Question about non-standard to standard code mapping... is it always one-to-one?

[mr.nim.li]

In one discussion, our team has decided that when we are mapping the codes, we should map the non-standard code to standard code, only in one-to-one basis. Part of the reason is based on the discussion here:

Mapping vague terms

Hi everyone, We are working on mapping our pathology data into CDM however we have come across few terms which are vague and don’t have any particular answer to them. for example Number involved, Number examined, etc. We are facing difficulty in mapping terms like this Please let me know if you have any suggestion. Additionally I also want to ask, can we use two codes for a single term for example I have a term “involvement status of an organ” so can I use two different codes for it like “inv…

However, when I am mapping the code now, I can see why we may want to map the code in one-to-multiple basis, rather than one-to-one. For example, in our pathology system (CAP vocabulary), we have in a record:

Question - “Microcalcifications (Note P)”
Answer - “Present in both carcinoma and nonneoplastic tissue”

I can find in the CAP vocabulary the concept id of this question with the concept id “1111844”, which in turns is mapped to another standard code, with the concept id “3188191” under the Observation domain. So, I thought I could store the “answer” as the associated “observation.value_as_concept_id” field.

But looking into the CAP vocabulary, I cannot find the CAP code of this specific answer. Instead, I can find:

1. “Present in nonneoplastic tissue” (non-standard) with concept id: 1112720, which is mapped to another (standard) code with concept id “4296694”; and,

2. “Present in invasive carcinoma” (non-standard) with concept id: 1111847, which is mapped to another (standard) code with concept id “4287934”

I wonder if I map the CAP code of this particular Answer to both of the standard codes - “4296694” and “4287934”, will it cause any issue, or any concerns? Or other alternative we should explore? Any comment is welcome.

Thank you!

[Agnes_Wojciechowski (Agnes W)]

@mr.nim.li

we should map the non-standard code to standard code, only in one-to-one basis.

This is wrong. The mapping to multiple standard codes is a common practice and was conceived on purpose to best capture fully the medical meaning. By all means map to both answers to capture that comprehensive meaning.

[Agnes_Wojciechowski (Agnes W)]

I found the exaple in The Book Of OHDSI chapter 5.3.1

Chapter 5 Standardized Vocabularies | The Book of OHDSI

Some mappings connect a source concept to more than one Standard Concept. For example, ICD9CM 070.43 “Hepatitis E with hepatic coma” is mapped to both SNOMED 235867002 “Acute hepatitis E” as well as SNOMED 72836002 “Hepatic Coma.” The reason for this is that the original source concept is a pre-coordinated combination of two conditions, hepatitis and coma.

[mr.nim.li]

Thank you! This is very helpful!!