Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States of America.
PLoS One. 2022 Apr 7;17(4):e0266495. doi: 10.1371/journal.pone.0266495. eCollection 2022.
Vitamin A Supplementation (VAS) is a cost-effective intervention to decrease mortality associated with measles and diarrheal diseases among children aged 6-59 months in low-income countries. Recently, experts have suggested that other interventions like large-scale food fortification and increasing the coverage of measles vaccination might provide greater impact than VAS. In this study, we conducted a cost-effectiveness analysis of a VAS scale-up in three sub-Saharan African countries.
We developed an individual-based microsimulation using the Vivarium simulation framework to estimate the cost and effect of scaling up VAS from 2019 to 2023 in Nigeria, Kenya, and Burkina Faso, three countries with different levels of baseline coverage. We calibrated the model with disease and risk factor estimates from the Global Burden of Disease 2019 (GBD 2019). We obtained baseline coverage, intervention effects, and costs from a systematic review. After the model was validated against GBD inputs, we modeled an alternative scenario where we scaled-up VAS coverage from 2019 to a level that halved the exposure to lack of VAS in 2023. Based on the simulation outputs for DALYs averted and intervention cost, we determined estimates for the incremental cost-effectiveness ratio (ICER) in USD/DALY.
Our estimates for ICER are as follows: $860/DALY [95% UI; 320, 3530] in Nigeria, $550/DALY [240, 2230] in Kenya, and $220/DALY [80, 2470] in Burkina Faso. Examining the data for DALYs averted for the three countries over the time span, we found that the scale-up led to 21 [5, 56] DALYs averted per 100,000 person-years in Nigeria, 21 [5, 47] DALYs averted per 100,000 person-years in Kenya, and 14 [0, 37] DALYs averted per 100,000 person-years in Burkina Faso.
VAS may no longer be as cost-effective in low-income regions as it has been previously. Updated estimates in GBD 2019 for the effect of Vitamin A Deficiency on causes of death are an additional driver of this lower estimate of cost-effectiveness.
在低收入国家，维生素 A 补充（VAS）是一种具有成本效益的干预措施，可以降低 6-59 个月儿童因麻疹和腹泻疾病导致的死亡率。最近，专家们认为，其他干预措施，如大规模食物强化和增加麻疹疫苗接种覆盖率，可能比 VAS 更具影响力。在这项研究中，我们对撒哈拉以南非洲的三个国家进行了 VAS 扩大规模的成本效益分析。
我们使用 Vivarium 模拟框架开发了一个基于个体的微观模拟，以估计 2019 年至 2023 年期间在尼日利亚、肯尼亚和布基纳法索扩大 VAS 规模的成本和效果，这三个国家的基线覆盖率水平不同。我们使用 2019 年全球疾病负担（GBD 2019）的疾病和风险因素估计值对模型进行了校准。我们从系统评价中获得了基线覆盖率、干预效果和成本。在模型经过 GBD 输入验证后，我们模拟了一种替代方案，即在 2019 年将 VAS 覆盖率扩大到 2023 年将缺乏 VAS 的暴露减半的水平。根据模拟结果，我们确定了用于避免的残疾调整生命年（DALY）和干预成本的增量成本效益比（ICER）的估计值。
我们的 ICER 估计如下：尼日利亚为 860 美元/DALY [95% UI；320，3530]，肯尼亚为 550 美元/DALY [240，2230]，布基纳法索为 220 美元/DALY [80，2470]。在考察三个国家在整个时间段内避免的 DALY 数据时，我们发现扩大规模导致尼日利亚每 10 万人每年避免 21 [5，56] DALY，肯尼亚每 10 万人每年避免 21 [5，47] DALY，布基纳法索每 10 万人每年避免 14 [0，37] DALY。
VAS 在低收入地区可能不再像以前那样具有成本效益。2019 年全球疾病负担（GBD 2019）对维生素 A 缺乏症对死亡原因影响的最新估计是降低这一成本效益估计的另一个驱动因素。
