Key Concepts About the Data Structure


The current NHANES, also known as Continuous NHANES, refers to the two-year cycles of data produced since 1999.



Each cycle is divided into five sections labeled by collection method: Demographics, Dietary, Examination, Laboratory, and Questionnaire.


Component Data Files

Within each section are many components – groups of related variables packaged in a data file. This division allows for efficiency in posting the data files to the website as soon as each component is completed and reviewed and faster download times.


In the picture below, click the years to see how, in Continuous NHANES, a cycle is related to the components and data files. (A screen-reader accessible version of this Flash animation is also available.)



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