A new method for estimating a standardized prevalence of child malnutrition from anthropometric indicators

Abstract

Although anthropometric indicators are widely used for assessing the nutritional status of children, lack of consensus on the cut-off points for prevalence estimates has precluded the use of standard analytical methods in population surveys. A simple method for estimating a standardized prevalence of child malnutrition from anthropometric indicators is presented. The method is based on comparing the distribution of the indicator with that of the normalized NCHS reference population, the underlying assumption being that both distributions are nearly normal. Standardized prevalence is defined as the proportion of cases in the observed population that is outside the normal distribution of the reference values, which can be estimated from the mean and standard deviation of the standardized Z-scores of the population, by using a formula based on the mathematical properties of the normal probability curve. A reference table is included which provides computer-estimated prevalence rates for different mean Z-scores and standard deviations of normally distributed anthropometric indicators.