Implication of New WHO Growth Standards on Identification of Risk Factors and Estimated Prevalence of Malnutrition in Rural Malawian Infants

Abstract

BackgroundThe World Health Organization (WHO) released new Child Growth Standards in 2006 to replace the current National Center for Health Statistics (NCHS) growth reference. We assessed how switching from the NCHS to the newly released WHO Growth Standards affects the estimated prevalence of wasting, underweight and stunting, and the pattern of risk factors identified.Methodology/Principal FindingsData were drawn from a village-informant driven Demographic Surveillance System in Northern Malawi. Children (n = 1328) were visited twice at 0–4 months and 11–15 months. Data were collected on the demographic and socio-economic environment of the child, health history, maternal and child anthropometry and child feeding practices. Weight-for-length, weight-for-age and length-for-age were derived in z-scores using the two growth references. In early infancy, prevalence estimates were 2.9, 6.1, and 8.5 fold higher for stunting, underweight, and wasting respectively using the WHO standards compared to NCHS reference (p<0.001 for all). At one year, prevalence estimates for wasting and stunting did not differ significantly according to reference used, but the prevalence of underweight was half that with the NCHS reference (p<0.001). Patterns of risk factors were similar with the two growth references for all outcomes at one year although the strength of association was higher with WHO standards.Conclusions/SignificanceDifferences in prevalence estimates differed in magnitude but not direction from previous studies. The scale of these differences depends on the population's nutritional status thus it should not be assumed a priori. The increase in estimated prevalence of wasting in early infancy has implications for feeding programs targeting lactating mothers and ante-natal multiple micronutrients supplementation to tackle small birth size. Risk factors identified using WHO standards remain comparable with findings based on the NCHS reference in similar settings. Further research should aim to identify whether the young infants additionally diagnosed as malnourished by this new standard are more appropriate targets for interventions than those identified with the NCHS reference.

Worldwide implementation of the WHO Child Growth 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 .…”

Use of the World Health Organization child growth standards to assess how infant malnutrition relates to breastfeeding and mortality

“…8 Recent studies have investigated the direction and magnitude of these differences. [9][10][11][12] In children aged months, the prevalence of stunting (i.e. low height-for-age) and wasting (i.e.…”

“…low weight-for-age) was lower. 9,11,12 In the first half of infancy (i.e. the period from birth up to the end of the 6th month), the prevalence of stunting, wasting and underweight has been reported to be higher with WHO growth standards.…”

Implications of the WHO Child Growth Standards in rural Honduras

“…When using the WHO standards compared with the NCHS reference, other studies also found a higher proportion of stunted children (9,10,12) and a lower proportion of underweight children (8)(9)(10)12) . However, the proportion of wasted children, indicated by a WHZ of #22?00, showed more variable results.…”