Effects of Error in Age on the Anthropometric Investigation of Nutritional Status of Young Children

Short Abstract: Age is an important variable in the anthropometric investigation of nutritional status of children. Bias and random error are common in children’s age data. We assess the effect of bias and random error in age on (i) estimates of malnutrition; and on (ii) the mortality discriminating power of age dependent anthropometric indicators. Accurate age, weight, height and mortality data were collected for 1,571 Bangladeshi children under five years of age. We introduce systematic bias and random error into the age variable and compute anthropometric indicators using both the correct original data and the data with errors. Results from different data sets are compared. Positive age bias over estimates while negative bias under estimates malnutrition. It is shown statistically and empirically in the paper that if malnutrition in the population is less than 50%, random error in age overestimates malnutrition; if it is more than 50%, it underestimates malnutrition; and if it is 50%, there will be no effect. Both bias and random error affect the mortality discriminating power of anthropometric indices. Errors in age data of young children deserve serious attention to make anthropometric investigation of young children meaningful and useful.