Evaluation of the feasibility of international growth standards for school-aged children and adolescents.

Development of an international growth standard for the screening, surveillance, and monitoring of school-aged children and adolescents has been motivated by two contemporaneous events: the global surge in childhood obesity and the release of a new international growth standard for infants and preschool children by the World Health Organization (WHO). If a prescriptive approach analogous to that taken by WHO for younger children is to be adopted for school-aged children and adolescents, several issues would have to be addressed regarding the universality of growth potential across populations and how to define optimal growth in children and adolescents. A working group concluded that subpopulations exhibit similar patterns of growth when exposed to similar external conditioners of growth. However, on the basis of available data, it cannot be ruled out that some of the observed differences in linear growth across ethnic groups reflect true differences in genetic potential rather than environmental influences. Therefore, the sampling frame for the development of an international growth standard for children and adolescents would have to include multiethnic sampling strategies designed to capture the variation in human growth patterns. A single international growth standard for school-aged children and adolescents could be developed with careful consideration of the population and individual selection criteria, study design, sample size, measurements, and statistical modeling of primary growth and secondary ancillary data. The working group agreed that existing growth references for school-aged children and adolescents have shortcomings, particularly for assessing obesity, and that appropriate growth standards for these age groups should be developed for clinical and public health applications.