MORTWTSA is a variable with eight columns and no implied decimals.
For sample adults aged 18 and older included in the 1997-2018 samples, MORTWTSA reports the sampling weight that adjusts for ineligible respondents in analyses of data linking NHIS participants during survey years 1997 to 2018 to the National Death Index (NDI) with mortality follow up through December 31, 2019. Because of changes in the universe of NHIS participants linked to the NDI, that is, included in the Linked Mortality File (LMF) data, this is the only sampling weight available for use in mortality analyses including participants in the 2015 and later NHIS samples.
Because adult survey participants who provided insufficient data for linking may differ from those who provided enough data for linking, ignoring the ineligible adult respondents could lead to biased mortality analysis. To correct this bias, the National Center for Health Statistics (NCHS) developed the eligibility-adjusted weights for use with variables in the 2019 LMF update. MORTWTSA is a mortality weight designed for use with sample adult variables and is available for the NHIS years 1997-2018. (A similar variable, MORTWT, is appropriate for weighting variables from the NHIS person files in conjunction with mortality variables and is available for the NHIS years 1986-2014).
When analyzing NHIS variables from the sample adult files in conjunction with any of the mortality variables, users should employ MORTWTSA rather than the sample adult weight (SAMPWEIGHT). SAMPWEIGHT is based on the Final Annual Sample Adult Weights (for survey years 1997 forward) in the original NHIS public use files.
MORTWTSA is one of a set of mortality variables released by the NCHS as part of the 2019 LMF update. The 2019 LMF includes mortality information for participants in the 1986-2018 NHIS samples with mortality follow up in the NDI through December 31, 2019. For more information on the LMF, including which variables it offers and the appropriate sampling weights to use when analyzing the mortality data, see the description tab of MORTELIG.
For a list of all mortality variables from the LMF included in the IPUMS NHIS, please refer to the MORTELIG variable description.
MORTWTSA is completely comparable over time.
For an overview of the LMF data, NHIS-NDI linkage activities, and more information about the public-use LMF offered through IPUMS NHIS, please refer to our user note on the Linked Mortality File.
- 1997-2018: Sample adults age 18+ eligible for mortality follow-up (MORTELIG).