• Component Description
• Quality Assurance & Quality Control
• Data Processing and Editing
• Analytic Notes
• References
• Codebook
  • SEQN - Respondent sequence number
  • FSD032A - HH Worried run out of food
  • FSD032B - HH Food didn't last
  • FSD032C - HH Couldn't afford balanced meals
  • FSQBOX1 - CHECK ITEM
  • FSD041 - HH Adults cut size or skip meals
  • FSD052 - HH How often adults cut size/skip meals
  • FSD061 - HH Eat less than should
  • FSD071 - HH Hungry, but didn't eat
  • FSD081 - HH Lost weight, no money for food
  • FSQBOX2 - CHECK ITEM
  • FSD092 - HH Adults not eat whole day
  • FSD102 - HH How often adults not eat for day
  • FSQBOX3 - CHECK ITEM
  • FSD032D - HH Relied on low-cost food for child
  • FSD032E - HH Couldn't feed child balanced meal
  • FSD032F - HH Child not eating enough
  • FSQBOX4 - CHECK ITEM
  • FSD111 - HH Cut size of child meals
  • FSD122 - HH Child skip meals
  • FSD132 - HH How often child skip meals
  • FSD141 - HH Child hungry in last 12 months
  • FSD146 - HH Child not eat whole day
  • FSDHH - Household food security category
  • FSDAD - Adult food security category
  • FSDCH - Child food security category
  • FSD151 - HH Emergency food received
  • FSQ165 - HH FS benefit: ever received
  • FSD165N - HH FS benefit: # of people ever received
  • FSQ012 - HH FS benefit: receive in last 12 months
  • FSD012N - HH FS benefit: # of people received(12m)
  • FSD230 - HH FS benefit: currently receive
  • FSD230N - HH FS benefit: #people currently receive
  • FSD795 - HH FS benefit: # of months received
  • FSD225 - HH FS benefit: time since last received
  • FSD235 - HH FS benefit: amount received last time
  • FSD855 - HH FS benefit: anticipate will receive
  • FSD860 - HH FS benefit: time will receive
  • FSQ865 - HH FS benefit: amount will receive
  • FSQBOX5 - CHECK ITEM
  • FSQ162 - HH WIC benefit: receive in last 12 month
  • FSQ760 - HH WIC benefit: received in last 30 days
  • FSD760N - HH WIC benefit: no. people received
  • FSQBOX6 - CHECK ITEM
  • FSQ653 - CH WIC benefit: ever received
  • FSD660ZC - CH WIC benefit: currently receive
  • FSD675 - CH WIC benefit: received in infancy
  • FSD680 - CH WIC benefit: received b/w 1-4 yrs old
  • FSD670ZC - CH WIC benefit: # of months received
  • FSQ690 - CH WIC benefit: Mom received while preg.
  • FSQ695 - CH WIC benefit: starting month of preg.
  • FSQBOX7 - CHECK ITEM
  • FSD652ZW - WM WIC benefit: receive in latest preg.
  • FSD672ZW - WM WIC benefit: starting month of preg.
  • FSD652CW - WM WIC benefit: receive post-partum
  • FSQBOX8 - CHECK ITEM
  • FSD660ZW - WM WIC benefit: currently receive
• Appendix 1
• Appendix 2

National Health and Nutrition Examination Survey

2017-2018 Data Documentation, Codebook, and Frequencies

Food Security (FSQ_J)

Data File: FSQ_J.xpt

First Published: July 2021

Last Revised: February 2022

Component Description

The Food Security section (variable name prefix FSQ) provides individual and household-level interview data on the following topics:

1. Household food security
In the household interview, an adult responded to the U.S. Food Security Survey Module (US FSSM) questions (Bickel G, et al, 2000). There are 18 items for households with children under the age of 18 years and 10 items for households without children. Questions refer to all household members, not just NHANES participants. Three categorical household-level variables were created to characterize the overall food security status for the entire household, the adults in the household, and the children in the household. Responses to the 10 or 18 US FSSM items and the categorical data derived from these responses are released on each household participant’s record.

A question on household member’s use of emergency foods from food banks, soup kitchens, or other organizations in the last 12 months is also included in this section.

2. Supplemental Nutrition Assistance Program (SNAP)/Food Stamp program benefits
All SNAP/Food Stamp benefits questions were collected at the household level. Starting in 2015-2016, the questionnaire for SNAP/Food Stamp benefits in the household interview was redesigned to obtain a more complete picture of all benefit recipients in the household. The data collection instruments were modified to identify each household member’s SNAP/Food Stamp benefit receipt status on the household roster. The data were then summarized at the household level.

