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Mercedes De Onis - One of the best experts on this subject based on the ideXlab platform.
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algorithms for converting estimates of Child malnutrition based on the nchs reference into estimates based on the who Child Growth standards
BMC Pediatrics, 2008Co-Authors: Hong Yang, Mercedes De OnisAbstract:Background 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.
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development of a who Growth reference for school aged Children and adolescents
Bulletin of The World Health Organization, 2007Co-Authors: Mercedes De Onis, Elaine Borghi, Adelheid W Onyango, Amani Siyam, Chizuru Nishida, Jonathan SiekmannAbstract:Objective To construct Growth curves for school-aged Children and adolescents that accord with the WHO Child Growth Standards for preschool Children and the body mass index (BMI) cut-offs for adults. Methods Data from the 1977 National Center for Health Statistics (NCHS)/WHO Growth reference (1–24 years) were merged with data from the under-fives Growth standards’ cross-sectional sample (18–71 months) to smooth the transition between the two samples. State-of-the-art statistical methods used to construct the WHO Child Growth Standards (0–5 years), i.e. the Box-Cox power exponential (BCPE) method with appropriate diagnostic tools for the selection of best models, were applied to this combined sample. Findings The merged data sets resulted in a smooth transition at 5 years for height-for-age, weight-for-age and BMI-for-age. For BMI-for-age across all centiles the magnitude of the difference between the two curves at age 5 years is mostly 0.0 kg/m² to 0.1 kg/m². At 19 years, the new BMI values at +1 standard deviation (SD) are 25.4 kg/m² for boys and 25.0 kg/m² for girls. These values are equivalent to the overweight cut-off for adults (> 25.0 kg/m²). Similarly, the +2 SD value (29.7 kg/m² for both sexes) compares closely with the cut-off for obesity (> 30.0 kg/m²). Conclusion The new curves are closely aligned with the WHO Child Growth Standards at 5 years, and the recommended adult cut-offs for overweight and obesity at 19 years. They fill the gap in Growth curves and provide an appropriate reference for the 5 to 19 years age group. Bulletin of the World Health Organization 2007;85:660–667.
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who Child Growth standards based on length height weight and age
Acta Paediatrica, 2007Co-Authors: Mercedes De OnisAbstract:Aim: To describe the methods used to construct the WHO Child Growth Standards based on length/height, weight and age, and to present resulting Growth charts. Methods: The WHO Child Growth Standards were derived from an international sample of healthy breastfed infants and young Children raised in environments that do not constrain Growth. Rigorous methods of data collection and standardized procedures across study sites yielded very high-quality data. The generation of the standards followed methodical, state-of-the-art statistical methodologies. The Box-Cox power exponential (BCPE) method, with curve smoothing by cubic splines, was used to construct the curves. The BCPE accommodates various kinds of distributions, from normal to skewed or kurtotic, as necessary. A set of diagnostic tools was used to detect possible biases in estimated percentiles or z-score curves. Results: There was wide variability in the degrees of freedom required for the cubic splines to achieve the best model. Except for length/height-for-age, which followed a normal distribution, all other standards needed to model skewness but not kurtosis. Length-for-age and height-for-age standards were constructed by fitting a unique model that reflected the 0.7-cm average difference between these two measurements. The concordance between smoothed percentile curves and empirical percentiles was excellent and free of bias. Percentiles and z-score curves for boys and girls aged 0–60 mo were generated for weight-for-age, length/height-for-age, weight-for-length/height (45 to 110 cm and 65 to 120 cm, respectively) and body mass index-for-age. Conclusion: The WHO Child Growth Standards depict normal Growth under optimal environmental conditions and can be used to assess Children everywhere, regardless of ethnicity, socio-economic status and type of feeding.
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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
Public Health Nutrition, 2006Co-Authors: Mercedes De Onis, Elaine Borghi, Cutberto Garza, Adelheid W Onyango, Hong YangAbstract: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 populations.
