Table of Contents

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

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 0 YEARS - 15 YEARS

ECD010 - Mother's age when born

Variable Name:
ECD010
SAS Label:
Mother's age when born
English Text:
First I have some questions about {SP NAME's} birth. How old was {SP NAME's} biological mother when {s/he} was born?
English Instructions:
ENTER AGE IN YEARS
Target:
Both males and females 0 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
15 to 44 Range of Values 5273 5273
14 14 years or younger 9 5282
45 45 years or older 10 5292
7777 Refused 5 5297
9999 Don't know 66 5363
. Missing 2 5365

ECQ020 - Mother smoked when pregnant

Variable Name:
ECQ020
SAS Label:
Mother smoked when pregnant
English Text:
Did {SP NAME's} biological mother smoke at any time while she was pregnant with {him/her}?
Target:
Both males and females 0 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 671 671
2 No 4628 5299
7 Refused 2 5301
9 Don't know 62 5363
. Missing 2 5365

ECD070A - Weight at birth, pounds

Variable Name:
ECD070A
SAS Label:
Weight at birth, pounds
English Text:
How much did {SP NAME} weigh at birth?
English Instructions:
IF ANSWER GIVEN IN POUNDS ONLY, PROBE FOR OUNCES. IF ANSWER GIVEN IN EXACT POUNDS, ENTER NUMBER OF POUNDS AND 0 OUNCES. ENTER NUMBER OF POUNDS.
Target:
Both males and females 0 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
4 to 10 Range of Values 5056 5056
3 3 pounds or less 129 5185
11 11 pounds or more 23 5208
7777 Refused 0 5208
9999 Don't know 155 5363
. Missing 2 5365

ECD070B - Weight at birth, ounces

Variable Name:
ECD070B
SAS Label:
Weight at birth, ounces
English Text:
How much did {SP NAME} weigh at birth?
English Instructions:
ENTER NUMBER OF OUNCES
Target:
Both males and females 0 YEARS - 15 YEARS
Hard Edits:
0 to 15
Code or Value Value Description Count Cumulative Skip to Item
0 to 15 Range of Values 5208 5208
7777 Refused 0 5208
9999 Don't know 155 5363
. Missing 2 5365

ECQ075 - CHECK ITEM

Variable Name:
ECQ075
English Instructions:
BOX 1. CHECK ITEM: IF REFUSED (CODE 7777) OR DON'T KNOW (CODE 9999) TO ECD070A, CONTINUE; OTHERWISE, GO TO ECQ095 (BOX 2).
Target:
Both males and females 0 YEARS - 15 YEARS

ECQ080 - Weight more/less than 5.5 lbs

Variable Name:
ECQ080
SAS Label:
Weight more/less than 5.5 lbs
English Text:
Did {SP NAME} weigh . . .
Target:
Both males and females 0 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 More than 5-1/2 lbs. (2500 g), or 100 100
2 Less than 5-1/2 lbs. (2500 g)? 21 121 ECQ095
7 Refused 0 121 ECQ095
9 Don't know 34 155 ECQ095
. Missing 5210 5365

ECQ090 - Weight more/less than 9.0 lbs

Variable Name:
ECQ090
SAS Label:
Weight more/less than 9.0 lbs
English Text:
Did {SP NAME} weigh . . .
Target:
Both males and females 0 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 More than 9 lbs. (4100 g), or 9 9
2 Less than 9 lbs. (4100 g)? 85 94
7 Refused 0 94
9 Don't know 6 100
. Missing 5265 5365

ECQ095 - CHECK ITEM

Variable Name:
ECQ095
English Instructions:
BOX 2. CHECK ITEM ECQ095: IF SP AGE = 2-15 YEARS CONTINUE; OTHERWISE, GO TO END OF SECTION.
Target:
Both males and females 0 YEARS - 15 YEARS

WHQ030E - How do you consider your child's weight

Variable Name:
WHQ030E
SAS Label:
How do you consider your child's weight
English Text:
How do you consider {SP} weight?
Target:
Both males and females 2 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Overweight 532 532
2 Underweight 296 828
3 About the right weight 3549 4377
7 Refused 0 4377
9 Don't know 6 4383
. Missing 982 5365

MCQ080E - Your child was overweight

Variable Name:
MCQ080E
SAS Label:
Your child was overweight
English Text:
Has a doctor or health professional ever told you that {SP} was overweight?
Target:
Both males and females 2 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 547 547
2 No 3835 4382 End of Section
7 Refused 0 4382 End of Section
9 Don't know 1 4383 End of Section
. Missing 982 5365

ECQ150 - Help your child control weight

Variable Name:
ECQ150
SAS Label:
Help your child control weight
English Text:
Are you now doing anything to help {SP} control {his/her} weight?
Target:
Both males and females 2 YEARS - 15 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 431 431
2 No 116 547
7 Refused 0 547
9 Don't know 0 547
. Missing 4818 5365