The early childhood questionnaire (variable name prefix ECQ) includes 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. These questions were asked in the National Youth Fitness Survey (NYFS) and in the second year of the 2011-2012 National Health and Nutritional Examination Survey (NHANES).
All survey participants were eligible. Proxy respondents answered the questions for participants aged 3 to 15 years.
Interview Setting and Mode of Administration
These questions were asked, in the home, by trained interviewers using the Computer-Assisted Personal Interviewing (CAPI) system.
For details on the administration of the combined NYFS and NHANES Early Childhood (C_ECQ) section, please refer to Interviewer Procedures Manual and the Early Childhood Sample Person Participant Questionnaire on the NHANES website
Data Processing and Editing
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 Interviewer Procedures Manual.
For ECD070A (weight at birth, pounds) and ECD070B (weight at birth, ounces), all responses of 13 pounds or over were collapsed into a single category, with ECD070A coded as “13” and ECD070B coded as “0.” This was done to protect the confidentiality of survey participants.
The analysis of combined NYFS and NHANES early childhood questionnaire data must be conducted using the appropriate survey design variables, sample weights, and the basic demographic variables. Although this data was collected as the part of the household questionnaire, if it is merged with the exam data, exam sample weights should be used for the analyses.
Please refer to the Analytic Guidelines https://www.cdc.gov/nchs/nnyfs/index.htm
for further details on the use of sample weights and other analytic issues.