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the world health organization global database on Child Growth and malnutrition methodology and applications
International Journal of Epidemiology, 2003Co-Authors: Mercedes De Onis, Monika BlossnerAbstract:Background: For decades nutritional surveys have been conducted using various definitions indicators and reference populations to classify Child malnutrition. The World Health Organization (WHO) Global Database on Child Growth and Malnutrition was initiated in 1986 with the objective to collect standardize and disseminate Child anthropometric data using a standard format. Methods: The database includes population-based surveys that fulfil a set of criteria. Data are checked for validity and consistency and raw data sets are analysed following a standard procedure to obtain comparable results. Prevalences of wasting stunting under- and overweight in preschool Children are presented using z-scores based on the National Center for Health Statistics (NCHS)/WHO international reference population. New surveys are included on a continuous basis and updates are published bimonthly on the database’s web site. Results: To date the database contains Child anthropometric information derived from 846 surveys. With 412 national surveys from 138 countries and 434 sub-national surveys from 155 countries the database covers 99% and 64% of the under 5 year olds in developing and developed countries respectively. This wealth of information enables international comparison of nutritional data helps identifying populations in need evaluating nutritional and other public health interventions monitoring trends in Child Growth and raising political awareness of nutritional problems. Conclusions: The 15 years experience of the database can be regarded as a success story of international collaboration in standardizing Child Growth data. We recommend this model for monitoring other nutritional health conditions that as yet lack comparable data. (authors)
Himanshu Kumar - One of the best experts on this subject based on the ideXlab platform.
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neonatal antibiotic exposure impairs Child Growth during the first six years of life by perturbing intestinal microbial colonization
Nature Communications, 2021Co-Authors: Atara Uzanyulzari, Olli Turta, Anna Belogolovski, Oren Ziv, Christina Kunz, Sarah Perschbacher, Hadar Neuman, Edoardo Pasolli, Hila Benamram, Himanshu KumarAbstract:Exposure to antibiotics in the first days of life is thought to affect various physiological aspects of neonatal development. Here, we investigate the long-term impact of antibiotic treatment in the neonatal period and early Childhood on Child Growth in an unselected birth cohort of 12,422 Children born at full term. We find significant attenuation of weight and height gain during the first 6 years of life after neonatal antibiotic exposure in boys, but not in girls, after adjusting for potential confounders. In contrast, antibiotic use after the neonatal period but during the first 6 years of life is associated with significantly higher body mass index throughout the study period in both boys and girls. Neonatal antibiotic exposure is associated with significant differences in the gut microbiome, particularly in decreased abundance and diversity of fecal Bifidobacteria until 2 years of age. Finally, we demonstrate that fecal microbiota transplant from antibiotic-exposed Children to germ-free male, but not female, mice results in significant Growth impairment. Thus, we conclude that neonatal antibiotic exposure is associated with a long-term gut microbiome perturbation and may result in reduced Growth in boys during the first six years of life while antibiotic use later in Childhood is associated with increased body mass index. In this study, Omry Koren, Samuli Rautava and colleagues report a sex-specific association between neonatal antibiotic exposure and weight and height gain during the first six years of life and showing that boys but not girls exposed to neonatal antibiotics exhibit impaired weight and height development.
Hong Yang - One of the best experts on this subject based on the ideXlab platform.
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algorithms for converting estimates of Child malnutrition based on the nchs reference into estimates based on the who Child Growth standards
BMC Pediatrics, 2008Co-Authors: Hong Yang, Mercedes De OnisAbstract:Background 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.
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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
Public Health Nutrition, 2006Co-Authors: Mercedes De Onis, Elaine Borghi, Cutberto Garza, Adelheid W Onyango, Hong YangAbstract: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 populations.
Adelheid W Onyango - One of the best experts on this subject based on the ideXlab platform.
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development of a who Growth reference for school aged Children and adolescents
Bulletin of The World Health Organization, 2007Co-Authors: Mercedes De Onis, Elaine Borghi, Adelheid W Onyango, Amani Siyam, Chizuru Nishida, Jonathan SiekmannAbstract:Objective To construct Growth curves for school-aged Children and adolescents that accord with the WHO Child Growth Standards for preschool Children and the body mass index (BMI) cut-offs for adults. Methods Data from the 1977 National Center for Health Statistics (NCHS)/WHO Growth reference (1–24 years) were merged with data from the under-fives Growth standards’ cross-sectional sample (18–71 months) to smooth the transition between the two samples. State-of-the-art statistical methods used to construct the WHO Child Growth Standards (0–5 years), i.e. the Box-Cox power exponential (BCPE) method with appropriate diagnostic tools for the selection of best models, were applied to this combined sample. Findings The merged data sets resulted in a smooth transition at 5 years for height-for-age, weight-for-age and BMI-for-age. For BMI-for-age across all centiles the magnitude of the difference between the two curves at age 5 years is mostly 0.0 kg/m² to 0.1 kg/m². At 19 years, the new BMI values at +1 standard deviation (SD) are 25.4 kg/m² for boys and 25.0 kg/m² for girls. These values are equivalent to the overweight cut-off for adults (> 25.0 kg/m²). Similarly, the +2 SD value (29.7 kg/m² for both sexes) compares closely with the cut-off for obesity (> 30.0 kg/m²). Conclusion The new curves are closely aligned with the WHO Child Growth Standards at 5 years, and the recommended adult cut-offs for overweight and obesity at 19 years. They fill the gap in Growth curves and provide an appropriate reference for the 5 to 19 years age group. Bulletin of the World Health Organization 2007;85:660–667.
