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 Functioning Questionnaire (variable name prefix FNQ) section is part of the NHANES household interview and was newly added for the 2019-2020 survey cycle, replacing the Disability (DLQ) and Physical Functioning (PFQ) sections from the previous data collection cycles. In recent years, much of the science evolved regarding disability measurement, which warranted a new questionnaire section that would better capture information on functional difficulties in the U.S. population. This newly developed FNQ section included two sets of questions: 15 items collecting information for children 5 to 17 years, and 17 items focusing on adults 18 years and older. The present file (FNQC_K_R) contains functioning and disability data from children 5-17 years old. Adult FNQ data are available in a separate file, FNQA_K_R.
Questions included in the FNQ among children are based on a subset of items from the Washington Group/United Nations Children’s Fund (UNICEF) Child Functioning Module (Washington Group on Disability Statistics, 2020).
FNQ section topics include:
- Current use of corrective lenses (i.e., glasses or contact lenses) or a hearing aid, and difficulty with vision and hearing (FNQ010 - FNQ040);
- Difficulty with mobility such as walking for a short (100 m) or longer (500 m) distance, and the need to use equipment or assistance for walking (FNQ050 – FNQ090);
- Difficulty with communicating, learning, and controlling behavior (FNQ100 – FNQ130); and
- Emotional difficulties such as feeling worried, anxious, or nervous; and very sad or depressed (FNQ140– FNQ150).
All survey participants aged 5 and 17 years old in the NHANES 2019-March 2020 convenience sample were eligible.
Interview Setting and Mode of Administration
These questions were asked, in the home, by trained interviewers using the Computer-Assisted Personal Interview (CAPI) system.
An adult family member aged 18 years or older served as the proxy and provided information for child participants younger than 16 years old. Participants 16 years and older were interviewed directly.
The NHANES 2019-2020 FNQ is available 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. During the 2019-2020 data collection cycle, periodic QC checks were performed on the FNQ data being collected; and interviewer-specific feedback and retraining was performed as appropriate.
Data Processing and Editing
Questionnaire interview responses were entered into a tablet and then uploaded into a computerized database in the same manner as other sections of the Survey Participant Questionnaire. The data were then edited for completeness, consistency, and illogical values.
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.