The NHANES survey content is determined after a rigorous evaluation process including consideration of criteria such as public health importance, feasibility of the proposed survey items and burden to survey participants. This information is important as you determine the scope of your analysis and which variables to include. For example, your analysis may require background information, such as:
- Survey Contents, which shows the years components were collected and when changes to the components occurred,
- Sample Person Questionnaire, and
- MEC Components Description, which is the survey protocol for obtaining the physical examination measures in the survey.
Step 1: Find Survey Contents
From the homepage, select the link titled Questionnaires, Data Sets, and Related Documentation, then select the NHANES 2001-2002 link. Now, in the Contents at a Glance section, and click the Survey Contents link. After the PDF file of the Survey Contents opens, scroll to the third page, where the chart of when variables were collected is displayed. By reviewing this chart you can determine if the components you are interested in were collected for all the years available or only some of the years, and design your analysis accordingly.
Step 2: Find Questionnaire Questions
Select the Survey Questionnaires, Examination Components and Laboratory Components link in the Contents in Detail section. Now, select on the Blood Pressure link under the Sample Person Questionnaire heading. This link opens to the blood pressure questions asked of the survey participants and lists possible responses. Be sure to review these questions, the possible answers, and whether or not the question was part of a skip pattern.
Step 3: Find MEC Component Descriptions
Select the Examination Components link under the Examination and Laboratory heading. A PDF file of the MEC Components Description opens. Review this file for descriptions of the components offered in the MEC. Be sure to review the protocol as necessary.