Locate Variables

Purpose

Dietary variables, and information about the variables, are stored in different data and documentation files. You will use these files to identify dietary recall variables of interest and their file locations, identify food frequency variables and their file locations, identify dietary supplement variables and their file locations, and identify correct sample weights and their file locations.  Reviewing the data file documents also is an essential part of learning about dietary variables.  

Task 1: Identify Dietary Recall Variables and Their File Locations

Dietary recall variables and information about the variables are stored within the Examination data files.  To identify dietary recall variable names and file locations, and to understand their naming conventions, you will need to consult the dietary interview files on the 2003-2004 Examination Files page.

• Key Concepts about Identifying Dietary Recall Variables and File Locations
• How to Identify Dietary Recall Variables and File Locations

Task 2: Identify Food Frequency Variables and Their File Locations

Food frequency variables and information about the variables are stored within the Questionnaire data files.  To identify food frequency variable names and file locations, and to understand their naming conventions, you will need to consult the files on the 2003-2004 Questionnaire Files page.

• Key Concepts about Identifying Food Frequency Variables and File Locations
• How to Identify Food Frequency Variables and File Locations

Task 3: Identify Dietary Supplement Variables and Their File Locations

Dietary supplement variables and information about the variables are stored within the Questionnaire data files.  To identify dietary supplement variable names and file locations, and to understand their naming conventions, you will need to consult the files on the 2003-2004 Questionnaire Files page.

• Key Concepts about Identifying Dietary Supplement Variables and File Locations
• How to Identify Dietary Supplement Variables and File Locations

Task 4: Identify Correct Sample Weights and Their File Locations

Sample weights are constructed for each 2-year survey cycle to account for over-sampling, survey non-response, and post-stratification. Because not all persons completed all portions of the survey, each individual in NHANES may be assigned multiple weight variables (see the Survey Orientation course for more information on how different sample weights are created).  It is important to select the correct weight variable for your particular analysis and take extra care to include it in your analytic dataset.

• Key Concepts about Identifying Correct Sampling Weights and File Locations
• How to Identify Correct Sampling Weights and File Locations

NHANES Dietary Tutorial Home

Dietary Data Survey Orientation

Preparing a Dietary Analytic Dataset

Basic Dietary Analyses

Advanced Dietary Analyses

Additional Resources

National Center for Health Statistics
3311 Toledo Road
Hyattsville, MD 20782
Phone: 1-866-441-NCHS (6247)
For data inquiries, use
nchsquery@cdc.gov

Problems or comments about the Tutorial?
Email the Tutorial Team: NHANESWebTutorial@cdc.gov

Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30333, U.S.A
Tel: (404) 639-3311 / Public Inquiries: (404) 639-3534 / (800) 311-3435