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 Dietary 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 Dietary 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 Dietary 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 Dietary 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 Dietary 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 Dietary 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
Contact Us:
- National Center for Health Statistics
3311 Toledo Rd
Hyattsville, MD 20782 - 1 (800) 232-4636
- cdcinfo@cdc.gov