The public-use version of the NHANES III
Linked Mortality File was subjected to data perturbation techniques to
reduce the risk of respondent re-identification while increasing the
accessibility of NCHS micro data files. Synthetic data was substituted for
the actual date and underlying cause of death data for selected decedent
records. Information regarding vital status was not perturbed. The restricted-use
version of the NHANES III Linked Mortality File is not subjected to data
perturbation techniques. NCHS has conducted a
comparative analysis of results obtained from the public-use and
restricted-use NHANES III Linked Mortality Files.