What is the difference between Ethnicity and Nationality?
According to the Oxford Dictionary - Ethnicity is the fact of belonging to a particular nation or people that share a cultural tradition. And nationality is a group of people with the same language, culture and history who form part of a political nation. These terms could be used as synonyms (depending on the context). Also, it should be mentioned that term nationality has a political shade of meaning. E.g., Italian is nationality and Caucasian is ethnicity.
In OMOP CDM, there are two main domains to describe people’s groups. The first one - Ethnicity contains only two concepts 38003564 Not Hispanic or Latino and 38003563Hispanic or Latino which are given in Race and ethnicity in the United States Census. We would recommend you to use Rase domain because it is wider and can be useful for the specification. https://athena.ohdsi.org/search-terms/terms?domain=Race&standardConcept=Standard&page=1&pageSize=15&query=
What use case do you have?