Nutritional anthropometry--validity of cut-off points

The present communication seeks to describe an alternate approach of arriving at cut-off levels using ratio of percentiles for (i) differentiating normal children from the undernourished ones, and (ii) identifying the severely undernourished group of children in the community on the basis of body weight and height. It also examines validity of the cut-off levels presently used of weight for age (Gomez and Indian Academy of Paediatrics classification) and height for age parameters. 1. The cut-off levels are independent of the reference standard and, as such, the same cut-off levels could be used irrespective of the standards. 2. It is desirable to have separate cut-off levels for preschool and school age groups. The use of common cut-off points for both the age groups seems to result in loss of sensitivity of the order of over 5 per cent. 3. The use of the 90 per cent cut-off level in the Gomez classification misclassifies some of the normals as undernourished, thereby tending to overestimate the problem of undernutrition in communities. 4. The body weight groups based on the suggested cut-off points do bear a relationship to the prevalence of signs of PEM--the greater the weight deficit, the higher the prevalence of signs of PEM in preschool children.