Cost-effectiveness of Vitamin A supplementation among children in three sub-Saharan African countries: An individual-based simulation model using estimates from Global Burden of Disease 2019

Abstract

Background 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. Methods 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. Findings 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. Conclusions 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.

Optimal Allocation of Antenatal and Young Child Nutrition Interventions: An Individual-Based GBD-Calibrated Microsimulation

“…We utilize Vivarium (17), a mature, open-source, Python-based simulation framework for our baseline health model. Published examples of models utilizing Vivarium can be found elsewhere (5,18,19). For this application, our model consists of a closed cohort of simulated individuals that we track across discrete time steps.…”

Comparing Three Evidence-Based Strategies to Reduce Cardiovascular Disease Burden:An Individual-Based Cardiometabolic Policy Simulation

“…23 Published examples of models utilizing Vivarium can be found elsewhere. [24][25][26] Simulated individuals, at each time step, are subject to the probability of a disease event, or health care event (appointment, medications prescribed, healthy individuals may experience CVD events, individuals experiencing CVD events may recover or die), which is modified by their other assigned attributes including age, sex, and cardiometabolic risk factor exposures. A high-level flow diagram can be seen in Figure 1, with a more detailed version as eFigure 1 in the supplement and medication effects on risk factors in eTables 2 and 3.…”

Novel and classical morbilliviruses: Current knowledge of three divergent morbillivirus groups

“…In infected individuals, nutritional status, stress, and other illnesses that weaken these responses are presumed to influence the disease severity. In measles, increased mortality due to low nutritional status is evident, and vitamin A administration is known to be effective in preventing severe disease 116 . Effects of nutritional status and infectious agents such as babesia have also been shown in CDV infection 117,118 .…”

“…In measles, increased mortality due to low nutritional status is evident, and vitamin A administration is known to be effective in preventing severe disease. 116 Effects of nutritional status and infectious agents such as babesia have also been shown in CDV infection. 117,118 Furthermore, pregnant women and animals may be more susceptible to infection and worsening of symptoms because of physiological changes in the immune system.…”