High-resolution spatial prediction of anemia risk among children aged 6 to 59 months in low- and middle-income countries.

backgroundAnemia, a severe condition among children associated with adverse health effects such as impaired growth, limited physical and cognitive development, and increased mortality risk, remains widespread, particularly in low- and middle-income countries. This study combines Demographic and Health Surveys data with remotely sensed climate, demographic, environmental, and geo-spatial information, creating a data set comprising about 750,000 observations on childhood anemia from 37 countries. It is used to provide high-resolution spatio-temporal estimates of all forms of childhood anemia between 2005 and 2020.

methodsEmploying full probabilistic Bayesian distributional regression models, the research accurately predicts age-specific and spatially varying anemia risks. These models enable the assessment of the complete distribution of hemoglobin levels. Additionally, this analysis also provides predictions at a high resolution, allowing precise monitoring of this indicator, aligned with Sustainable Development Goal (SDG) 2.

resultsThis analysis provides high-resolution estimates for all forms of anemia and reveals and identifies striking disparities within and between countries. Based on these estimates, the prevalence of anemia decreased from 65.0% [62.6%-67.4%] in sub-Saharan Africa and 63.1% [60.6%-65.5%] in South Asia in 2010 to 63.4% [60.7%-66.0%] in sub-Saharan Africa and 58.8% [56.4%-61.3%] in South Asia in 2020. This translates into approximately 98.7 [94.5-102.8] million and 95.1 [91.1-99.0] million affected children aged 6 to 59 months in 2020, respectively, making it a major public health concern.

conclusionsOur approach facilitates the monitoring of age-specific spatio-temporal dynamics and the identification of hotspots related to this important global public health issue. To our knowledge, this represents the first high-resolution mapping of anemia risk in children. In addition, these results reveal striking disparities between and within countries and highlight the influence of socio-economic and environmental factors on this condition. The findings can guide efforts to improve health systems, promote education, and implement interventions that break the cycle of poverty and anemia.