Cost-effectiveness of antiviral drug therapy to reduce mother-to-child HIV transmission in sub-Saharan Africa

Objective: To assess the potential cost-effectiveness of short-course antiviral regimens to prevent mother-to-child transmission (MCT) of HIV in sub-Saharan Africa. Design: Cost-effectiveness analysis. Methods: No intervention was compared with three regimens of twice daily zidovudine and lamivudine: regimen A, starting at 36 weeks of gestation and continuing to 1 week postpartum; regimen B, from intrapartum through 1 week postpartum; and regimen C, intrapartum only. Model inputs were estimated from published and unpublished data. Absolute percentage reductions in HIV transmission extrapolated from zidovudine monotherapy trials were estimated at 12.4, 8.6 and 4.3% for regimens A, B, and C, respectively. Outcome measures were net costs to the public sector health-care system, cost per infection averted, and cost per disability-adjusted life-year (DALY) gained. Multiple sensitivity analyses were conducted. Results: Based on the hypothetical efficacy estimates, regimen C was the most cost-effective. For a cohort of 100 women with 15% HIV prevalence, net costs to the public sector health-care systems were estimated at US$ 3617 for regimen A, US$ 1667 for regimen B, and US$ 351 for regimen C. Regimen C had a cost of US$ 1129 per HIV infection averted and a cost of US$ 60 per DALY. Regimens B and A cost US$ 2680 and 5134 per infection averted and US$ 143 and 274 per DALY, respectively. Cost-effectiveness declined rapidly at efficacy below 10% or HIV prevalence below 7%. Results were very sensitive to antiviral drug costs. For example, at 20% of current prices, the cost per DALY for regimen A fell to US$ 64, and to about US$ 42 for regimens B and C. Conclusion: Antiviral therapy may be cost-effective compared with other health interventions if HIV prevalence is high, if clinical trials confirm estimated efficacies, and if drug prices are reduced. (C) 1998 Lippincott-Raven Publishers.