Summary

i2b2 uses user-controlled vocabularies to compose complex queries running on the clinical data. Such a vocabulary could be refered to as a concept scheme consisting of concepts. Concepts have at least a natural language label and some code that unambiguously identifies it. This code is also used in an association to the medical facts. So, queries of concepts relate to the clinical data. The universe of all vocabularies used in an i2b2 project is called i2b2 ontology.

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