Comparative Analysis of the Public-Use And Restricted-Use National Health Interview Survey (NHIS) Linked Mortality Files

Kimberly A. Lochner, National Center for Health Statistics (NCHS), CDC
Robert A. Hummer, University of Texas at Austin
Christine S. Cox, National Center for Health Statistics (NCHS), CDC

The National Center for Health Statistics (NCHS) updated mortality follow-up for the 1986 to 2000 NHIS cross-sectional data. These restricted-use NHIS Linked Mortality Files were made available through the NCHS Research Data Center. Recently, NCHS released a public-use version of the NHIS Linked Mortality Files that includes a limited amount of perturbed information for decedents. To demonstrate the comparability between the public-use and restricted-use versions of the linked mortality files, we estimated the relative hazard for all-cause and cause-specific mortality risk using a Cox proportional hazards model. The pooled 1986 to 2000 NHIS Linked Mortality Files contain 1,576,171 records and 120,765 deaths. The sample for the comparative analyses included 897,232 records and 114,264 deaths. The comparative analyses show that the two data files yield very similar results for both all-cause and cause-specific mortality. Our findings should provide analysts with the confidence to use the perturbed public-use NHIS linked mortality files.