Within each household, for each family that participated in NHANES, one adult responded to questions about SNAP/Food Stamp benefits received by all household members. Information collected included whether anyone in the household had ever received SNAP/Food Stamp benefits; whether anyone in the household received benefits in the last 12 months; whether anyone in the household is a current SNAP/Food Stamp benefits recipient; and whether anyone in the household was notified they would receive benefits within the next month. For households with benefit recipients in the past 12 months, the number of months benefits were received; the time since benefits were last received; and the amount of benefits the household received last was also collected. If anyone in the household was notified that they were to receive benefits, the time until they were to receive SNAP/Food Stamp benefits and the amount they expected in benefits was also obtained.

Household-level data on SNAP/Food Stamp benefits are released on all household participants’ records. The time since benefits were last received and the time until anticipated benefits will be received was calculated for each family within the household, based on the family interview date, and released at the family level.

3. Women, Infants and Children (WIC) program benefits 
Data collected for WIC benefits included three household-level questions as well as six individual-level questions for participants aged birth to 5 years, one individual-level question for children 1-5 years, and four individual-level questions for women aged 12 years and over.

In the household interview, an adult from each family responded to the questions on whether anyone in the household received WIC benefits in the last 12 months. Beginning in 2015-2016, questions on current WIC participation in the last 30 days and the number of people in the household receiving WIC benefits were added. These household-level questions are released on all household participants’ records.

For children participants, the target age group for the WIC benefit questions was changed from 0-11 to 0-5 years, starting in the NHANES 2015-2016. Children’s WIC participation data were collected through adult proxy during the household interview as part of the Dietary Behavior and Nutrition questionnaire (DBQ). During a cognitive testing conducted in 2014, considerable recalling errors were observed among proxies for children aged 6-11 years old, which triggered this change in the target group. In addition, starting in 2015-2016, instead of whether these children received benefits in the last 12 months, information was collected on whether they ever received WIC benefits, since the latter provided a preferable time reference for children in this age group. Similarly, information on current participation, total length (in months) of benefits received, and WIC participation during various important periods in early childhood, including prenatal, infancy, and 1-4 years old, was also collected and released on the individual participant’s record.

For female participants 12 years and older, a new WIC module was added in 2015-2016 to determine WIC participation for pregnant and postpartum women separately. The new questions will allow researchers to determine whether a woman participated prenatally and/or postnatally. The new questions were adapted from the National Center for Education Statistics’ Early Childhood Longitudinal Study, Birth Cohort (ECLS-B). Women 12 years and older were asked about WIC benefits received during the latest pregnancy, the month of pregnancy when benefits started, and whether benefits were received post-partum. Like previous years, information was also collected on current WIC participation. These questions were administered as part of the Reproductive Health questionnaire (RHQ) during the Mobile Examination Center (MEC) interview, using the Computer-Assisted Personal Interview-CAPI (interviewer administered) system. Due to potential disclosure risk, the WIC benefits data will only be released for women aged 20 years and above in the public dataset. Data for all women 12 years and older will be available in the Research Data Center (RDC) only. Please refer to the Analytic Notes section for more details.

The table in Appendix 1 provides detailed information on each of the four FSQ components described above. Appendix 2 highlights the changes in the FSQ section among the latest five release cycles.

Quality Assurance & Quality Control

The automated interview systems used in NHANES are programmed with built-in consistency checks to reduce data entry errors. All the data were reviewed for accuracy and completeness. NHANES staff reviewed taped interviews, traveled to field sites to observe interviews, read interviewer comments, and attended training and re-training sessions to maintain the high-quality data.

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.

FSDHH, FSDAD, FSDCH (Household, adult, and child food security category)
Eighteen FSSM questions were asked of households with children under the age of 18. Ten questions were asked of households without children. Three categorical variables, each with four response levels, were created based on the number of affirmative responses for those questions. These categorical variables could be used to characterize the overall food security status for the entire household, the adults in the household, and the children in the household. The algorithms used to derive these categorical variables are described below:

FSDHH (Household food security category):

Count affirmative responses in these 18 items: FSD032a, FSD032b, FSD032c, FSD032d, FSD032e, FSD032f, FSD041, FSD052, FSD061, FSD071, FSD081, FSD092, FSD102, FSD111, FSD122, FSD132, FSD141, and FSD146. Derive the codes as the following:

1 = Household full food security: no affirmative response in any of these items.
2 = Household marginal food security: 1-2 affirmative responses.
3 = Household low food security: 3-5 affirmative responses for household without children under the age of 18; 3-7 affirmative responses for household with children.
4 = Household very low food security: 6-10 affirmative responses for household without children under the age of 18; 8-18 affirmative responses for household with children.

