• Component Description
• Eligible Sample
• Interview Setting and Mode of Administration
• Quality Assurance & Quality Control
• Data Processing and Editing
• Analytic Notes
• Codebook
  • SEQN - Respondent sequence number
  • ECD010 - Mother's age when born
  • ECQ020 - Mother smoked when pregnant
  • 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
  • ECQ095 - CHECK ITEM
  • WHQ030E - How do you consider your child's weight
  • MCQ080E - Your child was overweight
  • ECQ150 - Help your child control weight

National Health and Nutrition Examination Survey

2017-March 2020 Data Documentation, Codebook, and Frequencies

Early Childhood (P_ECQ)

Data File: P_ECQ.xpt

First Published: July 2021

Last Revised: NA

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 and the collected data are not nationally representative. Therefore, data collected from 2019 to March 2020 were combined with data from the NHANES 2017-2018 cycle to form a nationally representative sample of NHANES 2017-March 2020 pre-pandemic data. These data are available to the public. Please refer to the Analytic Notes section for more details on the use of the data.

The Early Childhood questionnaire (variable name prefix ECQ) section of the Sample Person Questionnaire provides personal interview data for children, including the age of the biological mother when the child participant was born, smoking habits of the mother while she was pregnant with the participant, birth weight and the proxy’s assessment of the participant’s current weight.

Eligible Sample

Participants aged birth to 15 years in the NHANES 2017-March 2020 pre-pandemic sample were eligible. However, the ages of participation for some questions in this section vary. Please review the codebook carefully. Frequency counts were verified during the preparation of the file.

Interview Setting and Mode of Administration

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

For details on the administration of the P_ECQ, please refer to the NHANES 2017-2018 and 2019-2020 Interviewer Procedures Manuals and the NHANES 2017-2018 and 2019-2020 Early Childhood Sample Person Participant Questionnaires on the NHANES website.

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.

For details on the quality control/quality assurance process for this component, please refer to the NHANES 2017-2018 and 2019-2020 Interviewer Procedures Manuals on the NHANES website.

Data Processing and Editing

Frequency counts were verified during the preparation of the file.

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. Because the collected data from 18 locations were not nationally representative, these data were combined with data from the previous cycle (2017-2018) to create a 2017-March 2020 pre-pandemic data file. The examination sample weights in the demographic file should be used to calculate estimates from the combined cycles. These sample weights are not appropriate for independent analyses of the 2019-2020 data and will not yield nationally representative results for either the 2017-2018 data alone or the 2019-March 2020 data alone.

Although data in this file were collected as part of the household questionnaire, if they are merged with the MEC exam data, exam sample weights should be used for the analyses.

Please refer to the NHANES website for additional information for the NHANES 2017-March 2020 pre-pandemic data, and for the previous 2017-2018 public use data file with specific weights for that 2-year cycle.

Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.

Codebook and Frequencies