Prevalence of wasting among under 6-month-old infants in developing countries and implications of new case definitions using WHO growth standards: a secondary data analysis

Abstract

ObjectivesTo determine wasting prevalence among infants aged under 6 months and describe the effects of new case definitions based on WHO growth standards.DesignSecondary data analysis of demographic and health survey datasets.Setting21 developing countries.Population15 534 infants under 6 months and 147 694 children aged 6 to under 60 months (median 5072 individuals/country, range 1710–45 398). Wasting was defined as weight-for-height z-score <−2, moderate wasting as −3 to <−2 z-scores, severe wasting as z-score <−3.ResultsUsing National Center for Health Statistics (NCHS) growth references, the nationwide prevalence of wasting in infant under-6-month ranges from 1.1% to 15% (median 3.7%, IQR 1.8–6.5%; ∼3 million wasted infants <6 months worldwide). Prevalence is more than doubled using WHO standards: 2.0–34% (median 15%, IQR 6.2–17%; ∼8.5 million wasted infants <6 months worldwide). Prevalence differences using WHO standards are more marked for infants under 6 months than children, with the greatest increase being for severe wasting (indicated by a regression line slope of 3.5 for infants <6 months vs 1.7 for children). Moderate infant-6-month wasting is also greater using WHO, whereas moderate child wasting is 0.9 times the NCHS prevalence.ConclusionsWhether defined by NCHS references or WHO standards, wasting among infants under 6 months is prevalent in many of the developing countries examined in this study. Use of WHO standards to define wasting results in a greater disease burden, particularly for severe wasting. Policy makers, programme managers and clinicians in child health and nutrition programmes should consider resource and risk/benefit implications of changing case definitions.

Worldwide implementation of the WHO Child Growth Standards

“…Governments set up committees (10)(11)(12) to scrutinize the new standards before deciding to adopt them and professional groups that use anthropometric indicators conducted thorough examination of the standards. Through this process concerns were raised (13)(14)(15)(16) and strengths were noted (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27) . The detailed evaluation made it possible to quantify the impact of the new standards on estimates of prevalence of malnutrition (28)(29)(30)(31)(32)(33)(34) and their implications for child health programmes .…”

Chronic Malnutrition

“…In 2010, in response to questions about infants <6 months by field-based practitioners, a report on MAMI [1] and a subsequent research paper [9] aimed to test previous assumptions and quantify the problem as an essential first step toward properly understanding this. An extrapolation of demographic and health survey data from 21 "high burden" low-and middle-income countries found an important burden of disease (Table 14.1).…”

A hospital-based study of severe acute malnutrition in infants less than six months and comparison with severe acute malnutrition in children 6–60 months

“…SAM in infants less than 6 months of age is not rare 1 . Lack of breast feeding practices has been found to be the culprit for SAM in this age group 2 .…”

“…Severe acute malnutrition (SAM) in infants less than 6 months of age is defined as weight-for-length less than -3 Z-score or presence of bilateral pitting oedema 1 . SAM in infants less than 6 months of age is not rare 1 .…”