Objective: The World Health Organization (WHO) recently changed its first-line antiretroviral treatment guidelines in resource-limited settings. The cost-effectiveness of the new guidelines is unknown.
Design: Comparative effectiveness and cost-effectiveness analysis using a model of HIV disease progression and treatment.
Methods: Using a simulation of HIV disease and treatment in South Africa, we compared the life expectancy, quality-adjusted life expectancy, lifetime costs, and cost-effectiveness of five initial regimens. Four are currently recommended by the WHO: tenofovir/lamivudine/efavirenz; tenofovir/lamivudine/nevirapine; zidovudine/lamivudine/efavirenz; and zidovudine/lamivudine/nevirapine. The fifth is the most common regimen in current use: stavudine/lamivudine/nevirapine. Virologic suppression and toxicities determine regimen effectiveness and cost-effectiveness.
Results: Choice of first-line regimen is associated with a difference of nearly 12 months of quality-adjusted life expectancy, from 135.2 months (tenofovir/lamivudine/efavirenz) to 123.7 months (stavudine/lamivudine/nevirapine). Stavudine/lamivudine/nevirapine is more costly and less effective than zidovudine/lamivudine/nevirapine. Initiating treatment with a regimen containing tenofovir/lamivudine/nevirapine is associated with an incremental cost-effectiveness ratio of $1045 per quality-adjusted life year compared with zidovudine/lamivudine/nevirapine. Using tenofovir/lamivudine/efavirenz was associated with the highest survival, fewest opportunistic diseases, lowest rate of regimen substitution, and an incremental cost-effectiveness ratio of $5949 per quality-adjusted life year gained compared with tenofovir/lamivudine/nevirapine. Zidovudine/lamivudine/efavirenz was more costly and less effective than tenofovir/lamivudine/nevirapine. Results were sensitive to the rates of toxicities and the disutility associated with each toxicity.
Conclusion: Among the options recommended by WHO, we estimate only three should be considered under normal circumstances. Choice among those depends on available resources and willingness to pay. Stavudine/lamivudine/nevirapine is associated with the poorest quality-adjusted survival and higher costs than zidovudine/lamivudine/nevirapine.