Comparison of Child Undernutrition Anthropometric Indicators Across 56 Low- and Middle-Income Countries.

Importance: The United Nations' Sustainable Development Goal Target 2.2 seeks to end all forms of malnutrition by 2030 by meeting targets, including the elimination of stunting and wasting in all children younger than 5 years. Such indicators are used to monitor childhood undernutrition but may not provide a complete picture at a population level. Objective: To compare global estimates of the prevalence of undernutrition using conventional indicators of anthropometric failure (AF; stunting, underweight, and wasting); the Composite Index of Anthropometric Failure (CIAF); and a proposed classification system called Categories of Anthropometric Failure (CAF) as well as to investigate the association of the conventional indicators, CIAF, and CAF with diarrheal disease as an assessment of the validity of each measure. Design, Setting, and Participants: Cross-sectional study of the prevalence of undernutrition among children in 56 low- and middle-income countries using data from the nationally representative Demographic and Health Surveys. The study included 530 906 children younger than 5 years. Data were collected from June 2005 to December 2018 and analyzed from September 27, 2020, to February 4, 2021. Main Outcomes and Measures: Undernutrition identified according to conventional indicators (stunting, underweight, and wasting), the CIAF, and the proposed CAF classification system was estimated and compared. Six logistic regression models were used to examine the association between different classifications of anthropometric failure (AF) and morbidity. Results: A total of 530 906 children (mean [SD] age, 29.0 [17.2] months; 272 355 [51.3%] boys and 258 551 [48.7%] girls) from 56 low- and middle-income countries were included in the analysis. Estimates of undernutrition generated using the conventional indicators of stunting, underweight, and wasting were lower than estimates generated using the CIAF in all countries. The CAF classification system pointed to considerable variation across countries in children with multiple AFs, which does not correspond to the overall prevalence of undernutrition. For example, 7.5% of children in Niger and 7.1% of children in Timor-Leste were stunted, underweight, and wasted, while 56.0% of children in Niger and 71.1% of children in Timor-Leste were undernourished according to the CIAF. In addition, children who had stunting, underweight, and wasting had 1.52 (95% CI, 1.45-1.61) times the odds of diarrhea compared with children who exhibited no AFs. Conclusions and Relevance: The results of this study highlight the importance of using different approaches to aid understanding of the entire spectrum of AF with regard to research and development of policies and programs to address AF. The use of the CIAF and the CAF classification system may be useful for treatment to prevent AFs and could accelerate progress in meeting targets for the Sustainable Development Goal.