Measuring malnutrition -The role of Z scores and the composite index of anthropometric failure (CIAF)

Background : The current WHO recommendation is to use the Z-Score or SD system to grade undernutrition which allows us to measure all the three indices and express the results in terms of Z scores or standard deviation units from the median of the international reference population. Objectives : To estimate the prevalence of undernutrition among under-five children in Coimbatore slums, using the Z-Score system of classification and the recently constructed Composite Index of Anthropometric Failure (CIAF). 2. To compare the Z-Score system with the Indian Academy of Pediatrics (IAP) classification of undernutrition. Methods : Nutritional assessment was done using anthropometry and clinical examination. Children were weighed and measured as per the WHO guidelines on Anthropometry. Epi-Info 2002 software package was used to calculate the Z scores and for statistical analysis. Results : Only 31.4% of the children studied were normal; 68.6% were in a state of "Anthropometric Failure". As per the Z score system, 49.6% were underweight (21.7% severely); 48.4% were stunted (20.3% severely) and 20.2% were wasted (6.9% severely). Whereas, as per IAP criteria, 51.4% were undernourished and 3.2% were severely undernourished. Using Underweight (low weight-for-age) as the only criterion for identifying undernourished children (as done in the Integrated Child Development Services currently) may underestimate the true prevalence of undernutrition, by as much as 21.9%. Conclusions : More widespread use of the Z-Score system is recommended for identifying all the facets of undernutrition. Estimates of the true prevalence of undernutrition must incorporate a composite index of anthropometric failure