation with advanced disease: patients presenting to care with advanced disease, defined as CD4 counts <200/µl or AIDS-defining disease (mean CD4 count, 97/µl); lifetime cost; lifetime cost was €513,200 (€322,500 discounted). (b) Base case: patients presenting to care with base case characteristics, similar to those of patients presenting to care in France in 2005 (mean CD4 count, 372/µl); lifetime cost was €535,000 (€320,700 discounted). (c) Early presentation: patients presenting to care early (mean CD4 count, 510/µl); lifetime cost was €534,800 (€313,000 discounted). Simulated patients in each of these cohorts initiated antiretroviral therapy (ART) at CD4 counts <350/µl or severe AIDS-defining disease. Undiscounted lifetime costs are similar in the base case and early disease groups, but discounted costs are €7,700 higher in the base case group. This substantial difference may be explained by the earlier deaths and thus decreased discounting of expensive end-of-life costs in the base case.