Cost-effectiveness of tenofovir as first-line antiretroviral therapy in India

Abstract

Background: World Health Organization guidelines for antiretroviral treatment (ART) in resource-limited settings recommend either stavudine or tenofovir as part of initial therapy. We evaluated the clinical outcomes and cost-effectiveness of first-line ART using tenofovir in India, compared with current practice using stavudine or zidovudine.

Methods: We used a state-transition model of human immunodeficiency virus (HIV) disease to examine strategies using different nucleoside reverse-transcriptase inhibitors, combined with lamivudine and nevirapine, compared with no ART: (1) stavudine, (2) stavudine with substitution by zidovudine after 6 months, (3) zidovudine, and (4) tenofovir. Data were from the Y. R. Gaitonde Centre for AIDS Research and Education in Chennai, India, and published studies. Results. Discounted mean per person survival was 36.9 months (40.2 months undiscounted) with no ART, 115.5 months (145.3) with stavudine-containing ART, 115.7 months (145.6) with stavudine and 6-month zidovudine substitution, 115.8 months (145.6) with zidovudine-containing ART, and 125.8 months (162.0) with initial tenofovir. Discounted lifetime medical costs were $610 with no ART and ranged from $5580 with stavudine-containing ART to $5720 with zidovudine-containing ART. Initial tenofovir had an incremental cost-effectiveness ratio of $670 per year of life saved, compared with no ART, and was more economically efficient than the other regimens.

Results: were most sensitive to variations in the costs of first-line tenofovir, access to additional ART after treatment failure, and quality of life adjustment.

Conclusions: Using tenofovir as part of first-line ART in India will improve survival, is cost-effective by international standards, and should be considered for initial therapy for HIV-infected patients in India.

Figure 1

Life expectancy impact of a two-way sensitivity analysis on the incidence of and mortality from nephrotoxicity among tenofovir recipients. The upper three lines represent nephrotoxicity from initial tenofovir; the lower lines represent initial stavudine and nephrotoxicity from tenofovir-containing second-line ART. Probabilities of nephrotoxicity are 1.6% ( or ), 8.0% ( or ), and 16.0% ( or ).

Figure 2

Results of a two-way sensitivity analysis on the cost of initial tenofovir as its cost is varied from the current cost of initial stavudine (US$7/month, left side of the figure), through the base case current cost of initial tenofovir (US$14/month), and up to US$100/month (shown up to $40/month). Results are shown for the base case, where two lines of ART are available ( ), and for the scenario in which only one line of ART is available ( ). For the two-line scenario, the costs of the tenofovir component of second-line ART were assumed to rise commensurate with first-line cost increases; thus, the cost of tenofovir-containing second-line ART was varied from $49-$142 (not shown). These cost-effectiveness results are reported compared to no ART. For the one-line scenario, as the cost of initial tenofovir increases, the incremental cost-effectiveness ratios are reported compared to no ART (for initial tenofovir costs of $7 and $10), and to initial stavudine-to-zidovudine (for costs greater than $10). ART: antiretroviral therapy; YLS: year of life saved; GDP: gross domestic product.