Usagi

Usagi is a software tool created by the Observational Health Data Sciences and Informatics (OHDSI) team and is used to help in the process of mapping codes from a source system into the standard terminologies stored in the Observational Medical Outcomes Partnership (OMOP) Vocabulary (http://www.ohdsi.org/data-standardization/vocabulary-resources/).
The word Usagi is Japanese for rabbit and was named after the first mapping exercise it was used for; mapping source codes used in a Japanese dataset into OMOP Vocabulary concepts.

Mapping source codes into the OMOP Vocabulary is valuable for two main reasons:
When converting a raw dataset into the OMOP Common Data Model (CDM) (http://www.ohdsi.org/data-standardization/the-common-data-model/), translating source specific codes into standard concepts (i.e. RxNorm or SNOMED) translates the source data into a “common language” other CDMs follow.
Having source codes tied into the OMOP Vocabulary concepts allow a researcher to leverage the power of finding relevant source codes leveraging classification terminologies in the OMOP Vocabulary (e.g. find all antipsychotic medications or find all condition codes related to heart failure).