• Component Description
• Eligible Sample
• Interview Setting and Mode of Administration
• Quality Assurance & Quality Control
• Data Processing and Editing
• Analytic Notes
• References
• Codebook
  • SEQN - Respondent sequence number
  • ECD010 - Mother's age when born
  • ECQ020 - Mother smoked when pregnant
  • ECD035 - Mother's pre-pregnancy weight, pounds
  • ECD045 - Mother's height, inches
  • ECD070A - Weight at birth, pounds
  • ECD070B - Weight at birth, ounces
  • ECQ075 - CHECK ITEM
  • ECQ080 - Weight more/less than 5.5 lbs
  • ECQ090 - Weight more/less than 9.0 lbs

National Health and Nutrition Examination Survey

2019-March 2020 Data Documentation, Codebook, and Frequencies

Early Childhood - B24 Project (EC24_K_R)

RDC Only Data File: EC24_K_R.xpt

First Published: December 2021

Last Revised: NA

Due to disclosure issues, this dataset is not available publicly. Access may be obtained through the NCHS Research Data Center (https://www.cdc.gov/rdc).

Component Description

The NHANES program suspended field operations in March 2020 due to the coronavirus disease 2019 (COVID-19) pandemic. As a result, data collection for the NHANES 2019-2020 cycle was not completed. Data collected in 2019-March 2020 can be accessed as convenience samples through the NCHS Research Data Center (RDC). Any analyses based solely on the 2019-March 2020 data would not be generalizable to the U.S. civilian non-institutionalized population. Please refer to the Analytic Notes section for more details on the use of the data.

The Early Childhood questionnaire (variable name prefix ECQ) provides information on the child participant’s birth weight as well as information on the biological mother of the child, such as the age when the child participant was born, and smoking habits of the mother while she was pregnant with the participant. In 2019, maternal pre-pregnancy height and weight questions were added for calculating pre-pregnancy BMI of the mothers of the child participants. These questions were added under the recommendation of the federal consortium coordinated by the U.S. Department of Health and Human Services’ (DHHS) Office of Disease Prevention and Health Promotion (ODPHP) and the U.S. Department of Agriculture’s (USDA) Center for Nutrition Policy and Promotion (CNPP) to support the Agricultural Act of 2014. The Act mandates that beginning with the 2020-2025 edition, the Dietary Guidelines for Americans includes comprehensive dietary recommendations for children 0-24 months. Nationally representative data on children 0-24 months, including prenatal information, are crucial to advancing the science base used to inform current and future federal nutrition and related health programs, policies, and consumer information. These newly implemented questions in NHANES were designed to fill the information gaps in this important topic. These questions have been cognitively tested by NCHS’ Collaborating Center for Question Design and Evaluation Research (CCQDER; Creamer et al., 2018).

Eligible Sample

All participants aged birth to 23 months old in the NHANES 2019-March 2020 convenience sample were eligible.

Interview Setting and Mode of Administration

These questions were asked in the home to an adult proxy, by trained interviewers, using the Computer Assisted Personal Interview (CAPI) system.

Quality Assurance & Quality Control

The CAPI system is programmed with built-in consistency checks to reduce data entry errors. CAPI also uses online help screens to assist interviewers in defining key terms used in the questionnaire. All data was reviewed by the NHANES field office staff for accuracy and completeness.

Data Processing and Editing

Frequency counts were checked, "skip" patterns were verified, and the reasonableness of question responses was reviewed. Edits were made to some variables to ensure the completeness, consistency, and analytic usefulness of the data. Edits were also made, when necessary, to address data disclosure concerns. When a variable was modified globally, as part of the editing process, the third letter in the variable name was changed from a Q (i.e., ECQ) to a D (i.e., ECD). For example, some data were collected using two variables (a number variable and a unit of measure variable) but combined into a single variable for data release purposes.

For ECD010 (age of biological mother when the sample participant was born), any reported values under 14 years were coded as 14 years and younger and any reported values over 45 years were coded as 45 years and older. This was done to protect the confidentiality of participants.

For ECD070A (weight at birth, pounds) and ECD070B (weight at birth, ounces), all responses of 3 pounds or under were collapsed into a single category with ECD070A coded as “3” and ECD070B coded as “0.” Similarly, for ECD070A and ECD070B all responses of 11 pounds or over were collapsed into a single category, with ECD070A coded as “11” and ECD070B coded as “0.” This was done to protect the confidentiality of survey participants.

Analytic Notes

The COVID-19 pandemic required suspension of NHANES 2019-2020 field operations in March 2020 after data were collected in 18 of the 30 survey locations in the 2019-2020 sample. Data collection was cancelled for the remaining 12 locations. Calculation of survey weights for this partial cycle is not possible due to incomplete data collection. Therefore, data from survey components that were only collected in 2019-March 2020 are made available as convenience samples through NCHS's Research Data Center (RDC) because unbiased estimates for the NHANES target population cannot be produced with these samples.

For survey components conducted in both 2017-2018 and 2019-2020 cycles, data collected from 2019 to March 2020 were combined with data from 2017 to 2018 to form a nationally representative sample of NHANES 2017-March 2020 pre-pandemic data. Please see the NHANES 2017-March 2020 pre-pandemic data page for detailed information on this combined sample.

References

• Creamer, L., Vickers, B., Schoua-Glusberg, A., and Glusberg, D.,2018, Evaluation of Food for Babies and Mothers’ Health Questions on the National Health and Nutrition Examination Survey B24 Month Questionnaire, Hyattsville, MD: National Center for Health Statistics. Download Report: https://wwwn.cdc.gov/QBank/Report.aspx?1199

Codebook and Frequencies