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Mapping ICD9 procedure codes (in 2020)

Vocabulary Users
#1

Found a set of ICD9 procedure codes that when mapped to their standard equivalent (SNOMED) are actually sent into the Observation domain (even when the Snomed codes have concept class id of Procedure)
e.g. ICD9 procedure code 89.61 “Systemic arterial pressure monitoring” Athena is mapped to “Systemic arterial pressure monitoring” Athena which is actually a code in Observation domain. Code seems to be clearly a procedure, it has even the Snomed attribute “procedure site”. Shouldn’t these Snomed codes be in Procedure domain?

by looking at older posts seems like ICD9 procedure codes were standard in the past, but not anymore. ICD9 procedure codes are in fact in the Procedure domain.

#2

Hello! Switching monitoring procedures from Procedure to Observation domain seems like a design decision rather than a mistake. It makes some sense, since monitoring regimes are characteristics of patient state and/or medical care rather than unitary procedures that occur on a certain day in certain time.

Domains of SNOMED concepts in OMOP are assigned through setting domains for intermediate ancestors/grouper concepts, and all other concepts inhere domain_id from their closest parent.

Here is the concept that is ancestor to Arterial pressure monitoring, and here is the exact line of code.

@Alexdavv, should we perhaps revisit our conventions for Procedure/Observation distinction, or is current DOMAIN_ID correct?

Finally, from a technical standpoint, it is indeed confusing when domains of source ICD9 concept and standard SNOMED concept differ. DOMAIN_ID of ICD9 concept will be changed to its mapping target next time the vocabulary is updated. Until that happens, for all practical purposes DOMAIN_ID of standard SNOMED concept should be considered as source of truth.

#3

Isn’t this reinterpreting what the intent of the data was? (was stored as an ICD9 procedure)
Looking at the code you provided some of the subsumed standard codes come from ICD10 and are in procedure domain. Maybe we should remap them to ICD10 to get standard procedure codes :laughing:

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