Key points
- The National Center for Health Statistics (NCHS) Data Linkage Program links National Ambulatory Medical Care Survey (NAMCS) Health Center (HC) Component data with data from other agencies.
- Linking NAMCS HC Component data with the National Death Index data 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 (NCHS) links data from the National Ambulatory Medical Care Survey (NAMCS) Health Center (HC) Component and mortality information from the National Death Index (NDI).
Linking NAMCS HC Component data with NDI mortality data enables researchers to conduct patient health outcome studies. These studies investigate the connection between health factors and death.
Restricted-use
Due to confidentiality requirements, the restricted-use linked NAMCS HC Component-NDI data are accessible only through the NCHS Research Data Center (RDC) network. Researchers must submit a research proposal to the RDC.
Data dictionaries
- Mortality variables (10/11/2024)
- Death certificate and NDI match variables (10/11/2024)
Cause of death codes
- Cause of death: underlying and multiple-cause (01/03/2018)