Comparison of World Health Organization child growth standards and National Centre for Health Statistics growth reference in the nutritional assessment of children from a tribal community

Abstract : Since the planning and implementation of interventions designed to improve child health and nutritional status are highly dependent on the growth standards used, it is important to understand the public health impact of using the new WHO2006 standards instead of NCHS 1977 reference curves. The present article focuses on the agreement between the NCHS and new WHO growth charts with respect to the classification of the nutritional state and to compare the proportion of severely acutely malnourished children among six months to sixty months of age from a tribal population in Tamil Nadu. Methodology involved secondary analysis of data from a cross sectional study which was originally done to estimate the prevalence of malnutrition among 6-60 months old tribal children in the Jawadhu hills, which is a part of the Eastern Ghats, in the state of Tamil Nadu. Children were classified into different classes of malnutrition using the two standards according to Z scores and agreement between the two standards in classifying nutritional status was checked by kappa statistics. The proportion of children with severe acute malnutrition (3 z score) was 14.1 when using new WHO standards while it was only 8.6 when using the NCHS standards. Despite a substantial agreement between the two standards (kappa 0.691), when using the new WHO standards, more children were classified as severely acutely malnourished as compared to NCHS standards. Switching to new WHO 2006 growth standards will have definite impact on case load of children identified as severely acutely malnourished and this has programmatic implications. Also it has implications on clinical setting and on national statistics used to measure the success of nutrition initiatives. Keyword :growth standards, severe acute malnutrition