Stream: IG creation
Topic: Resource reference Must Support
Sarah Gaunt (Jun 23 2021 at 21:05):
We've had a query from @Brett Marquard: "Observation.hasMember has Must Support at element level, not individual Resource reference, which must systems support?":
image.png
I see that US Core uses the http://build.fhir.org/extension-elementdefinition-type-must-support-definitions.html extension to add must support to references where not all references are must support:
image.png
In our case, we are wanting all of the references to be Must Support.
Is it sufficient as it is? Or do we really have to add the extension to each reference to make it look like:
image.png
Grahame Grieve (Jun 23 2021 at 21:07):
to answer that question, I think you do.
Sarah Gaunt (Jun 23 2021 at 21:08):
I just saw this in the extension too: "Comment:
An element may be labelled as must support. This extension clarifies which types/profiles/targetProfiles are must-support. It has no meaning if the element itself is not must-support. If the element is labelled must-support, and none of the options are labelled as must support, then an application must support at least one of the possible options, but is not required to support all of them."
Sarah Gaunt (Jun 23 2021 at 21:08):
So is this only for when you have multiple references?
Sarah Gaunt (Jun 23 2021 at 21:10):
I guess it is because if you only have one option then "an application must support at least one of the possible options".
Sarah Gaunt (Jun 23 2021 at 21:11):
So this is fine:
image.png
And means that you must support the US Core Patient.
Grahame Grieve (Jun 23 2021 at 21:19):
yes
Brett Marquard (Jun 24 2021 at 00:55):
Here is an example where one reference is MS but others are optional...
Brett Marquard (Jun 24 2021 at 00:55):
Richard Townley-O'Neill (Jun 29 2021 at 00:44):
"Comment:
An element may be labelled as must support. This extension clarifies which types/profiles/targetProfiles are must-support. It has no meaning if the element itself is not must-support. If the element is labelled must-support, and none of the options are labelled as must support, then an application must support at least one of the possible options, but is not required to support all of them."
IMHO this needs to be included with the IG's general statement of what must support means, not just in a comment on a core extension.
Richard Townley-O'Neill (Jun 29 2021 at 23:28):
The bolded text is fine for writers: support at least one option of your choice. What does it mean for readers? It must mean support all.
That needs to be made clearer.
Last updated: Apr 12 2022 at 19:14 UTC
