In the London UCP , we have been asked to support ‘Date of Diagnosis’ = ‘unknown’ as distinct from an empty field i.e. a positive assertion that the question has been asked but the date is unknown.
TBH I do struggle to understand why this distinction is quite so important in the context of a Problem list, and I have pushed back a little on the requirement.
However, if it does become clear that this is necessary, I think we do probably have to go down the ugly road of ELEMENT.null, which the UI will have to inject.
Has anyone come across this date= unknown issue before? In nearly 20 years of modelling, it is the first time it has come up for me!
For background, every ELEMENT in an archetype can be forced to accept a null instead of a data value, with one of a set of null_flavour codes e.g unkown, No information. It is generally a bad fit for clinical unknowns, so it is normally used only to escape situations where an ELEMNT is mandatory but for some technical reason, the field cannot be completed.