Describe, Locate, and Download Feasibility Files


NHANES-CMS linked data feasibility files can be used to approximate maximum sample sizes. This module provides background on the structure, location, and use of the feasibility files and demonstrates how to download the full set of variables available in the files. It will also guide you through the process of downloading and saving the feasibility files and documentation. The variables can be used to identify whether a survey participant was eligible for the CMS linkage and, if eligible, whether the participant successfully matched to CMS administrative data. The files also include variables to indicate if a survey participant has a record on each of the CMS administrative data files described in Module 4, as well as the year of benefits coverage.

Modules 6–8 explain how to convert the files to SAS datasets and produce descriptive statistics using the data. You will use a subset of the variables in these files to assess demographic characteristics (e.g., race/ethnicity and gender) by linkage eligibility and match status. Not all programs and variables referenced in this module will be used in subsequent modules.


Task 1: Describe the Feasibility Files

NHANES-CMS linked data feasibility files can be used to approximate maximum sample sizes by demographic and health status variables. This task will describe the feasibility files and explain how they can be used to approximate a sample size prior to starting your research project.

Task 2: Locate and Download Feasibility Files and Documentation

You will need to locate and download the corresponding feasibility data files and documentation from the NCHS website for the NHANES cycles that are included in your research project.

Task 3: Locate and Download NHANES Files and Documentation

The 2011-2012 NHANES files and their accompanying documentation are used for the tutorial going forward, but similar procedures apply for all cycles of the continuous NHANES.

  • Go to the National Health and Nutrition Examination Survey page on the NCHS website.
  • On the left navigation menu, expand Questionnaires, Datasets, and Related Documentation, then expand NHANES 2011-2012, and click on Demographics Data.
  • Click on DEMO G Data [XPT – 3.6 MB] and save to C:\NHANES or other designated folder.
  • Download file documentation.
Page last reviewed: March 3, 2021
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