EAL

NGHC: Childhood Nutrition and Growth (2013)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

The purpose of this report is to provide guidance on the use of the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) growth charts. It is intended for health-care providers and others who measure and assess child growth.

Inclusion Criteria:

The participants selected to review the scientific evidence and gain opinions regarding the use of the new WHO growth charts in clinical settings in the United States were chosen because of their expertise in child growth, statistical methodology, clinical application and maternal and child health policy.
CDC, National Institutes of Health (NIH) and the American Academy of Pediatrics (AAP) each had numerous representatives, and additional experts from academia, clinical professional groups and other government agencies were invited
The criteria for selection of communities were socioeconomic status that does not constrain growth of the child
Low altitude (below 1,500m)
Low enough population mobility to allow for a two-year follow-up
At least 20% of mothers in the community willing to follow international feeding recommendations
Existence of a breastfeeding support system
Existence of a research institution capable of conducting the study.

Exclusion Criteria:

Exclusion criteria for mothers and infants included maternal smoking during pregnancy or lactation
Birth at less than 37 weeks or at least 42 weeks
Multiple birth
Substantial morbidity
Low socio-economic status
Unwillingness of the mother to follow feeding criteria
Weight-for-length measurements of more than three standard deviations from the overall study median were considered to be outliers and excluded from the final sample.

Description of Study Protocol:

Recruitment

The reference populations used to create the 2006 WHO and 2000 CDC growth curves varied from NHANES I data (1971-1974), NHANES II data (1976-1980), NHANES III data (1988-1994), to the Pediatric Nutrition Surveillance System, Missouri and Wisconsin vital statistics and National vital statistics.

Design

Consensus report and recommendations.

Statistical Analysis

To calculate percentiles and Z-scores, optimal data entry and cleaning techniques were used
For both sets of curves, the data analysis treated each data point independently, even if two data points were taken for a single child
Both the WHO and CDC used a variant of the lambda-mu-sigma statistical method to describe both percentiles and Z-scores
Three-parameter linear mathematical model was used to smooth the weight data from zero to 35 months.

Data Collection Summary:

Timing of Measurements

At the meeting, participants or experts were provided with background documents describing the development of both sets of curves
Both CDC and WHO made presentations on the methods used to create the growth curves
Meeting discussion focused on the numerous factors involved in the selection of a chart, including the assessment of child growth using references
At the time of the meeting, WHO was developing but had not released growth charts for head circumference-for-age, but the charts were not discussed
At the end of the meeting, CDC asked all participants to provide written opinions about which curves should be recommended at which ages, and for which children
The panel was not asked to arrive at a consensus.

Dependent Variables

Growth: Careful procedures for training and measurement standardization were followed and high-quality instruments were used for weight and length (or stature) measurements.

In the WHO study, anthropometrists took two measurements independently and repeated measurements that exceeded preset maximum allowable differences
In general, both WHO and CDC assessed length (measured lying down) for children age younger than 24 months and stature (measured standing up) for children age 24 to 59 months
A subset of children were measured both recumbent and standing to assess the discrepancy between the two measurements and allow for connection of the curves before and after 24 months.

Description of Actual Data Sample:

Initial N

For the CDC growth charts for children <24 months: 4,697 observations
For the WHO growth charts for children <24 months: 18,973 observations for 882 distinct children
For the CDC growth charts for children 24-59 months: 9,894 observations
For the WHO growth charts for children 24-59 months: 6,669 observations.

Attrition (final N)

As above.

Age

Younger than 24 months or between 24 and 59 months.

Ethnicity

Not reported.

Other relevant demographics

Not reported.

Anthropometrics

Not reported.

Location

Maryland.

Summary of Results:

Key Findings

CDC recommends that clinicians in the United States use the 2006 WHO international growth charts, rather than the CDC growth charts, for children age younger than 24 months
The CDC growth charts should continue to be used for the assessment of growth in persons aged two to 19 years
The recommendation to use the 2006 WHO international growth charts for children age younger than 24 months is based on several considerations, including the recognition that breastfeeding is the recommended standard for infant feeding
In the WHO charts, the healthy breastfed infant is intended to be the standard against which all other infants are compared; 100% of the reference population of infants were breastfed for 12 months and were predominantly breastfed for at least four months
When using the WHO growth charts to screen for possible abnormal or unhealthy growth, use of the 2.3rd and 97.7th percentiles (or ±2 standard deviations) are recommended, rather than the fifth and 95th percentiles
Clinicians should be aware that fewer US children will be identified as underweight using the WHO charts, slower growth among breastfed infants during ages three to 18 months is normal and gaining weight more rapidly than is indicated on the WHO charts might be an early sign of overweight.

Author Conclusion:

The clinical consequences of using the WHO standards compared with the CDC reference should be evaluated over time to identify advantages and unforeseen adverse consequences of the use of the WHO standards
Research is needed on health outcomes related to different growth patterns during infancy, particularly with regard to identifying percentiles that are indicative of health problems
Finally, research should focus on the use of BMI measurements based on length in infants and toddlers as predictors of future adverse health effects.

Funding Source:

Government:

National Center for Chronic Disease Prevention and Health Promotion

Reviewer Comments:

Quality Criteria Checklist: Review Articles
Relevance Questions
	1.	Will the answer if true, have a direct bearing on the health of patients?	Yes
	2.	Is the outcome or topic something that patients/clients/population groups would care about?	Yes
	3.	Is the problem addressed in the review one that is relevant to dietetics practice?	Yes
	4.	Will the information, if true, require a change in practice?	Yes

Validity Questions
	1.	Was the question for the review clearly focused and appropriate?	Yes
	2.	Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described?	Yes
	3.	Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased?	Yes
	4.	Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible?	Yes
	5.	Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined?	N/A
	6.	Was the outcome of interest clearly indicated? Were other potential harms and benefits considered?	Yes
	7.	Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described?	Yes
	8.	Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included?	Yes
	9.	Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed?	Yes
	10.	Was bias due to the review's funding or sponsorship unlikely?	Yes