I was intentionally careful to say ‘invalid relationships’ because there seems to be some cases where we ignore the INVALID_REASON on concepts when doing the mapping (such as NDC -> rxNorm, you look for the valid relationship, but ignore the ndc might be invalid…I think I’m remembering that properly).
I would like to drop validity information and consider all information in the vocabulary ‘valid’. In the same context, I’d like to get clarification on the valid_from -> valid_to. It seems to me that when doing the ETL mapping, we look for the NDC code that was the valid source concept on the date of the exposure (it could be many years int he past) and then look for the corresponding relationship that is valid for that same period of time that maps to the standard concept that is valid for that period. That sounds like a lot of ‘date validity’ checks but I kinda like it. We were doing a mapping exercise for a study and there was some debate about the purpose of one of the ICD9s that was involved in the study. Some people thoguht it was appropriate, others thought it was not, but as it turns out, they were both right: there was an ammendum in somewhere around 2010 that chnaged the intent of the ICD9 code, meaning that before 2010, it would have mapped to one standard concept, and afterwards, a different one…