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 that can be used by researchers 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 of this service have access to data sets, documentation, and questionnaires from NCHS survey and data collection systems. Additional documentation can be downloaded directly from the respective survey or data collection system website.
• Data Access Tools
  The NCHS website hosts a number of useful data access tools that can be used to view interactive data and tables, perform database queries, and manipulate complex data sets.
• Data Linkage
  The NCHS Data Linkage Program is a great resource for researchers wishing to examine the factors that influence disability, chronic disease, health care utilization, morbidity, and mortality. NCHS has developed a record linkage program designed to maximize the scientific value of the Center's population-based surveys. NCHS is currently linking various NCHS surveys with air monitoring data from the Environmental Protection Agency; with death certificate records from the National Death Index; with Medicare enrollment and claims data from the Centers for Medicare & Medicaid Services; and with 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 central computerized index of death record information on file in the state vital statistics offices. Working with these state offices, NCHS established the NDI as a resource to aid epidemiologists and other health and medical investigators with their mortality ascertainment activities. The NDI is available to investigators solely for statistical purposes in medical and health research. A national file of identifying death record information (beginning with 1979 deaths) has been compiled from computer files submitted by state vital statistics offices. 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 (HHS) 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 confidentiality 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 provides a framework for RDC to identify a potential disclosure risk. 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 modes of access.