This specific post references source data coming from lab draws & results/lab cultures/microbiology specimens. So, I would also look at the domain_id for your lab draw codes. The source has one row of data which will ETL to 3 rows in the OMOP CDM. Two belong to the Measurement domain and one belongs to the Specimen. All will be related via the Fact Relationship table. There is some discussion about the appropriate relationship_concept_ids for these relations. See this relevant post.