Households with children where no valid response was provided to any of the questions about children’s food security were classified using the specifications for households without children.

FSDAD (Adult food security category):

Count affirmative responses in these 10 items: FSD032a, FSD032b, FSD032c, FSD041, FSD052, FSD061, FSD071, FSD081, FSD092, and FSD102. Derive the codes as the following:

1 = Adult full food security: no affirmative response in any of these items.
2 = Adult marginal food security: 1-2 affirmative responses.
3 = Adult low food security: 3-5 affirmative responses.
4 = Adult very low food security: 6-10 affirmative responses.

FSDCH (Child food security category):

This category is only generated for households with children under the age of 18. Count affirmative responses in these 8 items: FSD032d, FSD032e, FSD032f, FSD111, FSD122, FSD132, FSD141, and FSD146. Derive the codes as the following:

1 = Child full or marginal food security: no affirmative response in any of these items.
2 = Child marginal food security: 1 affirmative response.
3 = Child low food security: 2-4 affirmative responses.
4 = Child very low food security: 5-8 affirmative responses.

Definition of FSSM affirmative response

Affirmative response for FSSM questions are defined as:

• Answered "often true" or "sometimes true" (i.e., codes 1 or 2) for items FSD032a, FSD032b, FSD032c, FSD032d, FSD032e, or FSD032f.
• Answered "yes" (i.e., code 1) for items FSD041, FSD061, FSD071, FSD081, FSD092, FSD111, FSD122, FSD141, or FSD146.
• Answered "almost every month", or "some months but not every month" (i.e., codes 1 or 2) for items FSD052, FSD102, or FSD132.

No food security categories are assigned if all or most of these items were answered as “don’t know” or “refusal.” There are 29 such records in the 2017-2018 dataset, 19 of them from households with children. These records contain missing values for FSDHH, FSDAD, and FSDCH.

FSD165-FSQ865 (all variables for SNAP/Food Stamp benefits)
Starting in 2015-2016, information on the receipt of SNAP/Food Stamp benefits by all household members was provided in the present file: ever (FSQ165); the number of people ever received (FSD165N); received in the last 12 months (FSQ012); the number of people who received in the last 12 months (FSD012N); currently receiving (FSD230); the number of people currently receiving (FSD230N); number of months received benefits (FSD795); time since last received benefits (FSD225); amount of benefits last received (FSD235); if they anticipate will receive benefits (FSD855); time until they expect to receive them (FSD860); and amount they anticipate will receive. Receipt of SNAP/Food Stamp benefits by all individuals residing in the household, both survey and non-survey participants, was included. In households with more than one family where there were inconsistencies across families, all data were reviewed and reconciled.

FSD230 (Currently receive SNAP/Food Stamp benefits)
In previous cycles, the question on whether any members of the household currently receive SNAP/Food Stamp benefits (i.e., FSQ230) was only asked when the respondent refused to answer, did not know the exact date (day, month, and year) that the household last received SNAP/Food Stamp benefits, or the date reported was more than 30-days prior to the interview day. FSD230 was then derived from reported benefit receiving date (if the reported last benefits receiving date was within 30 days prior to the interview), or the information reported in question FSQ230. Beginning in 2015-2016, in the revised module, the question (i.e., FSQ755) was directly asked to all family respondents and released in FSD230. Respondents with affirmative answers to FSQ755 were followed up with a question asking them to identify all persons living in the household who are currently receiving benefits from a household roster.

FSD225 (Time since last received SNAP/Food Stamp benefits) 
During the household interview, the respondent was asked to report the date that the household last received SNAP/Food Stamp benefits. A variable was then derived by calculating the number of days between the time the household last received the SNAP/Food Stamp benefit and the date of interview for the corresponding family. The derived variable was released as FSD225 at the family level.

FSQ235 (Amount last received SNAP/Food Stamp benefits)
Starting in 2015-2016, the amount last received in benefits was determined by asking about the date and the amount last received by all persons in the household who received SNAP/Food Stamps in the last 12 months. The latest amount received by the household was released at the household level.

