Abstract

Background Anaemia is a major health problem worldwide. Global estimates of anaemia burden are crucial for developing appropriate interventions to meet current international targets for disease mitigation. We describe the prevalence, years lived with disability, and trends of anaemia and its underlying causes in 204 countries and territories. Methods We estimated population-level distributions of haemoglobin concentration by age and sex for each location from 1990 to 2021. We then calculated anaemia burden by severity and associated years lived with disability (YLDs). With data on prevalence of the causes of anaemia and associated cause-specific shifts in haemoglobin concentrations, we modelled the proportion of anaemia attributed to 37 underlying causes for all locations, years, and demographics in the Global Burden of Disease Study 2021. Findings In 2021, the global prevalence of anaemia across all ages was 24 center dot 3 (95 uncertainty interval UI 23 center dot 9-24 center dot 7), corresponding to 1 center dot 92 billion (1 center dot 89-1 center dot 95) prevalent cases, compared with a prevalence of 28 center dot 2% (27 center dot 8-28 center dot 5) and 1 center dot 50 billion (1 center dot 48-1 center dot 52) prevalent cases in 1990. Large variations were observed in anaemia burden by age, sex, and geography, with children younger than 5 years, women, and countries in sub-Saharan Africa and south Asia being particularly affected. Anaemia caused 52 center dot 0 million (35 center dot 1-75 center dot 1) YLDs in 2021, and the YLD rate due to anaemia declined with increasing Socio-demographic Index. The most common causes of anaemia YLDs in 2021 were dietary iron deficiency (cause-specific anaemia YLD rate per 100 000 population: 422 center dot 4 95% UI 286 center dot 1-612 center dot 9), haemoglobinopathies and haemolytic anaemias (89 center dot 0 58 center dot 2-123 center dot 7), and other neglected tropical diseases (36 center dot 3 24 center dot 4-52 center dot 8), collectively accounting for 84 center dot 7% (84 center dot 1-85 center dot 2) of anaemia YLDs. Interpretation Anaemia remains a substantial global health challenge, with persistent disparities according to age, sex, and geography. Estimates of cause-specific anaemia burden can be used to design locally relevant health interventions aimed at improving anaemia management and prevention. Funding Bill & Melinda Gates Foundation. Copyright (c) 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.