[Evaluation of the use of the 10th percentile of weight for age as a cut point for detection of children under nutritional risk] / Avaliação do uso do percentil 10 de peso para idade como ponto de corte para detecção de crianças sob risco nutricional.

OBJECTIVE: To evaluate the use of the 10th percentile of weight for age as a cut off point for detection of children under nutritional risk, especially for programs of alimentary supplementation. METHODS: 841 children with age between 10 days and 60 months were studied in a primary health care center located in the periphery of Ribeirão Preto, SP, Brazil. It was a cross-sectional study that included age, sex, weight and height, later computing the z scores of weight for age, height for age and weight for height, on the basis of the data of the NCHS. Through 2x2 type tables, where the results in relation with the 10th percentile (above or below this cut off point) and other indices were compared (above or below - 2 z scores), the capacity of 10th percentile of weight for age to detect children with various anthropometric deficits was estimated. RESULTS: The false negative results were always very low, between 0 and 1%, in opposition to the false positive results, that varied from 76.3 to 90.5%. The values of sensitivity/specificity have been 100/85.9%; 93.3/83.8%; 82.9/85.7%, respectively for deficits of weight for age, weight for height and height for age. CONCLUSIONS: The 10th percentile of weight for age was found adequate for population screening of children with weight for the age and weight for the height deficits (high sensitivity), but these children must be better evaluated later on (too many false positive results). For height for age deficits, the 10th percentile resulted inadequate.

Comparison of four anthropometric methods of nutritional assessment and evaluation of the agreement between two reference populations.

A total of 841 children, aged 10 days to 5 years, seen at a primary health care centre in Ribeirão Preto, Brazil, were studied in order to compare the methods of Gomez, Waterlow, Shakir, and Kanawati and McLaren and to determine the correlation between the Brazilian and the National Center for Health Statistics (NCHS) reference populations, which are frequently used in Brazil. Anthropometric measurements (weight, height, arm circumference, and head circumference) were made and personal data were obtained in order to evaluate nutritional status according to the above methods. The two reference populations were compared by the method of Gomez. The NCHS and the Brazilian reference populations were concordant. Comparison of the methods of Gomez and Shakir showed a very mild agreement in the evaluation of nutritional status. Comparison of Waterlow 'wasting' with Kanawati & McLaren and with Gomez showed a mild agreement.