Economic Evaluation of Three-drug Antiretroviral Regimens for the Prevention of Mother to Child Transmission of HIV in Thailand: A Simulation Model

Abstract

         According to the Thai national prevention of mother-to-child transmission of HIV (PMTCT) guidelines, a combination of zidovudine-AZT and single dose nevirapine-sd-NVP is provided to HIV-infected women who have CD4 count > 200 cells/mm3. However, sd-NVP can cause drug resistance to NVP and other antiretroviral drugs in the same group. In many countries, use of threedrug
antiretroviral regimens is proved to be more effective and may reduce resistance development, although it is more costly. Therefore, an economic evaluation of the three-drug regimens, zidovudine plus lamivudine plus efavirenz AZT+3TC+EFV and zidouvudine plus lamivudine plus boosted lopinavir (lopinavir/ritonavir)—AZT+3TC+LPV/r, compared with AZT+sd-NVP was conducted using economic modeling to compare cost and effectiveness of each regimen. The total cost is categorized into cost of PMTCT program, cost of antiretroviral drug for postpartum women with drug resistance, cost of treatment for premature birth and cost of paediatric HIV treatment. AZT+sd- NVP had the cheapest program cost, followed by AZT+3TC+EFV and AZT+3TC+LPV/r, respectively. Nevertheless, AZT+sd-NVP generated the highest cost of treatment for drug resistance. As a result, three-drug regimens provided the lower total cost and produce the higher outcome in terms of Quality Adjusted Life Year-QALY than AZT+sd-NVP. AZT+3TC+EFV represented the most value
for money option. A policy recommendation should shift from AZT+sd-NVP to the utilization of three-drug regimens.
Key words: PMTCT, ARV, vertical transmission, mother-to-child transmission, HIV, three-drug regimen