FSD795 (number of months received SNAP/Food Stamp benefits)
The number of months SNAP/Food Stamp benefits were received is included for households with current recipients and those who received them in the last 12 months. When a household had both current recipients and past recipients in the last 12 months, the total number of months were calculated by checking for overlapping months. For example, if a household member is currently receiving benefits from May to July, and another household member received benefits from February to May, the total number of months was 6 (2 + 4 = 6), in the past 12 months.

FSD860 (time expected to receive SNAP/Food Stamp benefits)
Starting in 2015-2016, for any household member who anticipated receiving benefits, the date when they expected to receive the benefits was asked. The date was used to calculate the number of days between the family interview and the date they expected to receive SNAP/Food Stamp benefits.

FSD760N (number of people in the household received WIC benefits in the past 30 days)
Beginning in 2015-2016, the family respondent was asked whether anyone living in the household received WIC benefits in the past 30 days. Respondents with affirmative answers were followed up with a question (i.e., FSQ770) asking them to identify all persons living in the household who received benefits from a household roster. In addition to these household-level questions, child and female participants were also asked about whether they were receiving WIC benefits at the time of their own interviews (i.e., FSD660ZC and FSD660ZW). Responses to FSQ770, FSD660ZC, and FSD660ZW were used to derive the data in FSD760N. Receipt of WIC benefits by both survey and non-survey participants residing in the household was included. In households with more than one family where there were inconsistencies across families, all data were reviewed and reconciled.

FSD670ZC (number of months the participant received WIC benefits)
This information was collected using two-part (number and unit) questions to allow respondents to report the length in either months or years. The released variable was edited to standardize the reported length to number of months.

FSD652ZW (women received WIC benefits during latest pregnancy)
Information on WIC participation by women during their current (FSQ652a) or last (FSQ652b) pregnancy was obtained. The combined information is included in FSD652ZW.

FSD660ZW (women currently received WIC benefits)
This question was asked of female participants who were pregnant or 0-24 months postpartum at the time of interview. The postpartum screening criterion for this question was added in 2007-2008 to better classify eligibility for WIC benefits and included women 0-2 years postpartum by calculating the differences in years between the reported current age and the age of last delivery. It was then modified in 2015-2016 to include women 0-24 months postpartum by adding a question specifically asking the year and month of the last delivery and comparing those with the interview date.

Analytic Notes

NHANES has assessed household food security with the U.S. Food Security Survey Module (US FSSM) since 1999. Similar modules have been used in various surveys, including the Census Bureau's Current Population Survey (CPS) and a growing number of State, local, and regional studies, such as the California Health Interview Survey (CHIS). For more information on food security measurement, please refer to the USDA's website at: http://www.ers.usda.gov/topics/food-nutrition-assistance/food-security-in-the-us/measurement.aspx.

The NHANES household interview included two questionnaires: a sample participant questionnaire to collect information regarding each individual survey participant’s personal health status, and a family questionnaire to collect information at the family level, such as total income for the family, food availability in the family, etc. The sample participant questionnaire was answered by participants themselves (adult proxy for child under 16 years old). The family questionnaire required an adult family member, preferably the head of the family, to respond to these questions for the entire family. The information on household food security status and SNAP/Food Stamp program as well as WIC program benefits in the FSQ section were collected as part of this family questionnaire. In 2017-2018, 463 participants had missing values for all of these items in the FSQ section because the family questionnaire was not administered. Most common reasons for missing the family questionnaire interview were: “no eligible adult respondent in the family available” or “refusal.”

Due to potential disclosure risk, this file does not include data of WIC benefit related variables for females less than 20 years old. For female participants 12-19 years old, records are coded as missing for the following variables: FSD652ZW, FSD672ZW, FSD652CW, and FSD660ZW. Please note that these exclusions were not made to the FSQ data files released prior to the 2007-2008 cycle. Analysts wishing to combine data for multiple years should pay careful attention to these changes. The complete data file containing all variables for females 12 years and older (FSQ_J_R) is available through the NCHS Research Data Center.

FSQ data were collected in the household and in the MEC. For data items collected in the household interview, the interview sample weights may be used in their analysis. However, if the data analysis requires merging of data collected in the household with data collected in the MEC, examination sample weights should be used for analyses. The recommended weights for each individual component in the FSQ section are listed in the table in Appendix 1. 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. Both are available on the NHANES website.

References

• Bickel G, Nord M, Price C, Hamilton W, Cook J. Guide to Measuring Household Food Security Revised 2000. U.S. Department of Agriculture, Food and Nutrition Service, Alexandria VA. March, 2000. Available from: https://naldc.nal.usda.gov/download/38369/PDF

Codebook and Frequencies