NCHS Data Linkage

2019 Restricted-Use Linked Mortality Files

NCHS survey data have been linked to the NDI data containing information on mortality status, date of death, and cause of death. Unlike the public-use files, the restricted-use files have information on adults and children and the data were not subjected to perturbation techniques. The restricted-use Linked Mortality Files (LMFs) have been updated with mortality follow-up data through December 31, 2019.

Descriptions of the methods used for linkage and analytic considerations for the 2019 LMF can be found in the following online report:
2019 NCHS-NDI Matching Methodology and Analytic Considerations [PDF – 421 KB]

Data Access

Due to confidentiality requirements, the restricted-use Linked Mortality Files are accessible only through the NCHS Research Data Center (RDC). All interested researchers must submit a research proposal to the RDC. Please see the RDC web site for instructions on submitting a proposal (RDC website).

To avoid risk of participant re-identification researchers are not allowed to use public-use and restricted-use Linked Mortality Files, together, in the RDC.

Restricted-Use Data Dictionaries:

 Cause of Death Codes