Distributions of mortality risk attributable to low nutritional status in Niakhar, Senegal

Abstract

This study proposes a method for computing the distributions of mortality risk attributable to malnutrition among children of developing countries. Population distributions of nutritional status were adjusted with a normal curve and the relation between mortality and nutritional status was fitted with a linear logistic model after controlling for age. The attributable risk for mortality could therefore be computed at any threshold of low nutritional status. The method was applied in Niakhar, Senegal, where a comprehensive study of the relation between nutritional status and mortality was conducted in 1983-1984 on approximately 5,000 children, 6-59 mo of age. The anthropometric indicators used were Z-scores of weight-for-age, weight-for-height, height-for-age, head circumference-for-age, arm circumference-for-age, triceps skinfold-for-age, and subscapular skinfold-for-age, plus arm circumference, body mass index, and 2 composite indicators. Population attributable fraction varied according to indicators selected and ranged from 31% (head circumference) to 65% (arm circumference). The 2 composite indicators summarizing the whole nutritional status provided the same value for the population attributable fraction (59 and 60%, respectively). Classic thresholds of mild, moderate, and severe malnutrition are presented, as well as the bivariate distribution of wasting and stunting. Whatever the indicator used, mortality attributable risks appeared evenly distributed along the scale of low nutritional status. Our findings question the value of using classic thresholds of mild, moderate, and severe malnutrition (developed by clinicians for practical purposes) for nutritional epidemiology.