Scores or scales with mixed data types or explicit NULL values

I’m increasing not sure that null flavours should ever be part of clinical modelling at the archetype level. No information, masked, unknown (in information context, as opposed to a clinical determination of unknown) and not applicable should be available on all data points at all times, including a reason for each null.

The current tooling only supports removal of the remaining null flavour options in order make one explicit or emphasised, when in fact all null flavours should be available all the time. Making ‘unknown’ an option in the archetype for a value set, should not remove the ability for ‘not applicable’ or ‘masked’ to be available in a template or implementation scenario.

Agree about another thread being a better option at this point.


So, the solution is … what?
a) Use Ordinal and value ‘99’ for now or;
b) Wait for changes in spec’s as described by Sebastian, then change to DV_SCALE or;
c) Change to DV_SCALE now, and fudge it to something in line of ‘99’ as alternative a)

Just a slightly confused…

The problem will be that if you do anything right now, it will require a breaking change to the archetype later, other than using the ELEMNT.null feature. or adding a temporary DV_CODED_TEXT alternative.

I suggest @sebastian.garde and I take it to the SEC and see if we can get a quick Spec update agreed. It would also need a change in tooling and ultimately in the CDR validation.

Is there a really pressing need?

If this can go through the SEC quickly it would be appreciated. This archetype is going through review ready for near future implementation. And there is another archetype with this same modelling issue that will likely follow through review in the next few months.


Agree, it would be great if this could be fast tracked. However, if I understand correctly it’ll have to be changed in tooling and implementations too?

Yes, this change would definitely not work out of the box for CKM and pretty sure also not for any other tool.


And it will also need a change in CDR validation


So it will take months to be able to use the proposed design. Which means we’ll make NANO archetype as alternative a) in my post above, and leave it in v0.

Which, by the way, was done some days ago: Observation Archetype: Neurologic Assessment in Neuro-Oncology (NANO) scale [openEHR Clinical Knowledge Manager]