Garnett Geoff P, Herbeck Joshua T, Akullian Adam
TB & HIV Team, Bill & Melinda Gates Foundation, Seattle, Washington, USA.
Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, Washington, USA.
J Int AIDS Soc. 2025 May;28(5):e26494. doi: 10.1002/jia2.26494.
Over the course of the HIV pandemic, prevention and treatment interventions have reduced HIV incidence, but there is still scope for new prevention tools to further control HIV. Studies of the cost-effectiveness of HIV prevention tools are often done using detailed, "transmission-aware" models, but there is a role for simpler analyses.
We present equations to calculate the cost-effectiveness, budget impact and epidemiological impact of HIV prevention interventions including equations allowing for multiple interventions and heterogeneity in risk across populations. As HIV incidence declines, the number needed to cover to prevent one HIV acquisition increases. Along with the benefits of averting HIV acquisitions, the cost-effectiveness of HIV prevention interventions is driven by incidence, along with efficacy, duration and costs of the intervention. The budget impact is driven by cost, size of the population and coverage achieved, and impact is determined by the effective coverage of interventions. HIV incidence has declined in sub-Saharan Africa, making primary HIV prevention less cost-effective and decreasing the price at which new prevention products provide value. Heterogeneity in risk could in theory allow for focusing HIV prevention, but current screening tools do not appear to sufficiently differentiate risk in populations where they have been applied. The simple calculations shown here provide rough initial estimates that can be compared with more sophisticated transmission dynamic and health economic models.
Simple equations show how the observed declines in HIV incidence in sub-Saharan Africa make primary prevention tools less cost-effective. If we require prevention to be more cost-effective, either we need primary prevention tools to be used disproportionately by those most at risk of acquiring HIV, or they need to be less expensive.
在艾滋病流行过程中，预防和治疗干预措施降低了艾滋病发病率，但仍有新型预防工具进一步控制艾滋病的空间。对艾滋病预防工具成本效益的研究通常使用详细的“传播感知”模型，但简单分析也有其作用。
我们提出了用于计算艾滋病预防干预措施成本效益、预算影响和流行病学影响的公式，包括允许进行多种干预以及人群风险存在异质性的公式。随着艾滋病发病率下降，预防一例艾滋病感染所需覆盖的人数增加。除了避免感染艾滋病的益处外，艾滋病预防干预措施的成本效益还受发病率以及干预措施的效果、持续时间和成本驱动。预算影响受成本、人口规模和实现的覆盖率驱动，而影响则由干预措施的有效覆盖率决定。撒哈拉以南非洲地区的艾滋病发病率已下降，这使得艾滋病初级预防的成本效益降低，并降低了新型预防产品产生价值的价格。理论上，风险异质性可使艾滋病预防更具针对性，但目前的筛查工具在其应用的人群中似乎并未充分区分风险。此处展示的简单计算提供了粗略的初步估计，可与更复杂的传播动力学和卫生经济模型进行比较。
简单公式表明，撒哈拉以南非洲地区观察到的艾滋病发病率下降如何使初级预防工具的成本效益降低。如果我们要求预防措施更具成本效益，要么需要让最易感染艾滋病的人群更多地使用初级预防工具，要么这些工具需要更便宜。
