A comparison of the National Center for Health Statistics and new World Health Organization growth references for school-age children and adolescents with the use of data from 11 low-income countries

• Main Authors: Emily Rousham, Natalie Roschnik, Melba A.B. Baylon, Emily A. Bobrow, Mavzuna Burkhanova, M. Gerda Campion, Teresita Adle-Chua, Tedbabe Degefie, Caroline Hilari, Humphreys Kalengamaliro, Tamiru Kassa, Fadima Maiga, Bonifacio J. Mahumane, Mary Mukaka, Fatimata Ouattara, Amado R. Parawan, Moussa Sacko, David W. Patterson, Gaston Sobgo, Ikhtiar U. Khandaker, Andrew Hall
• Format: Article
• Language: English
• Subjects: Adolescents; Children; Developing countries; Dietetics; Medical and Health Sciences not elsewhere classified; Nutrition; Other health sciences not elsewhere classified; Statistics

BACKGROUND: In 2007 new WHO growth references for children aged 5-19 years were introduced to replace the NCHS references. OBJECTIVE: The study aimed to compare the prevalence of stunting, wasting and thinness estimated by the NCHS and WHO growth references. DESIGN: NCHS and WHO height-for-age z-scores were calculated using cross-sectional data from 20,605 schoolchildren aged 5-17 years in 11 low income countries. The differences in the percentage of stunted children were estimated for each year of age and sex. Z-scores of BMI-for-age and weight-for-height were calculated using the WHO and NCHS references respectively to compare differences in the prevalence of thinness and wasting. RESULTS: No systematic differences in mean z-scores of height-for-age were observed between the WHO and NCHS growth references. However, z-scores of height-for-age varied by sex and age, particularly during early adolescence. Among children for whom weight-for-height could be calculated, the estimated prevalence of thinness (WHO reference) was consistently higher than the prevalence of wasting (NCHS reference) by as much as 9% in girls and 18% in boys. CONCLUSION: In undernourished populations, the application of the WHO (2007) references may result in differences in the prevalence of stunting for each sex compared with using the NCHS references, as well as a higher estimated prevalence of thinness compared with wasting. An awareness of these differences is important for comparative studies or when evaluating programs. For school-age children and adolescents across all ranges of anthropometric status, the same growth references should be applied when undertaking such studies.