Prevalence and trends of stunting among pre-school children, 1990-2020

Abstract Objective To quantify the prevalence and trends of stunting among children using the WHO growth standards. Design Five hundred and seventy-six nationally representative surveys, including anthropometric data, were analysed. Stunting was defined as the proportion of children below −2sd from the WHO length- or height-for-age standards median. Linear mixed-effects modelling was used to estimate rates and numbers of affected children from 1990 to 2010, and projections to 2020. Setting One hundred and forty-eight developed and developing countries. Subjects Boys and girls from birth to 60 months. Results In 2010, it is estimated that 171 million children (167 million in developing countries) were stunted. Globally, childhood stunting decreased from 39·7 (95 % CI 38·1, 41·4) % in 1990 to 26·7 (95 % CI 24·8, 28·7) % in 2010. This trend is expected to reach 21·8 (95 % CI 19·8, 23·8) %, or 142 million, in 2020. While in Africa stunting has stagnated since 1990 at about 40 % and little improvement is anticipated, Asia showed a dramatic decrease from 49 % in 1990 to 28 % in 2010, nearly halving the number of stunted children from 190 million to 100 million. It is anticipated that this trend will continue and that in 2020 Asia and Africa will have similar numbers of stunted children (68 million and 64 million, respectively). Rates are much lower (14 % or 7 million in 2010) in Latin America. Conclusions Despite an overall decrease in developing countries, stunting remains a major public health problem in many of them. The data summarize progress achieved in the last two decades and help identify regions needing effective intervention

Is Malnutrition Declining? an Analysis of Changes in Levels of Childhood Malnutrition Since 1980

Nutritional status is the best global indicator of well-being in children. Although many surveys of children have been conducted since the 1970s, lack of comparability between them has made it difficult to monitor trends in child malnutrition. Cross-sectional data from 241 nationally representative surveys were analysed in a standard way to produce comparable results of low height-for-age (stunting). Multilevel modelling was applied to estimate regional and global trends from 1980 to 2005. The prevalence of stunting has fallen in developing countries from 47% in 1980 to 33% in 2000 (i.e. by 40 million), although progress has been uneven according to regions. Stunting has increased in Eastern Africa, but decreased in South-eastern Asia, South-central Asia and South America; Northern Africa and the Caribbean show modest improvement; and Western Africa and Central America present very little progress. Despite an overall decrease of stunting in developing countries, child malnutrition still remains a major public health problem in these countries. In some countries rates of stunting are rising, while in many others they remain disturbingly high. The data we have presented provide a baseline for assessing progress and help identify countries and regions in need of population wide interventions. Approaches to lower child malnutrition should be based on successful nutrition programmes and policies

Algorithms for converting estimates of child malnutrition based on the NCHS reference into estimates based on the WHO Child Growth Standards

<p>Abstract</p> <p>Background</p> <p>The child growth standards released by the World Health Organization (WHO) in 2006 have several technical advantages over the previous 1977 National Center for Health Statistics (NCHS)/WHO reference and are recommended for international comparisons and secular trend analysis of child malnutrition. To obtain comparable data over time, earlier surveys should be reanalyzed using the WHO standards; however, reanalysis is impossible for older surveys since the raw data are not available. This paper provides algorithms for converting estimates of child malnutrition based on the NCHS reference into estimates based on the WHO standards.</p> <p>Methods</p> <p>Sixty-eight surveys from the WHO Global Database on Child Growth and Malnutrition were analyzed using the WHO standards to derive estimates of underweight, stunting, wasting and overweight. The prevalences based on the NCHS reference were taken directly from the database. National/regional estimates with a minimum sample size of 400 children were used to develop the algorithms. For each indicator, a simple linear regression model was fitted, using the logit of WHO and NCHS estimates as, respectively, dependent and independent variables. The resulting algorithms were validated using a different set of surveys, on the basis of which the point estimate and 95% confidence interval (CI) of the predicted WHO prevalence were compared to the observed prevalence.</p> <p>Results</p> <p>In total, 271 data points were used to develop the algorithms. The correlation coefficients (R²) were all greater than 0.90, indicating that most of the variability of the dependent variable is explained by the fitted model. The average difference between the predicted WHO estimate and the observed value was <0.5% for stunting, wasting and overweight. For underweight, the mean difference was 0.8%. The proportion of the 95% CI of the predicted estimate containing the observed prevalence was above 90% for all four indicators. The algorithms performed equally well for surveys without the entire age coverage 0 to 60 months.</p> <p>Conclusion</p> <p>To obtain comparable data concerning child malnutrition, individual survey data should be analyzed using the WHO standards. When the raw data are not available, the algorithms presented here provide a highly accurate tool for converting existing NCHS estimates into WHO estimates.</p

Comparison of the World Health Organization (WHO) Child Growth Standards and the National Center for Health Statistics/WHO international growth reference: implications for child health programmes

Abstract Objectives To compare growth patterns and estimates of malnutrition based on the World Health Organization (WHO) Child Growth Standards (‘the WHO standards') and the National Center for Health Statistics (NCHS)/WHO international growth reference (‘the NCHS reference'), and discuss implications for child health programmes. Design Secondary analysis of longitudinal data to compare growth patterns (birth to 12 months) and data from two cross-sectional surveys to compare estimates of malnutrition among under-fives. Settings Bangladesh, Dominican Republic and a pooled sample of infants from North America and Northern Europe. Subjects Respectively 4787, 10 381 and 226 infants and children. Results Healthy breast-fed infants tracked along the WHO standard's weight-for-age mean Z-score while appearing to falter on the NCHS reference from 2 months onwards. Underweight rates increased during the first six months and thereafter decreased when based on the WHO standards. For all age groups stunting rates were higher according to the WHO standards. Wasting and severe wasting were substantially higher during the first half of infancy. Thereafter, the prevalence of severe wasting continued to be 1.5 to 2.5 times that of the NCHS reference. The increase in overweight rates based on the WHO standards varied by age group, with an overall relative increase of 34%. Conclusions The WHO standards provide a better tool to monitor the rapid and changing rate of growth in early infancy. Their adoption will have important implications for child health with respect to the assessment of lactation performance and the adequacy of infant feeding. Population estimates of malnutrition will vary by age, growth indicator and the nutritional status of index population

