Component Description
The Diet Behavior and Nutrition (variable name prefix DBQ) section provides
personal interview data on various dietary behavior and nutrition related
topics. Many of the questions were included in NHANES II (1976-80), Hispanic
HANES (1982-84), NHANES III (1988-94), and NHANES 1999-2006. Topics included in
the section are:
- Breastfeeding and other childhood feeding practices (<=
6 yr)
- Current milk consumption pattern and types of milk (>=
1 yr)
- Milk consumption pattern throughout the life span (>= 20 yr)
- Community or government meal program participation (>= 60 yr)
- School meal program participation (4-19 yr)
- Self-appraised healthfulness level of one’s own diet (>=
16 yr)
- Frequency of getting meals prepared away from home (>= 1 yr)
- Frequency of meals got from fast-food or pizza places (>= 1 yr)
- Use of convenience foods (>= 1 yr)
- Self-perceived vegetarian (>= 1 yr)
- Food allergy (>=
1 yr)
- Meal planner/shopper/preparer status (>= 16 yr)
In 2007, a Flexible Consumer Behavior Survey (FCBS) module was added to the
NHANES. This module was developed in collaboration with the Economic Research
Service (ERS) of the U.S. Department of Agriculture (USDA). It is designed to
collect information on people’s knowledge, attitudes, and beliefs toward
nutrition and food choices. The FCBS module has two elements: a core set of
questions asked in the household interview, and a supplementary module asked in
a follow-up interview with focuses specifically designed for each 2-year data
collection cycle.
The core set of the FCBS module collects information on individual
participant’s food choices, such as getting meals prepared away from home, meals
got from fast-food or pizza places, use of convenience foods or ready-to-eat
meals bought in stores, and participant’s self-perceived vegetarian status, food
allergy, and meal planner/shopper/preparer status at home. These data are
included as part of the present DBQ section.
The core set of the FCBS module also includes questions at participant’s
family level. For example, family member’s use of special diet, availability of
certain type of foods in the family, food expenditures, as well as time spent on
food shopping and cooking dinner, and meals eaten together in the family. These
family level questions, in the core set of the FCBS module, are included in the
Consumer Behavior (CBQ) section and released in a separate file at:
https://wwwn.cdc.gov/nchs/nhanes/2007-2008/cbq_e.htm
Data from the phone follow-up FCBS supplementary module will also be released
in separate files and made available on the NHANES website. Similar to other
datasets in the NHANES 2007-2008 release cycle, all FCBS related data files can
be linked by the respondent sequence number (SEQN). For more information on the
other FCBS related data, refer to the documentations accompanying the
datasets.
Eligible Sample
The target age groups for questions in this section vary by the topic. For
example, the questions pertaining to infant nutrition and breast-feeding were
asked of proxy respondents for children 6 years of age and younger; and senior
meal program participation questions were asked of respondents 60 years of age
and older. Please review the questionnaire and codebook carefully. Frequency
counts were verified during the preparation of the file.
Interview Setting and Mode
of Administration
Questions on the frequencies of getting meals prepared away from home
(DBD895), meals got from fast-food or pizza places (DBD900), and use of
convenience foods (DBD905 and DBD910) was asked during the physical examination,
at the mobile examination center (MEC), of participants 12-15 years old. Theses
12-15 years old participants answered these questions for themselves.
The same question was asked, before the physical examination, in the home, of
participants 1-11 years and of participants 16 years and older. All other
questions in this section were asked before the physical examination, in the
home, as well.
In the home, questions were asked by trained interviews using the
Computer-Assisted Personal Interviewing (CAPI) system. Hand cards showing
response categories were also used for some questions. When necessary, the
interviewers read the hand cards to respondents. Persons 16 years of age and
older and emancipated minors were interviewed directly. A proxy provided
information for survey participants who were under 16 years of age and for
individuals who could not answer the questions themselves.
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. All of the data was reviewed by
the NHANES field office staff for accuracy and completeness.
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. When a variable was modified globally, as part of the editing process,
the third letter in the variable name was changed from a Q (i.e. DBQ) to a D
(i.e. DBD). For example, some data were collected using two variables (a number
variable and a unit of measure variable), but combined into a single variable
for data release purposes.
DBD020, DBD030, DBD040, DBD050, DBD060, and DBD080 (Breastfeeding and
other childhood feeding practices)
This information was collected using
two-part (number and unit) questions to allow respondents to report the age of
interest in days, weeks, months, or years. The released variables were edited to
standardize the reported age to number of days, using the following conversion
factors: 7 days/week, 30.4 days/month and 365 days/year.
DBD895 (Frequency of getting meals prepared away from home)
Respondents were asked how many times they had gotten meals that were prepared
away from home in the past 7 days. If the frequency was reported as "never," the
value was re-coded as zero. If the frequency was reported more than 21 times per
week, the value was re-coded as “5555.”
DBD905 and DBD910 (Use of convenience foods)
This information was collected using two-part (number and unit) questions to
allow respondents to report the frequency of interest as either per day, per
week, or per month. The released variables were edited to standardize the
reported frequency to number of times in the last 30 days. If the frequency was
reported as "never," the value was re-coded as zero.
Analytic Notes
DBD895 (Frequency of getting meals prepared away from home)
A
similar question was included in the NHANES 2005-2006 release (variable name:
DBD091). The current version was updated based on experiences from 2005-2006
data collection and results from a cognitive testing in 2006. The updates
include: 1) time frame of the question was modified from “on average, how many
meals per week…” to a more specific term “during the past 7 days”; 2) the
phrase “meals not prepared at a home” was revised as “meals prepared away
from home” to avoid negative tense; 3) the probe for different eating
establishments was shortened to reduce respondent burden and to make it easier
to understan; 4) the response “less than weekly” for 2005-06 question
DBD091 is no longer applicable.
Since the question DBD895 was asked as part of household interview for
participants 1-11 (proxy interview used) and 16 or more years of age, the
interview sample weights may be used in their analysis. However, if the data is
joined with other data from the Mobile Examination Center (MEC), the MEC sample
weights should be used. Analysis of the question, DBD895, for 12 to 15 year olds
should use the MEC sample weights because the question was asked in the MEC for
this age group.
DBD900, DBD905, and DBD910 (Frequency of meals got from fast-food or
pizza places, and use of convenience foods)
Similar to the abovementioned question DBD895, these questions were also
asked in the MEC for 12 to 15 year olds, therefore, the MEC sample weights
should be used for analysis with this age group. For analysis on participants
1-11 (proxy interview used) and 16 or more years of age, the interview sample
weights may be used if no other data from the MEC was used in the analysis.
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