Table 1.

Clinical data used for input to OMOP2OBO mapping algorithm.

OMOP domain and vocabulary	Data wavea	Concept level	Concepts	Labels	Synonyms
Condition SNOMED-CTb	Standard Concepts Used in Practice	Concept	29,129	29,129	86,630
		Ancestor	1,421,104	1,389,525	N/A
	Standard Concepts Not Used in Practice	Concept	80,590	80,590	194,264
		Ancestor	3,458,072	3,393,343	N/A
Drug Ingredient RxNormc	Standard Concepts Used in Practice	Concept	1693	1693	1865
		Ancestor	1697	1696	N/A
	Standard Concepts Not Used in Practice	Concept	10,110	10,110	11,235
		Ancestor	10,578	10,578	N/A
Measurement LOINCd	Standard Concepts Used in Practice	Concept	1606	1606	41,917
		Ancestor	20,784	21,196	N/A
	Standard Concepts Not Used in Practice	Concept	2477	2477	73,612
		Ancestor	23,457	24,306	N/A

OMOP Observational Medical Outcomes Partnership.

^aConcepts were mapped in two data waves according to whether or not they had been used at least once in clinical practice (i.e., Concepts Used in Practice) or not (i.e., Concepts Not Used in Practice).

^bThe Systematized Nomenclature of Medicine—Clinical Terms (SNOMED-CT) is the Observational Medical Outcomes Partnership (OMOP) standard vocabulary used for Condition Occurrence concepts.

^cRxNorm is the OMOP standard vocabulary used for Drug Exposure Ingredient concepts.

^dThe Logical Observation Identifiers, Names and Codes (LOINC) is the OMOP standard vocabulary used for Measurement concepts.