Pooled Analysis of Global, Regional and Country-Level Prevalence of Childhood Stunting, Wasting and Underweight in 62 Low- and Middle- Income Countries, 2006-2018

Abstract

Background: In 2016, undernutrition as manifested in childhood stunting, wasting and underweight were estimated to cause 1.0 million deaths, 3.9% of years of life lost, and 3.8% of disability-adjusted life years (DALYs) globally. The high disease burden due to child growth failure demands regular monitoring of its prevalence in all populations. Comparative child growth failure up-to-date information on varying geographical regions around the world is essential both to quantify population health and to prompt decision-makers to proportionately allocate interventional resources. The objective of this study is to calculate the prevalence of undernutrition, including stunting, wasting, and underweight, in low- and middle- income countries (LMICs) using the 2006-2018 demographic and health surveys (DHS), and to explore the sources of regional variations.

Method: We pooled prevalence from the DHS data in 62 (LMICs) worldwide that included children aged 0-59 months with information on stunting (n=624,734), wasting (n=625,230) and underweight (n=626,130). Anthropometric measurements (length/height and weight) were assessed by trained field-workers. Pooled prevalence of stunting, wasting and underweight were estimated by random-effects models. Sources of heterogeneity were explored through subgroup meta-analyses and meta-regression.

Findings: In these 62 LMICs, overall prevalence was 28.4% (95% CI: 26.3%, 30.7%) for stunting, 5.4% (95% CI: 4.5%, 6.6%) for wasting, and 12.3% (95% CI: 10.4%, 14.6%) for underweight. Substantial heterogeneity was evident ( I ² =99.9%; P for heterogeneity<0.0001). Subgroup and meta-regression analyses suggested that West Africa, South Asia and Southeast Asia had significantly higher estimated prevalence of all three forms of undernutrition. Estimated prevalence of stunting exceeds 40% among children in Burundi, Democratic Republic of Congo (DR Congo), Madagascar, Mozambique, Niger, Zambia, Yemen, Timor-Leste and Guatemala. Nigeria and Niger (West Africa), India (South Asia) and Timor-Leste (Southeast Asia) displayed the highest prevalence of wasting at approximately 20%. Similarly, the prevalence of underweight of 30% or above was observed in Niger, Bangladesh, India, Yemen, and Timor-Leste. Niger and Timor-Leste consistently displayed very high prevalence of all three forms of undernutrition. In multivariable meta-regression, a combination of malaria prevalence, national gross domestic product (GDP) per capita, and region (a proxy for spatial variation) explained 38%, 32%, and 45% of the variation in stunting, wasting and underweight prevalence respectively.

Interpretation: Regional, sub-regional and country disparities in undernutrition still exist. Because of the established health risks of childhood stunting, wasting and underweight, urgent global and local action and leadership are required to assist vulnerable countries to more effectively intervene to achieve the target of the second sustainable development goal — ending all forms of malnutrition by 2030.

Funding Statement: Support was provided by NIH Director’s Pioneer Award 1DP1HD086071 (SJS).

Declaration of Interests: The authors declare no competing interests.

Ethics Approval Statement: DHS protocols and guidelines were reviewed and approved by the relevant country's Ethical Review Committee and the Institutional Review Board of ICF International, USA. Written informed consent was obtained from the parents or guardians of the children before the survey. The data are entirely de-identified, aggregated and publicly available; therefore, the authors did not seek further ethical clearance.

Keywords: low-income and middle-income countries, stunting, wasting, underweight, demographic and health surveys