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Non Standard concept mapping(NDC) in drug_concept table


I’m trying to map my medication dataset to OMOP drug_concept table as per V6 specifications. When I read through the drug_concept_id field, it has a link of accepted concepts which filters out all the vocabs that are not standard. So, NDC which seems to be non standard filters out as well… about 8.5% of my dataset is NDC type.

  • What are the repercussions of loading a non-standard concept_id into drug_concept_id field ?

  • OR do I just input drug_concept_id = 0 for NDC rows since only standard values are accepted and then may be set drug_source_concept_id = 45018605 for example for dicyclomine ?


You have to map the non-standard concepts (NDC) to the standard ones (RxNorm), using the tables provided in the Standardized Vocabularies provided by Athena. The Book of OHDSI explains it all.

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To narrow your reading see section 6.3 Step 2: Create the Code Mappings in the book of OHDSI. It has the SQL necessary to map from your non standard NDC to a OHDSI standard RxNorm concept.

SELECT concept_id_2 standard_concept_id
FROM concept_relationship
INNER JOIN concept source_concept
ON concept_id = concept_id_1
WHERE concept_code = ‘51927134700’ – DICYCLOMINE HCL POWDER
AND vocabulary_id = ‘NDC’
AND relationship_id = ‘Maps to’;

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