Can I combine IHIS data with other NHIS variables needed for my research?
Interested users can combine variables from IHIS and NHIS public use files. Variables from the original NHIS public use files (that are not yet in the IHIS system) can be linked to an IHIS data extract. IHIS has created linking keys from the series of original NHIS variables that are used to uniquely identify households (NHISHID) or persons (NHISPID). More information, including an overview of NHIS unique identifiers, IHIS linking keys, and general guidance on how to link variables from NHIS public use files to an IHIS data extract, can be found in a user note on linking. In addition to the general guidance offered by this user note, sample Stata and SAS programs are provided to facilitate the linking process.