Stream: CCDA / FHIR mapping stream
Topic: IVL_PQ mapping to Quantity
Tushar Nair (Aug 08 2020 at 03:16):
Hello,
I am trying to map some of the elements from C-CDA:Medication Activity template (Substance Administration) to MedicationAdministration resource in FHIR . For MedicationAdministration resource> dosage.dose has the data type-SimpleQuantity. The corresponding element in C-CDA is doseQuantity. My understanding is the data type for this element is IVL_PQ. So when I am trying to map IVL_PQ to Quantity. I am unable to figure out how to map the CDA value if it is a genuine interval-. e.g. doseQuantity-low =2 and doseQuantity-high=3 and unit =mg. In this case when I map it to FHIR 'Quantity' data type - it has got only 'value' but no start or end to capture the low/high interval. Can any one shed light on this? @Lloyd McKenzie @Lisa Nelson
Lloyd McKenzie (Aug 08 2020 at 03:19):
In an administration, the notion of having a 'range' doesn't make sense, as it's a record of what actually happened. The notion of a range makes sense when ordering or summarizing, but MedicationAdministration isn't used for either of those purposes. If you have a range in C-CDA, then you must be looking at a summary and should be mapping to MedicationStatement rather than MedicationAdministration.
Lloyd McKenzie (Aug 08 2020 at 03:20):
(Though if the low and high in the CDA document are the same, you can map to MedicationAdministration - because you effectively have only one value.)
Tushar Nair (Aug 08 2020 at 03:31):
@Lloyd McKenzie thank you so much for the quick response. It makes sense. Is it possible that moodCode of the act has a role to play here. -Let's say its 'INT' then my scenario would hold true? If not, then should we request a change in the spec to change it from IVL_PQ to PQ?
I have that in the C-CDA implementation guide R2.1 (US Realm) and also the latest CDA archiecture page for FHIR.
https://build.fhir.org/ig/HL7/cda-core-2.0//StructureDefinition-SubstanceAdministration.html
Lloyd McKenzie (Aug 08 2020 at 04:12):
If it's INT, then it should map to MedicationRequest - which we use to expose proposals, plans and orders. And MedicationRequest supports Range as well as PQ - the former has both low and high values and maps well to IVL_PQ.
Tushar Nair (Aug 09 2020 at 19:00):
@Lloyd McKenzie , this can lead to some confusion, I mean typically in a Medication activity template - we have the provision to nest Medication supply order template as well. Medication supply order maps to MedicationRequest resource in FHIR. So in principle for a given instance of substance administration in C-CDA we can have a parent MedicationRequest resource and a derived MedicationRequest resource. My understanding of C-CDA Medication Activity template was that INT mood of substance administration simply reflected an intent to administer a medication and was not same as ordering a medication. If both are same when the moodCode is INT, there can be conflicts while converting it to FHIR. Also, shouldn't there be a clear guideline/specification with respect to these kind of edge cases.
Lloyd McKenzie (Aug 09 2020 at 22:04):
MedicationRequest covers orders, plans and proposals. You can differentiate which using MedicationRequest.intent (just as you differentiate in CDA w/ moodCode). MedicationAdministration covers actual administration events (not intentions).
Tushar Nair (Aug 09 2020 at 22:43):
@Lloyd McKenzie thank you so much.
Tushar Nair (Aug 10 2020 at 01:58):
@Lloyd McKenzie -when we map the Medication Activity template to the MedicationRequest template (when moodCode=INT) -how do we derive the requester for the MedicationRequest? Would it be the author of the Medication Activity template OR performer (Medication Activity template) OR should it be the author of the nested Medication Supply Order (if present)
Lloyd McKenzie (Aug 10 2020 at 02:24):
For an INT, author is who wrote the request. Performer is who is being ordered/requested to perform the administration.
Tushar Nair (Aug 10 2020 at 21:15):
Thank you @Lloyd McKenzie :smile:
Last updated: Apr 12 2022 at 19:14 UTC
