I am working on a template for the obstetric process and I have some questions again!
The problem is that I am using the openEHR-EHR-EVALUATION.pregnancy_summary.v0 in my template (and others…) and it fits quite well for some of my variables. I have a variable that fits with an element of the archetype, but it is a Coded text with a set of values (or Internal codes). The thing is that the context of the element fits for my use case (Position of the baby), but the values that I need to have are different.
How would you add those new values? Could I specialize the archetype and delete the values from the parent archetype and add the new ones? Or should I keep them?
Furthermore, I would like to bind some of those values with some SNOMED CT concepts. I have tried doing it from the archetype adding the terminology SNOMED CT and then the bindings for each element, but then I can only do it if the values are added as “Internal codes”, and not as “external codes”.
What is the difference between using internal/external codes?
What does it happen, speaking from a technical perspective, if I change/delete those values from the original/parent archetype and I specialize it?
Thank you very much in advance.
Kind regards,
Laura
Hi Laura! The Pregnancy summary archetype is one of the older archetypes in the CKM that haven’t gone through review and publication, so it contains some older modelling patterns. Your use case where you need to use a local or otherwise different value set for a specific DV_CODED_TEXT element is known in other use cases as well. Newer archetypes have solved the issue by adding another DV_TEXT data type (which can be specialised to DV_CODED_TEXT in a template) to the element. This pattern has also been applied to some elements of this archetype over time, see for example the “Presenting part” element.
I would suggest you add a change request to the archetype, to add a “DV_TEXT” data type to the “Position” element. Alternatively (or additionally), you could suggest the value set you need to be added to the archetype to make it more universally applicable.
We can of course also add SNOMED CT (or any other terminology) bindings to the value set that’s in the archetype.
Hi,
Coming back to this use case, could the addition of a DV_TEXT to elements that have an internal definition be a general workaround applicable to all current archetypes? If I understood correctly, this represents a minor change (in semantic versioning) and it should not diminish the consensus reached in the internal value set, plus it gives room to local use without having to change the archetype.
Generally, yes. Some archetypes are made for very specific use cases such as standardised scores, scales or classifications, and this workaround isn’t as applicable for those.
