• 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
  • FSQBOX5 - CHECK ITEM
  • FSQ165 - HH FS benefit: ever received
  • FSQ171 - HH FS benefit: receive in last 12 months
  • FSD230 - HH FS benefit: currently receive
  • FSD225 - HH FS benefit: time since last received
  • FSQ235 - HH FS benefit: amount received last time
  • FSQBOX7 - CHECK ITEM
  • FSQ162 - HH WIC benefit: receive in last 12 month
  • FSQBOX8 - CHECK ITEM
  • FSD650ZC - CH WIC benefit: receive in last 12 month
  • 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.
  • FSQBOX9 - CHECK ITEM
  • FSD650ZW - WM WIC benefit: receive in last 12 month
  • FSQBOX10 - CHECK ITEM
  • FSD660ZW - WM WIC benefit: currently receive
  • FSD670ZW - WM WIC benefit: # of months received
• Appendix 1
• Appendix 2

National Health and Nutrition Examination Survey

2011-2012 Data Documentation, Codebook, and Frequencies

Food Security (FSQ_G)

Data File: FSQ_G.xpt

First Published: July 2015

Last Revised: NA

Component Description

The Food Security section (variable name prefix FSQ) provides personal 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 month is also included in this section.

Individual-level food security items for adults and children were implemented in the NHANES in 2000, and added for adolescents in 2005. Starting 2011, data collection on individual-level food security items was discontinued.

2. Supplemental Nutrition Assistance Program (SNAP)/Food Stamp program benefits Food Stamp program benefits
All SNAP/Food Stamp benefits questions were collected at the household level. One adult responded to these questions for the entire household during the household interview. 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; time since last received benefits within last 12 months; and the amount of benefits the household received last time. In 2011-2012, minor modifications were made to the data collection instruments to allow the household with current SNAP/Food Stamp benefits recipient to be identified as well.

These household-level data on SNAP/Food Stamp benefits are released on all household participants’ records.

3. Women, Infants and Children (WIC) program benefits 
Data collected for WIC benefits included one household-level question as well as 7 individual-level questions for participants birth to 11 years old and 3 individual-level questions for women 12-59 years old. 

In the household interview, an adult responded to the question on whether anyone in the household received WIC benefits in the last 12 months. This household-level question is released on all household participants’ records.

For children participants’ WIC benefits, information was collected on current participation, participation in the last 12 month, and total length (in months) of benefits received. Similar to previous cycles, current participation and participation in the last 12 months were ascertained for children birth to 5 years of age. Starting in 2007-2008, the target age group for the benefit length question was extended from children birth to 5 years old to birth to 11 years old. Additional information was also obtained on WIC participation during various important periods in early childhood, including prenatal, infancy, and 1-4 years old. These data were collected through adult proxy during the household interview as part of the Dietary Behavior and Nutrition questionnaire (DBQ) and released on the individual participant’s record.

For female participants 12 to 59 years old, information was collected on current WIC participation, participation in the last 12 month, and total length (in months) of benefits received. These questions were administered as part of the Reproductive Health questionnaire (RHQ) during the interview in the MEC, using the Computer-Assisted Personal Interviewing-CAPI (interviewer administered) system. Due to disclosure risks, the WIC benefits data will only be released for women aged 20 years and above in the present dataset. Data for women 12-19 years old 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. Incoming FSQ 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 but provided no valid response to any of the questions about children’s food security were classified using the specifications for households with no child.

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

For households without children under the age of 18, their household food security category (FSDHH) should be identical to their adult food security category (FSDAD).

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 8 such records in the 2011-2012 dataset, 5 of them from households with children. These records contain missing values for FSDHH, FSDAD, and FSDCH.

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 or did not know the exact date (day, month, and year) that the household last received SNAP/Food Stamp benefits. Staring 2011, modifications were made to the skip patterns, and this question was also asked to respondent who can only recall partial information on the last benefits receiving date (day, month, or year), and those who reported a date that was more than 30-days prior to the interview day.

The household was identified as currently receiving SNAP/Food Stamp benefits (i.e., FSD230 = 1), if the reported last benefits receiving date was within 30 days prior to the interview, or if the current recipient status was confirmed by question FSQ230.

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 and released as FSD225.

When the respondent refused to answer the question or did not know the exact date, the answer to FSQ230 was used to derive the codes 55555 (current HH FS benefits recipient, last received date unknown) and 66666 (non-current HH FS benefits recipient, last received date unknown) for variable FSD225.

FSD670ZC, FSD670ZW (Number of months the participant received WIC benefit)
This information was collected using two-part (number and unit) questions to allow respondents to report the length in either month or year. The released variables were edited to standardize the reported length to number of months.

A few responses to this item appeared unlikely (e.g., a mother or a child receiving WIC for longer than WIC regulations stipulate). Some of them may have plausible explanations for longer WIC intake (such as a mother with consecutive births/pregnancies) while others may result from recall bias. Data users need to be cautious when analyzing this information.

FSD650ZW (Women received WIC benefit in last 12 month)
Similar to previous data collection cycles, this question only asked of female participants who were pregnant at the time of interview or who had given birth in the two years period prior to the interview.

FSD660ZW (Women currently received WIC benefit)
This question only asked of female participants who received WIC benefits in the last 12 months, and were pregnant or 0-12 months postpartum at the time of interview. The postpartum screening criterion for this question is a new addition started in 2007-2008. It helps to better classify eligibility for WIC benefit.

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 benefits in the FSQ section were collected as part of this family questionnaire. In 2011-2012, 41 participants had missing values to 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.”

In 2011-2014, a new sample design was implemented into the survey to include an oversample of Asian Americans. For more details on NHANES sample design and related analytic issues, please refer to the NHANES Analytic Guidelines, 2011-2012 available at: https://wwwn.cdc.gov/nchs/nhanes/analyticguidelines.aspx.

Since 2007, pregnant women and individuals 12-19 years old were no longer oversampled in the survey. Those changes have led to a reduced number of pregnant participants ages 8-19 and 45-59. WIC benefit information was collected for female participants aged 12-59 years in 2011-2012. Due to potential disclosure risks, 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: FSD650ZW, FSD660ZW, and FSD670ZW. 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_G_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 of these 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: http://www.fns.usda.gov/sites/default/files/FSGuide_0.pdf

Codebook and Frequencies