The chatter on the HL7 Strucdoc list server this month claims that two EHRs that are fully conform to the HL7 Consolidated CDA (C-CDA) may not interoperate, so the organizations using them could fail to meet Stage 2 meaningful use requirements. This is, indeed, an issue but the members of the list have conceived a solution and are anxious to start. A number of contributors representing major implementers are willing to contribute. In fact, the only concern about the solution is to find a way to do it once and right, rather than have a disjointed set of attempts.
The issue: It is not always clear how to express some clinical thoughts in the C-CDA, at least for some developers. Some examples include ”allergic to latex but no known allergies to medications”, “the patient states she has no allergies” vs “we don’t know if the patient has allergies”, “the patient believes he is allergic to penicillin” vs “a physician has reported anaphylaxis as a reaction to penicillin.” Sometimes there is more than one way to express the same clinical thought in C-CDA-compliant XML. If the system that creates the document expresses it one way, but the system that is interpreting the document is looking for a alternate expression of the clinical thought, it may miss the data altogether.
The Solution: The jointly conceived solution is to publish examples of the XML used by the C-CDA to represent hundreds of important clinical thoughts in a wiki. The wiki has the double benefit of showing newbies how their XML should look and helping all implementors know the preferred choice when there are multiple ways to express a clinical thought.
There is general agreement about the solution and there are a lot of enthusiastic ideas about how to go about it. This is good because the industry needs these examples right now. The developers are working on the code right now that will be the heart of their implementations for Stage 2.
I expect that the at the HL7 Working Group meeting next week the Structured Documents group will be able to settle on a single approach and the HL7 Board and ONC will come forth with the nominal funding that it takes to mount a wiki and facilitate the process of creating and deciding among examples of clinical thoughts. The volunteer spirit has never been higher and the volunteers are pursuing a critical goal. If they end up spinning their wheels for lack of support, the entire notion of semantic interoperability could get a black eye.