Key Concepts About Identifying NHANES I Variable Names and File Locations

Variables are stored in different data files. Data files are organized into 20  topic areas and by whether the data were collected on the original NHANES I sample or the detailed subsample. Usually analyses will require more than one component. For instance age and sex are in the demographics component of all the data tapes, while blood pressure measurements are in the Medical Examination Ages 1-74 years component, the cholesterol measurement is in the Biochemistry, Serology, Hematology, Blood Slides, Urine Dipst.(ick) component, and questions about previous diagnoses or taking medications for hypertension are in the Medical History Questionnaire, Ages 12-74 years component. All these variables would be required in a complete analysis of cardiovascular disease.

Data for different components of the survey are released in separate data files to facilitate a more focused analytic option for researchers and faster access over the Internet. Below is a list of the basic files in NHANES I Data Files, Documentation, Codebook  1971-75, as reviewed in the Data Structure and Contents module.  The titles indicate the topic area contents. 

General survey and medical examination sample.

 

Detailed medical examination subsample.