Restricted NCHS Variables

Restricted data is information that could compromise the confidentiality of survey respondents or institutions, or is sensitive by nature. To access these variables, a proposal must be approved by the Research Data Center. The following links take you to information about the specific data system. We recognize that these lists are not exhaustive, so if after reviewing this documentation you cannot find the information you are looking for, please email rdca@cdc.gov. Please refer to these lists when preparing the data dictionary for your RDC proposal.

We encourage researchers to review all of the methodological information (i.e. analytic guidelines and sample design documentation) available about the data before submitting a proposal.

• Geographic Codes for all NCHS Surveys
• National Health and Nutrition Examination Survey (NHANES)
• National Health Care Surveys
  • National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS)
  • National Hospital Discharge Survey (NHDS)
  • National Nursing Home Survey (NNHS) and National Nursing Assistant Survey (NNAS)
  • National Home and Hospice Care Survey (NHHCS) and National Home Health Aide Survey (NHHAS)
  • National Survey of Residential Care Facilities (NSRCF)
  • National Post-acute and Long-term Care Study (NPALS)
  • National Hospital Care Survey (NHCS)
• National Health Interview Survey (NHIS)
• National Survey of Family Growth (NSFG)
• NCHS Data Linkage Activities
  • Linked Mortality Data Products
  • Linked Medicare Enrollment and Claims Files Data
  • Linked Medicaid Enrollment and Claims Data
  • Linked Social Security Benefit History Data
  • Linked Housing Assistance Program Files Data
  • Linked Department of Veterans Affairs Administrative Data
• NCHS Rapid Surveys System
• National Vital Statistics System (NVSS) Data Release and Access Policy
  • Birth Data Files
    • National Maternal and Infant Health Survey
  • Mortality Data Files
    • Multiple Cause of Death Data File
    • Drug Involved Mortality Restricted Variables
    • Redacted Death Certificate Literal Text File
• Research and Development Survey (RANDS)
• State and Local Area Integrated Telephone Survey (SLAITS)
  • National Survey of Children’s Health (NSCH)
  • National Survey of Children with Special Health Care Needs (CSHCN)