PROGNOSTIC PERFORMANCE OF SEVERAL ANTHROPOMETRIC INDICATORS FOR PREDICTING LOW AND INSUFFICIENT BIRTH-WEIGHT

Weight gain and several anthropometric indicators were studied in a sa mple of 181 pregnant women. The period considered ranged from the 12th to the 34th weeks of gestation. Changes in all of the attributes were calculated and related to a birth weight below 3,000 g. Optimal cut-o ff points for each indicator were defined as those which minimize a lo ss function which depends on the rates of false positives and false ne gatives. The independent predictive capacity of each attribute was ass essed by means of sensitivity, specificity, positive and negative pred ictive values, relative risk, and two ''measures of detectability'' as sociated to the ROC (relative operating characteristic) curves of the attribute. A logistic regression model was fitted by searching for the best combination of indicators. The individual predictive capacities of the attributes were considerably improved when they were combined i nto a logistic equation. (C) 1995 Wiley-Liss, Inc.