WHO standards predict death in malnourished children more accurately than other measurements
A study comparing measurements used to assess malnutrition in young children in Niger has found that the new World Health Organisation (WHO) Child Growth Standards—introduced in 2006—are accurate predictors of death of these children following their admissions for malnutrition. The study, published this week in the open access journal PLoS Medicine, compared the new WHO standards with those of the US National Center for Health Statistics (NCHS), which have long been used as an international reference. Malnutrition and hunger are some of the gravest threats to global public health, and there are an estimated 178 million malnourished children around the world. Decisions about the measurements used to diagnose malnutrition are important because they have a major impact on the cost of international food programs and the number of children that can be included. The US NCHS introduced child growth charts in 1977, based on the growth of US children, and these were adopted shortly afterwards by the WHO for international use. But in 2006 the WHO developed new Child Growth Standards, which were based on children from a variety of countries and backgrounds raised in optimal environments for healthy growth. The new WHO measures aim to provide a single international standard that represents the best description of physiological growth for all children from birth to fiv e years of age, irrespective of country.
While it is known that the WHO standards result in greater number of children estimated to be malnourished than the NCHS reference, little is known about how they predict mortality risk for malnourished children. In the study published in PLoS Medicine, Nathanael Lapidus of Epicentre, a non-profit research organisation based in Paris, and colleagues used data from a Médecins Sans Frontières nutritional program to establish how the standards differ in predicting which children's lives are at risk from malnutrition.
The researchers examined data from over 60,000 children aged between six months and five years old in Maradi, Niger—a region facing considerable climate and demographic challenges, including recurrent drought, food insecurity and one of the highest child mortality rates in the world. These were children who had already been assessed as being acutely malnourished and were receiving treatment. The researchers evaluated three measures to see which was the most accurate at predicting which children would die under treatment: the children's weight-for-height as measured by the NCHS growth chart; the children's weight-for-height measured by the WHO chart; and low mid-upper arm circumference (MUAC), which is a useful measure of malnourishment in crisis situations or when there is little training or equipment available. Of these measurements, the researcher found the WHO standards to be the m ost accurate in predicting which children died under treatment. The results were similar irrespective of children grouped by age or sex.
Some limits of the study are noted by the authors. As it was already established that the children in the study were malnourished, the researchers cannot say definitely that the WHO measure is better for predicting which children in the general population are suffering from malnourishment. The findings also do not provide guidance on the cut off points that should be used to decide whether to enter a child into a feeding program or not. But despite these difficulties, the study suggests that the new WHO growth standards present a great opportunity to advance the management of acute malnutrition, a major global public health problem.