And, below some obtuse Interoperababble from another presenter:
HL7’s Implementation Guide for CDA Rel 2, weighs in at an eye-watering 595 pages of implementation spec, and this is known as a nonstarter due to the imposed allegiance with V3 and a complex RIM. Our experience with numerous CDA document instances also demonstrates the poor level of support mainly around CDA Level 1, as we found most documents improperly formatted. And CDA instances suffer from an impedance mismatch that makes it difficult, if not practically impossible, to map between them. Finally, the FHIR API doesn’t even have a simple call to return everything about a single patient, one has to iterate through fine-grained link lists, and developers must reconstruct a patient's object.Lordy.
Read the antecedent Jason report here: "A Robust Health Data Infrastructure." (pdf). See also my Interoperability rant here. Finally, see the story that put me on these doozies: "ONC Task Force Seeks Answers to Interoperability."
More to come...