Just what is HL7 v3?
Nov 2, 2011Quoting from Karen Dearne in The Australian:
NEHTA has specified technologies that are either immature or not widely used, particularly the secure messaging standard HL7 version 3 and its accompanying clinical document architecture.
Note that this article that is really all about the competing pressures I talked about in my last post, so I’m not going to discuss any of them. Nor am I going to discuss the question of “immature or widely used” - see here and here for past comment, and it’s clear that CDA is now widely used by normal definitions of the words “widely” and “used”.
Instead, I’m going to take up the question of just what is v3?
The implication of “NEHTA has specified the secure messaging standard HL7 version 3 and its accompanying clinical document architecture” is that NEHTA has specified both v3 and CDA. This is causing ongoing confusion, and we need to choose more clear language. (btw, this quoted sentence demonstrates another confusion: NEHTA created an Australian Standard called “Secure Message Delivery”, which has nothing to do with HL7 v3, and nor is HL7 v3 a secure messaging standard - the sentence lost at least a comma somewhere through the publishing process).
HL7 v3 is an umbrella framework for publishing multiple different specifications. It’s not exactly clear quite what defines v3, but it seems that at least operationally it means, models derived by constraint from the RIM, whether not those models are provided through messaging, documents such as CDA, or services as published in assooiation with the OMG. (We’ve had some discussions about formalising that definition, but I’ve not noticed it happen). So there’s multiple technical standards as part of v3:
- v3 Messaging
- CDA
- IXS, RLUS
These are all v3. But the first one is “v3” for a lot of people. So in a sentence where you say “specifies v3 and it’s accompanying CDA”, most people take this to mean, v3 messaging and CDA. But this is not the case: NEHTA has not specified v3 messaging (and while I don’t make policy statements for NEHTA, I can say that there’s zero interest in using v3 messaging in NEHTA). NEHTA has specified CDA as content for some clinical use cases.
This is a heads up - there is much confusion around this subject. For anyone in Australia I say, at this time, please don’t use “v3” without specifying what you mean. The policy makers and the journalists are having a hard enough time differentiating all this profusion of standards as it is.