Option B+: the way forward for Malawi

Comparative cost-effectiveness of Option B+ for prevention of mother-to-child transmission of HIV in Malawi.

Tweya H, Keiser O, Haas AD, Tenthani L, Phiri S, Egger M, Estill J. AIDS. 2016 Mar 27;30(6):953-62. doi: 10.1097/QAD.0000000000001009.

Objective: To estimate the cost-effectiveness of prevention of mother-to-child transmission (MTCT) of HIV with lifelong antiretroviral therapy (ART) for pregnant and breastfeeding women ('Option B+') compared with ART during pregnancy or breastfeeding only unless clinically indicated ('Option B').

Design: Mathematical modelling study of first and second pregnancy, informed by data from the Malawi Option B+ programme.

Methods: Individual-based simulation model. We simulated cohorts of 10 000 women and their infants during two subsequent pregnancies, including the breastfeeding period, with either Option B+ or B. We parameterized the model with data from the literature and by analysing programmatic data. We compared total costs of antenatal and postnatal care, and lifetime costs and disability-adjusted life-years of the infected infants between Option B+ and Option B.

Results: During the first pregnancy, 15% of the infants born to HIV-infected mothers acquired the infection. With Option B+, 39% of the women were on ART at the beginning of the second pregnancy, compared with 18% with Option B. For second pregnancies, the rates MTCT were 11.3% with Option B+ and 12.3% with Option B. The incremental cost-effectiveness ratio comparing the two options ranged between about US$ 500 and US$ 1300 per DALY averted.

Conclusion: Option B+ prevents more vertical transmissions of HIV than Option B, mainly because more women are already on ART at the beginning of the next pregnancy. Option B+ is a cost-effective strategy for PMTCT if the total future costs and lost lifetime of the infected infants are taken into account.

Abstract access

Editor’s notes: Nearly a quarter of a million children acquire HIV from their mothers every year. Antiretroviral therapy (ART) in pregnant women greatly reduces the risk of mother-to-child HIV transmission to less than two percent. Malawi was the first country to introduce ‘Option B+’, a programme eliminating new HIV infections among children and keeping their mothers alive, in which all pregnant and breastfeeding women living with HIV start lifelong ART regardless of CD4 count or clinical staging. This study compares the cost-effectiveness of Option B+ in Malawi, with Option B, in which ART is recommended only for the duration of pregnancy or breastfeeding, unless the woman qualifies for ART for her own health. Both options have been recommended by World Health Organisation prevention of mother-to-child HIV transmission strategies.

The model simulated a cohort of 10 000 women pregnant for the first time, from conception to the time when the infants were two years old. The authors found that although the total costs of implementing Option B+ were higher than those of Option B, the former can reduce the costs of HIV care and treatment in the future by preventing new infections. The incremental cost-effectiveness ratio of Option B+ compared to Option B, ranged from USD 500 to USD 1300 per disability-adjusted life-years averted, depending on key assumptions around survival and care. The results support the implementation of Option B+ as it is likely to be a cost-effective strategy in the long term and the authors suggest it should be considered as the preferred strategy in low-income, high-fertility settings.

Like all models, this model has some limitations. It only considers women’s first two pregnancies, but the fertility rate in Malawi is high (5.5 births per woman). The model limits itself to mother-to-child HIV transmission, and does not take into account sexual transmission, which is likely to be lower in Option B+. Further research in these two areas would be worthwhile. The landscape is quickly changing, as World Health Organization guidelines now suggest testing and treatment strategies. However, until that policy is fully implemented and absorbed across the world, Option B+ will remain a key element in the HIV response.

  • share