Restricted-Use Linked NHCS-NDI Data

Through its data linkage program, NCHS has been able to expand the analytic utility of the data collected from National Hospital Care Survey (NHCS) by augmenting it with mortality data from the National Death Index (NDI). Linkage of NHCS data with the NDI mortality data provides the opportunity to conduct a vast array of outcome studies designed to investigate the association of a wide variety of health factors with mortality.

Descriptions of the methods used for linkage and analytic considerations for the NHCS linkages to the NDI can be found in the following online reports:

• 2014 NHCS – 2014-2015 NDI: Matching Methodology and Analytic Considerations [PDF – 397 KB]

• 2016 NHCS – 2016-2017 NDI: Matching Methodology and Analytic Considerations [PDF – 424 KB]

Data Access

Due to confidentiality requirements, the Restricted-use linked NHCS-NDI data are accessible only through the NCHS Research Data Center (RDC) Network. All interested researchers must submit a research proposal to the RDC.  Please see the RDC website for instructions on submitting a proposal.

Data Dictionary

• Mortality Variables [PDF – 259 KB]
• Death Certificate and NDI Match Variables [PDF – 233 KB]

Cause of Death Codes

• Cause of Death: Underlying and Multiple-Cause [PDF – 1.9 MB]

Additional Resources

• National Death Index (NDI)