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
- Marko Kerac1,
- Hannah Blencowe2,
- Carlos Grijalva-Eternod1,
- Marie McGrath3,
- Jeremy Shoham3,
- Tim J Cole4,
- Andrew Seal1
- 1Centre for International Health and Development, UCL Institute of Child Health, London, UK
- 2London School of Hygiene and Tropical Medicine, London, UK
- 3Emergency Nutrition Network, Oxford, UK
- 4MRC Centre of Epidemiology for Child Health, UCL Institute of Child Health, London, UK
- Correspondence to Dr Marko Kerac, UCL Institute of Child Health,30 Guilford Street, London WC1N 1EH, UK;
Contributors MK, MM and AS conceptualised the study. MK drafted the initial manuscript. HB and MK performed the main data analysis. CGE, JS, TJC and AS contributed further analyses. All authors contributed to the development of the final manuscript.
- Accepted 29 November 2010
- Published Online First 2 February 2011
Objectives To determine wasting prevalence among infants aged under 6 months and describe the effects of new case definitions based on WHO growth standards.
Design Secondary data analysis of demographic and health survey datasets.
Setting 21 developing countries.
Population 15 534 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.
Results Using 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.
Conclusions Whether 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.
Funding This paper was written as part of the MAMI (Management of Acute Malnutrition in Infants) project, funded by the UNICEF led Inter Agency Standing Committee Nutrition Cluster (www.humanitarianreform.org/humanitarianreform/Default.aspx?tabid=74). MK, CG, MM and AS were all part-funded by MAMI. TJC was funded by the Medical Research Council (grant number G0700961).
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.
This paper is freely available online under the BMJ Journals unlocked scheme, see http://adc.bmj.com/info/unlocked.dtl