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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
Public Health Nutrition, 2006Co-Authors: Mercedes De Onis, Elaine Borghi, Cutberto Garza, Adelheid W Onyango, Hong YangAbstract: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 populations.
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construction of the world health organization Child Growth standards selection of methods for attained Growth curves
Statistics in Medicine, 2006Co-Authors: Elaine Borghi, M De Onis, Cutberto Garza, J Van Den Broeck, Edward A Frongillo, Laurence M Grummerstrawn, S Van Buuren, L Molinari, Reynaldo Martorell, Adelheid W OnyangoAbstract:The World Health Organization (WHO), in collaboration with a number of research institutions worldwide, is developing new Child Growth standards. As part of a broad consultative process for selecting the best statistical methods, WHO convened a group of statisticians and Child Growth experts to review available methods, develop a strategy for assessing their strengths and weaknesses, and discuss methodological issues likely to be faced in the process of constructing the new Growth curves. To select the method(s) to be used, the group proposed a two-stage decision-making process. First, to select a few relevant methods based on a list of set criteria and, second, to compare the methods using available tests or other established procedures. The group reviewed 30 methods for attained Growth curves. Using the pre-defined criteria, a few were selected combining five distributions and two smoothing techniques. Because the number of selected methods was considered too large to be fully tested, a preliminary study was recommended to evaluate goodness of fit of the five distributions. Methods based on distributions with poor performance will be eliminated and the remaining methods fully tested and compared. Copyright © 2005 John Wiley & Sons, Ltd.
Wafaie W Fawzi - One of the best experts on this subject based on the ideXlab platform.
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effects of prenatal and postnatal maternal multiple micronutrient supplementation on Child Growth and morbidity in tanzania a double blind randomized controlled trial
International Journal of Epidemiology, 2021Co-Authors: Dongqing Wang, Uma Chandra Mouli Natchu, Anne Marie Darling, Ramadhani Noor, Ellen Hertzmark, Willy Urassa, Wafaie W FawziAbstract:BACKGROUND Maternal micronutrient status is critical for Child Growth and nutrition. It is unclear whether maternal multiple micronutrient supplementation (MMS) during pregnancy and lactation improves Child Growth and prevents Child morbidity. METHODS This study aimed to determine the effects of prenatal and postnatal maternal MMS on Child Growth and morbidity. In this double-blind, randomized-controlled trial, 8428 HIV-negative pregnant women were enrolled from Dar es Salaam, Tanzania, between 2001 and 2004. From pregnancy (12-27 weeks of gestation) through to 6 weeks postpartum, participants were randomized to receive daily oral MMS or placebo. All women received daily iron and folic acid during pregnancy. From 6 weeks postpartum through to 18 months postpartum, 3100 women were re-randomized to MMS or placebo. Child-Growth measures, haemoglobin concentrations and infectious morbidities were assessed longitudinally from birth to ≤18 months. RESULTS Prenatal MMS led to modest increases in weight-for-age z-scores (mean difference: 0.050; 95% confidence interval: 0.002, 0.099; p = 0.04) and length-for-age z-score (mean difference: 0.062; 95% confidence interval: 0.013, 0.111; p = 0.01) during the first 6 months of life but not thereafter. Prenatal or postnatal MMS did not have benefits for other Child outcomes. CONCLUSIONS Whereas maternal MMS is a proven strategy to prevent adverse birth outcomes, other approaches may also need to be considered to curb the high burdens of Child morbidity and Growth faltering.
