In FHIR for the Observation resource there is a a property called category. The category schema consists of 9 types, social-history, vital-signs, imaging, laboratory, procedure, survey, exam, therapy, activity. Is there a community effort or LOINC effort to classify the relevant LOINC concepts into these categories to avoid the default of requiring multiple different stakeholders to duplicate the process? I posted this question to the FHIR Zulip chat as well.
Thanks, Steve
Hello @skassak ,
We are aware of the Observation Category in FHIR and have discussed it internally. It is of interest to us but we have not explored coordination. The laboratory category maps cleanly to our CLASSTYPE but the others are more nuanced. It seems other codes could be mapped programmatically using LOINC’s CLASS and SCALE values.
We do not know of a community effort to classify these. If you are considering the task, we would certainly be interested in your progress.
Good question.
These in FHIR and LOINC are different. LOINC refers to these as CLASSes, while FHIR refers to them as categories. LOINC is more granular and detailed, whereas FHIR is more general. For example, for Laboratory LOINC codes, there are CLASSes for different types of laboratory areas/testing, but also within a laboratory area, distinctions for panel orders. See B.1 Laboratory Term Classes (KB) - LOINC . The LOINC KB has more details as to what is included/excluded from the LOINC CLASSes: 9.1 Additional attributes of LOINC terms (KB) - LOINC Perhaps FHIR would like to adopt the more detailed LOINC CLASSes?
Another aspect is given LOINC includes CLASSES for panel orders and the LOINCs in the class would reflect ORDOBS=Order indicating they are order only LOINCs. HL7 FHIR does correctly use these in FHIR Service Request for Orders. However, HL7 FHIR also represents orders, whether laboratory orders or radiology orders in FHIR Observation as part of FHIR Diagnostic Report. Some also wish to use LOINC order codes in FHIR Diagnostic Report.code. These latter two uses of LOINC panel order only codes in FHIR Observation and FHIR Diagnostic Report are a bit discordant from a mapping perspective as LOINC and HL7 have different ideas of operational definitions and usage. That is the same Complete Blood Count (CBC) or Full Blood Count (FBC) test order name is exchanged using FHIR Observation and FHIR Diagnostic Report and both means are used to “group” the test results and their values contained in FHIR Observations into their appropriate panel orders, especially when multiple panels or reflex panel orders are in a laboratory or pathology report. (I also realize some in HL7 don’t believe that the CBC/FBC is a panel order only and believe panels can be orders or results. There is also a 50-50 split as to what an order is, with some believing reflex orders need only be represented as FHIR Observation and NOT FHIR Service Request, while others of us believe all orders would be represented in FHIR Service Request. Thus, you’ll see the same lab order represented by folks differently in FHIR depending on their preferences/notions.)