Key points
- The National Center for Health Statistics Data Linkage Program links National Hospital Care Survey (NHCS) survey data with data from other agencies.
- Linking NHCS data with the National Death Index enables researchers to conduct studies to advance public health.
- Find a list of data dictionaries, cause of death codes, and resources for restricted-use data.
Overview
The National Center for Health Statistics Data Linkage Program connects survey data with data from other agencies. This program includes data from the National Hospital Care Survey (NHCS).
The National Hospital Care Survey links NHCS data with the National Death Index (NDI) mortality (death) data to expand opportunities for further study. Such studies investigate the association of health factors with death.
Restricted-use
Restricted-use linked NHCS-NDI data can be accessed only through the National Center for Health Statistics Research Data Center (RDC) network for approved research projects.
Data dictionaries
2019 NHCS-2019–2020 NDI and 2020 NHCS-2020–2021 NDI
- Mortality variables (07/11/2025)
- Death certificate and NDI match variables (07/11/2025)
2014 NHCS-2014–2015 NDI and 2016 NHCS-2016–2017 NDI
- Mortality variables (12/18/2020)
- Death certificate and NDI match variables (12/18/2020)
Cause of death codes
- Cause of death: underlying and multiple-cause (01/03/2018)
Linkage methods and analytical support
2019 NHCS-2019–2020 NDI and 2020 NHCS-2020–2021 NDI
- Matching Methodology and Analytic Considerations (07/11/2025)
2016 NHCS-2016–2017 NDI
- Matching Methodology and Analytic Considerations (01/26/2022)
2014 NHCS-2014–2015 NDI
- Matching Methodology and Analytic Considerations (08/06/2019)