Clinical impact and cost-effectiveness of antiretroviral therapy in India: starting criteria and second-line therapy

Background: India has more than 5.7 million people infected with human immunodeficiency virus (HIV). In 2004, the Indian government began providing antiretroviral therapy (ART), and there are now an estimated 56 500 people receiving ART. Objective: To project the life expectancy, cost, and cost-effectiveness associated with different strategies for using ART in India, to inform treatment programs. Methods: We utilized an HIV disease simulation model, incorporating data on natural history, treatment efficacy, and costs of care from India. Input parameters for the simulated cohort included mean age 32.6 years and mean CD4 count 318 cells/mu l (SD 291 cells/mu l). We examined different criteria for starting and stopping ART with a first-line regimen of stavudine/lamivudine/nevirapine, and the impact of a second-line protease-inhibitor-basedregimen. Cost-effectiveness in US dollars peryear of life saved (US$/YLS) was compared incrementally among alternative starting, sequencing, and stopping criteria. Results: Discounted (undiscounted) mean survival ranged from 34.5 (37.5) months with no ART to 64.7 (73.6) months with one line of therapy initiated at CD4 < 350cells/mu l, to 88.9 (106.5) months with two lines of therapy initiated at CD4 < 350cells/mu l. Lifetime medical costs ranged from US$530 (no ART) to US$5430 (two ART regimens) per person. With one line of therapy, the incremental cost-effectiveness ratios ranged from US$430NLS to US$550NLS as the CD4 starting criterion was increased from CD4 < 250cells/mu l to < 350cells/mu l. Use of two lines of therapy had an incremental cost-effectiveness ratio of US$1880NLS compared with the use of first-line therapy alone. Results were sensitive to the costs of second-line therapy and criteria for stopping therapy. Conclusions: In India, antiretroviral therapy will lead to major survival benefits and is cost-effective by World Health Organization criteria. The availability of second-line regimens will further increase survival, but their cost-effectiveness depends on their relative cost compared with first-line regimens. (c) 2007 Lippincott Williams & Wilkins.