When transforming archetypes from other standards to openEHR the obligation of creating an ITEM_TREE implies a semantics that in origin may not be the case. Instead generic CLUSTERS and ELEMENTS should be allowed, as grouping classes like clusters or organizers are usually optional in other standards.
e.g. if we have originally An ENTRY->ELEMENT subtree then an empty ITEM_TREE must be created, when probably we could just reproduce the original structure with GENERIC_ENTRY->ELEMENT
The more generic grouping structure openEHR has is CLUSTER. In fact in CKM cluster is used as the generic class for this kinds of archetypes and not item_tree. Using item_tree means that up to two new classes must be created to represent simple structures.
See attached images in which a valid 13606 structure is translated to openEHR with the minimum classes possible. Notice the extra classes needed in openEHR (and that the semantics is probably not the same)
If ITEM abstract class is used instead of ITEM_TREE then either CLUSTER or ELEMENT can be used and then an structure like GENERIC_ENTRY->ELEMENT would be correct.
This kind of problem also shows ups in CDA to openEHR transformations.
Probably is also worth noticing that ITEM_TREE, ITEM_TABLE, ITEM_LIST & ITEM_SINGLE model is intended to be replaced with a more generic CLUSTER model in future RM versions.
Base don the original intent of the GENERIC_ENTRY, I support the proposal of using ITEM instead of ITEM_STRUCTURE.
+1 to Heath
I support this.
Yes, seems like an appropriate change.