HCPCS codes change their meaning over time

[Dymshyts (Dmytry Dymshyts)]

We are still discussing the details here:

Important! Change in rule for CONCEPT records: concept_code is not longer unique within some vocabularies

Right. We use them only for development purpose. So in production those fields seems to be redundant. Anyway, I would keep them for cases like these: You create custom relationships originating from 2 billion concepts, then you fix them and fill valid_start/end date and invalid reason. So, it’s fine to give the users CONCEPT_RELATIONSHIP with these fields, so they can use them. Look, you have concept A (1970 -2017) and B (2017 - 2099). In both cases you need to check the valid_start/end date…