One issue that we’ve run into in rolling out our OMOP instance to the research community is that of interface vs. reference terminology. We’ve been using the SOURCE_VALUE columns to insert the reference terminologies from the source systems - diagnosis_source_value gets the ICD-9/10 code, measurement_source_value gets the LOINC code, procedure_source_value gets the CPT code, etc.
However, we’re finding more and more that users want (or need!) to build queries based on interface terminology, rather than reference terminology. Take platelets, for example. There are multiple LOINC codes for platelet counts - without a clear correspondence between the interface terminolgoy and the reference terminology, users have no way to know which one corresponds to the platelet values they see on a day-to-day basis (for example, the one that returns from a standard auto differential) and which one corresponds to an arcane measurement that’s barely ever used in clinical practice. They could theoretically run queries to see which are ordered more than others, but that requires extra work and still doesn’t establish a one-to-one correspondence.
Procedures also throw this issue for us - we use non-standard CPT codes for many common procedures (including auto differentials), which don’t get mapped to CONCEPTs. We can insert the non-standard codes in procedure_source_value, but without the interface mapping, again, the user has no way to draw a conceptual linkage from the “AUTO DIFFERENTIAL” they see in a patient’s chart and the “01006.123” they see in procedure_source_value.
One way we’ve explored addressing this is creating views called “MEASUREMENT_LOOKUP” and “PROCEDURE_LOOKUP” that handle this mapping - allowing them to see which LOINC codes or CPT codes correspond to which interface terminology entries. This is nonstandard, though, and we’d love to be able to handle this solely within the confines of the CDM standard tables.
Has anyone else confronted this issue? What are some of the techniques you’ve applied in trying to navigate the gap between the interface terminology researchers and clinicians deal with in the EHR frontend and the standardized reference terminologies we use to populate the CDM tables?