Using height-adjusted stunting prevalence will fail disadvantaged children worldwide – Authors' reply
Authors: S V Subramanian, Omar Karlsson, Rockli Kim
Journal: The Lancet Global Health (2022)

We thank Jef Leroy and colleagues for their reply to our Comment.1Subramanian S Karlsson O Kim R Revisiting the stunting metric for monitoring and evaluating nutrition policies.Lancet Glob Health. 2022; 10: e179-e180Summary Full Text Full Text PDF PubMed Scopus (2) Google Scholar We underscored that the prevalence of stunting is often used as a population-level measure for child undernutrition—regardless of how it ought to be used—and numerous national and global development goals are based on it. Short maternal stature is overwhelmingly the strongest determinant of stunting, and it has a far stronger association with stunting than does measures of current living standards.2Kim R Rajpal S Joe W et al.Assessing associational strength of 23 correlates of child anthropometric failure: an econometric analysis of the 2015–16 National Family Health Survey, India.Soc Sci Med. 2019; 238112374Crossref Scopus (27) Google Scholar We reasoned that if stunting prevalence among children reflects a mix of genetic heritability,3Karlsson O Domingue BW Kim R Subramanian SV Estimating heritability of height without zygosity information for twins under five years in low and middle-income countries: an application of normal finite mixture distribution models.SSM Popul Health. 2022; 17101043PubMed Google Scholar intergenerational insults, as well as current exposures to nutritional deficiencies and infections, it is useful to learn which part of the prevalence is specifically due to current deprivations. Obviously, environments correlate across generations, but adjustment for the correlation between maternal height and current household living standards does not meaningfully alter the prevalence of maternal-height-standardised stunting.4Karlsson O Kim R Bogin B Subramanian SV Maternal height-standardized prevalence of stunting in 67 low and middle-income countries.J Epidemiol. 2021; (published online July 10.)https://doi.org/10.2188/jea.JE20200537Crossref PubMed Scopus (3) Google Scholar Contrary to what Leroy and colleagues suggest, our Comment did not question that achieving child growth close to the 2006 WHO standard is desirable. Neither did we deny the importance of child stunting that is determined by short maternal height. However, health implications associated with high stunting prevalence caused by short maternal height and by current exposures to nutritional deficiencies and infections are likely to differ. Indeed, ecological correlations of crude stunting prevalence and prevalence of maternal-height-standardised stunting with other indicators of child health suggest that the latter appears to be more important.4Karlsson O Kim R Bogin B Subramanian SV Maternal height-standardized prevalence of stunting in 67 low and middle-income countries.J Epidemiol. 2021; (published online July 10.)https://doi.org/10.2188/jea.JE20200537Crossref PubMed Scopus (3) Google Scholar Leroy and colleagues needlessly extrapolate our reasoning to other child development indicators, although our Comment was specific to the metric of stunting. While more studies are needed, maternal height is unlikely to influence other child development measures to the same extent that it influences stunting. For instance, in terms of relative risk, maternal height was found to have an almost three times greater association with stunting than with mortality among children under 5 years.5Özaltin E Hill K Subramanian SV Association of maternal stature with offspring mortality, underweight, and stunting in low to middle-income countries.JAMA. 2010; 303: 1507-1516Crossref PubMed Scopus (268) Google Scholar Do Leroy and colleagues believe that children in south Asia are experiencing as many harmful exposures to nutritional deprivations and infections as children in west and central Africa, despite having less than half the under-5 mortality rate (38 deaths per 1000 vs 91 deaths per 1000)? Equating the prevalence of stunting, which is approximately 32% in both regions, with current environmental deficits would lead to anomalous conclusions, and prioritisation based on it will inevitably fail the most disadvantaged children worldwide. Indeed, The Gambia, Mali, and Senegal are the countries that experience an increase in the prevalence of stunting after standardising maternal height.5Özaltin E Hill K Subramanian SV Association of maternal stature with offspring mortality, underweight, and stunting in low to middle-income countries.JAMA. 2010; 303: 1507-1516Crossref PubMed Scopus (268) Google Scholar Therefore, is it ethical to use the crude stunting prevalence metric to guide policymakers towards the goal of removing nutritional deficiencies in children's current environment? We declare no competing interests Revisiting the stunting metric for monitoring and evaluating nutrition policiesGlobally, as well as in India, the prevalence of stunting is a commonly used metric to quantify undernutrition among children. Stunting prevalence is the proportion of children younger than 5 years who are too short for their age, according to the 2006 WHO growth standard, constructed from the Multi Growth Reference Study (MGRS).1 Using the MGRS standard, around 38% of children in India are stunted.2 This metric is also used by countries to monitor the effect of current policies that are in place to reduce the child undernutrition burden. Full-Text PDF Open AccessUsing height-adjusted stunting prevalence will fail disadvantaged children worldwideIn their Comment (February, 2022),1 S V Subramanian and colleagues challenge the validity of using the prevalence of child stunting to monitor and evaluate nutrition policies. Their argument is based on a fundamental misunderstanding of the 2006 WHO growth standards and how to appropriately use and interpret stunting. The authors espouse a dangerous and unethical position. Full-Text PDF Open Access