Task 1: Introduction: Sources and Structure of Linked Datasets

Data Linkage Overview

NCHS has developed a record linkage program designed to maximize the scientific value of the Center's population-based surveys. The linked data files enable you to examine factors that influence disability, chronic disease, health care utilization, morbidity, and mortality.  Respondents are considered linkage eligible for linkage to CMS administrative records if they have sufficient personal identifier information (PII) and/or did not refuse to provide their Social Security Number (SSN) or Medicare Health Insurance Claim (HIC) numbers at the interview and have a verified SSN from the Social Security Administration (SSA).

This tutorial’s focus is on the linkage of National Health and Nutrition Examination Survey (NHANES) data with enrollment and claims data from CMS.  At times you may be interested in adding information from the other linked NHANES datasets at NCHS, including the linked mortality files.  For confidentiality reasons, the linked data files mentioned in this tutorial are restricted and need to be accessed through the NCHS Research Data Center (RDC). In order to access the data, you must submit a proposal to the RDC that fully describes the data needed for an analysis.  NCHS has provided a Feasibility Study Data File that includes a limited set of variables for you to use in determining the feasibility and samples sizes of your proposed research project(s).  Links to the feasibility files webpages and the RDC website are located in the Resources section of this module.


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