Supporting information for National, regional, and worldwide estimates of low birthweight rates in 2015, with trends from 2000: a systematic analysis

Data produced by the World Health Organization, UNICEF, LSHTM and Johns Hopkins University to estimate national low birthweight (LBW) and numbers for 195 countries. LBW data was collated through a systematic review of national routine/registration systems, nationally representative surveys, and other data sources, and subsequently modelled using restricted maximum likelihood estimation with country-level random effects. Data includes a list of 1447 rate data points used as an input to the modelled estimates, yearly national-level covariates for each of the 195 countries studied from 2000 to 2015, and information on estimated low birthweight rates from 2000 to 2015 for 148 countries with data. Stata code used to generate these estimates is provided

Complementary feeding in the WHO Multicentre Growth Reference Study

Aim: To describe complementary feeding practices in the Multicentre Growth Reference Study (MGRS) sample. Methods: Food frequency questionnaires and 24-h dietary recalls were administered to describe child feeding throughout the first 2 y of life. This information was used to determine complementary feeding initiation, meal frequency and use of fortified foods. Descriptions of foods consumed and dietary diversity were derived from the 24-h recalls. Compliance with the feeding recommendations of the MGRS was determined on the basis of the food frequency reports. Descriptive statistics provide a profile of the complementary feeding patterns among the compliant children. Results: Complementary feeding in the compliant group began at a mean age of 5.4 mo (range: 4.8 (Oman)-5.8 mo (Ghana)). Complementary food intake rose from 2 meals/d at 6 mo to 4-5 meals in the second year, in a reverse trend to breastfeeding frequency. Total intake from the two sources was 11 meals/d at 6-12 mo, dropping to 7 meals/d at 24 mo. Inter-site differences in total meal frequency were mainly due to variations in breastfeeding frequency. Grains were the most commonly selected food group compared with other food groups that varied more by site due to cultural factors, for example, infrequent consumption of flesh foods in India. The use of fortified foods and nutrient supplements was also influenced by site-variable practices. Dietary diversity varied minimally between compliance groups and sites. Conclusion: Complementary diets in the MGRS met global recommendations and were adequate to support physiological growth

Complementary feeding and attained linear growth among 6-23-month-old children

Abstract Objective To examine the association between complementary feeding indicators and attained linear growth at 6-23 months. Design Secondary analysis of Phase V Demographic and Health Surveys data (2003-2008). Country-specific ANOVA models were used to estimate effects of three complementary feeding indicators (minimum meal frequency, minimum dietary diversity and minimum adequate diet) on length-for-age, adjusted for covariates and interactions of interest. Setting Twenty-one countries (four Asian, twelve African, four from the Americas and one European). Subjects Sample sizes ranging from 608 to 13 676. Results Less than half the countries met minimum meal frequency and minimum dietary diversity, and only Peru had a majority of the sample receiving a minimum adequate diet. Minimum dietary diversity was the indicator most consistently associated with attained length, having significant positive effect estimates (ranging from 0·16 to 1·40 for length-for-age Z-score) in twelve out of twenty-one countries. Length-for-age declined with age in all countries, and the greatest declines in its Z-score were seen in countries (Niger, −1·9; Mali, −1·6; Democratic Republic of Congo, −1·4; Ethiopia, −1·3) where dietary diversity was persistently low or increased very little with age. Conclusions There is growing recognition that poor complementary feeding contributes to the characteristic negative growth trends observed in developing countries and therefore needs focused attention and its own tailored interventions. Dietary diversity has the potential to improve linear growth. Using four food groups to define minimum dietary diversity appears to capture enough information in a simplified, standard format for multi-country comparisons of the quality of complementary diet

Parental Height and Child Growth From Birth to 2 years in the WHO Multicentre Growth Reference Study

inear growth from birth to 2 years of children enrolled in the World Health Organization Multicentre Growth Reference Study was similar despite substantial parental height differences among the six study sites. Within-site variability in child length attributable to parental height was estimated by repeated measures analysis of variance using generalized linear models. This approach was also used to examine relationships among selected traits (e.g. breastfeeding duration and child morbidity) and linear growth between 6 and 24 months of age. Differences in intergenerational adult heights were evaluated within sites by comparing mid-parental heights (average of the mother\u27s and father\u27s heights) to the children\u27s predicted adult height. Mid-parental height consistently accounted for greater proportions of observed variability in attained child length than did either paternal or maternal height alone. The proportion of variability explained by mid-parental height ranged from 11% in Ghana to 21% in India. The average proportion of between-child variability accounted for by mid-parental height was 16% and the analogous within-child estimate was 6%. In the Norwegian and US samples, no significant differences were observed between mid-parental and children\u27s predicted adult heights. For the other sites, predicted adult heights exceeded mid-parental heights by 6.2-7.8 cm. To the extent that adult height is predicted by height at age 2 years, these results support the expectation that significant community-wide advances in stature are attainable within one generation when care and nutrition approximate international recommendations, notwithstanding adverse conditions likely experienced by the previous generation