Resources for Researchers

The National Center for Health Statistics (NCHS) is a rich source of data for researchers, teachers, and students who want to perform data analysis. This page compiles key sources of information found on the NCHS website for those who are interested in analysis of NCHS data as well as documentation and methodology of NCHS data systems.

Accessing Data for Research

• Public-use Data Files and Documentation
  Free, downloadable public-use data files are accessible from our FTP server. Users have access to data sets, documentation, and questionnaires from NCHS survey and data-collection systems. More documents can be downloaded directly from the particular survey or data-collection system website.
• Data Linkage
  The NCHS Data Linkage Program is a great resource for researchers who want to examine the factors that influence disability, chronic disease, health care utilization, morbidity, and mortality. NCHS is currently linking various NCHS surveys with air-monitoring data from the Environmental Protection Agency; death certificate records from the National Death Index; Medicare enrollment and claims data from the Centers for Medicare & Medicaid Services; and retirement, survivor, and disability insurance and supplemental security income benefit data from the Social Security Administration.
• National Death Index
  The National Death Index (NDI) is a computerized national database of death record information. Using records submitted by state vital statistics offices, NCHS established NDI as a resource to aid epidemiologists and other health and medical investigators with their mortality-related research. NDI is available to investigators solely for statistical purposes in medical and health research. Death records are added to the NDI file annually, approximately 12 months after the end of each calendar year.
• Research Data Center
  The Research Data Center (RDC) provides secure access to Department of Health and Human Services  data for researchers comfortable using SAS or a similar statistical package to analyze standard data sets. In the past, users have included epidemiologists, economists, demographers, and health scientists. RDC is responsible for protecting the privacy of the survey respondents, study subjects, and institutions from which data are collected. Consequently, all researchers must submit a research proposal outlining their need for more sensitive data. The proposal helps RDC to identify potential risks of disclosure. Once the proposal is approved, RDC works with researchers to create a data file specific to the research questions. RDC cannot send the data set but offers several options for accessing the file.