Structured Document Architecture
(main entry to be created)
For other architectures based on HL7 artefacts see HL7 Messaging Architecture and Services Oriented Architecture.
FAQ
CDA R2 using a non-XML ITS
- In how far is CDA R2 "abstract"? - In other words: if one were to attempt to apply a different ITS (assuming there was one, e.g. ASN.1 or CORBA), what would the "open issues list" look like?
(CDA R2 Documentation) "Specific enhancements to the CDA Schema, above and beyond those defined in the HL7 V3 XML ITS, are described [..] in CDA XML Implementation (§ 6 )." Section 6 states: "The CDA Narrative Block, which is the XML content model of section.text, is manually crafted, as described above (see Section Narrative Block (§ 4.3.5 ))."
(Charlie McKay) The way that references between parts of the narrative block and the structured content are done in an XML specific way (reasonably enough because HL7 itself -as an standard- does not have an IIref mechanism agreed yet). This is the rationale for the schema edit: Add "ID" attribute, of type XML ID, to Section, ObservationMedia, RegionOfInterest
If one were to create a different ITS then the current CDA R2 XML schema or the manual tweaks made to them don't actually matter that much, as long as the tweaks didn't introduce new abstract concepts or constraints. One would start from the HMD (or in future: the MIF), additional work would be required (from an abstract point of view) in addition to the HMD to make it work:
- add the constraints as defined for Narrative Text (in an abstract fashion - strucDoc will hopefully create one at some point in time)
- deal with the IIRef issue in some way
