Determinants of variability among nations in child growth

Abstract

This cross-national study aimed at understanding variability in growth among nations and its determinants. It examined the variability of growth among nations, the factors most important for explaining this variability, how these factors jointly determine growth, and the consistency of the patterns and relationships. A conceptual model was adapted from U. Jonsson. National data on height and weight of children, sex, ethnicity, and 15 social, economic, health, education, and political factors were combined from three secondary sources. A sequence of multiple linear regression models was used with three age groups: 1-2, 3-5, and 6-10 years. Substantial variability in growth among nations was seen in comparison to that within nations. Regression models with sex, ethnicity, food security, maternal and child care, and health services and environment explained a large percentage of this variability. Institutions, politics/ideology, economic structure, and potential resources contributed little additionally to the models. Ethnic differences among nations were observed and persisted even when models controlled for other factors, but should not necessarily be interpreted as genetic differences. Determinants for height, weight, and weight adjusted for height were somewhat different. Adjustment for only previous growth and sex explained about 90% of variability in growth, supporting the assumption that growth patterns are generally established early in life. As policy decisions and programmes addressing mild-to-moderate malnutrition are increasingly considered, the implications of cross-national variability in growth may assume greater importance. Future work should examine simultaneously the effects of national, community, family, and individual characteristics on growth using data from individuals in a number of nations.