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maternal dietary diversity and Growth of Children under 24 months of age in rural dodoma tanzania
Food and Nutrition Bulletin, 2018Co-Authors: Megan J Huang, Christopher R Sudfeld, Abbas Ismail, Said Vuai, Julius Edward Ntwenya, Mary Mwanyikasando, Wafaie W FawziAbstract:Objective:To identify predictors of maternal dietary diversity in rural Dodoma, Tanzania and assess its association with Child Growth outcomes.Methods:A cross-sectional survey of 361 mothers with c...
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human immunodeficiency virus infection diarrheal disease and sociodemographic predictors of Child Growth
Acta Paediatrica, 2007Co-Authors: Eduardo Villamor, Maulidi Fataki, Ronald J Bosch, Roger Mbise, Wafaie W FawziAbstract:Aim: To compare Growth patterns between human immunodeficiency virus (HIV)-infected and -uninfected preschool Children. To examine the associations between diarrheal and respiratory infections sociodemographic factors and Growth. Methods: A longitudinal study was conducted among 524 Children who were 6-60 mo of age at recruitment. Information on sociodemographic characteristics was collected at baseline from the caregiver. Hemoglobin malaria infection and HIV status of the Children were assessed from a blood sample. Monthly height (length if <24 mo) and weight measurements were obtained and clinical assessments carried out during an average 12 mo follow-up period. Yearly increments in height and weight were compared by HIV status incidence of diarrhea and respiratory infections and levels of sociodemographic variables. Results: After adjusting for maternal education anemia and vitamin A supplementation HIV infection was related to 2.8 cm [95% confidence interval (95% CI) 0.6 5.0] and 1.3 kg (95% CI 0.0 2.5) lower yearly length and weight gains respectively in Children who were between 6 and 11 mo old at baseline. Among Children who were 12-23 mo old at recruitment HIV infection was associated with 0.6 kg (95% CI 0.1 1.0) less yearly weight gain. HIV infection was not related to linear or ponderal Growth in Children =24 mo old. Maternal illiteracy severe Child anemia and episodes of acute diarrhea were additional risk factors for Growth delay in length. Conclusion: HIV infection is associated with linear and ponderal Growth retardation in Children aged <24 mo. Additional predictors of linear Growth retardation include preventable conditions such as poor maternal education Child anemia and diarrheal disease. (authors)
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vitamin a supplements ameliorate the adverse effect of hiv 1 malaria and diarrheal infections on Child Growth
Pediatrics, 2002Co-Authors: Eduardo Villamor, Maulidi Fataki, Roger Mbise, Ellen Hertzmark, Karen E Peterson, Donna Spiegelman, Godwin Ndossi, Wafaie W FawziAbstract:Objective. Evidence from animal experiments and observational studies in humans suggests that vitamin A plays a fundamental role in physical Growth. However, results from vitamin A supplementation trials in Children are inconsistent; whereas some did not find an overall effect on Growth, others found benefits only among specific groups, including Children with low concentrations of serum retinol or short duration of breastfeeding. The apparent lack of an overall effect of vitamin A on Growth could be attributed to context-specific distribution of conditions that affect both Growth and the response to supplementation, eg, baseline vitamin A status, deficiency of other nutrients (fat, zinc), and the presence of infectious diseases. Human immunodeficiency virus (HIV) infection, malaria, and diarrheal disease adversely affect Growth and are associated with increased prevalence of vitamin A deficiency. We hypothesize that vitamin A supplementation could ameliorate the adverse effect of these infections on Child Growth. Methods. We conducted a randomized, clinical trial among 687 Tanzanian Children who were 6 to 60 months of age and admitted to the hospital with pneumonia. Children were assigned to oral doses of 200 000 IU vitamin A (half that dose if Results. A total of 554 Children had at least 2 follow-up measurements of height or weight and constituted the study base. Baseline characteristics did not differ significantly by treatment arm. Seventy-three percent of the Children were Plasmodium falciparum ) and HIV infection were found in 24% and 9% of the Children, respectively. Median duration of follow-up was 351 days, with 10 measurements/Child, on average, irrespectively of treatment assignment. Supplementation with vitamin A among Children who had HIV infection and were Conclusions. Vitamin A supplementation improves linear and ponderal Growth in infants who are infected with HIV and malaria, respectively, and decreases the risk of stunting associated with persistent diarrhea. Supplementation could constitute a low-cost, effective intervention to decrease the burden of Growth retardation in settings where infectious diseases are highly prevalent.