Grahame and Jobst and I (and, I am sure, also Thomas) agree that there is "benefit in commonly agreed semantics". The thesis that has served as the central pillar of this blog since its inception, however, is that after 14 years of development effort, and after so many failures, we should finally accept that the RIM is not able to serve as basis for the needed commonly agreed-upon semantics.
HL7 Watch and others have provided considerable documentation that the RIM is both counter-intuitive and unnecessarily complex; that it is thus difficult to teach and difficult to document (and thus inconsistently documented); and that it is therefore difficult if not impossible to implement.
Moreover, multiple arguments have been provided to demonstrate that, even if it were implemented, the RIM would still not bring about the end which its defenders seek, namely: consistency of semantics. This is because the RIM's own semantics is so counter-intuitive, and thus so inconsistently documented, that its different users will inevitably produce semantically inconsistent implementations, thereby resurrecting the very problems which had led to the conception of the RIM in the first place.
We have learned much in the field of semantics in the 14 RIM years, and what has been learned can now be used as the basis for a better and simpler solution. It is time to start again.
Postscript 4/2/2011, 11:19 AM
Only in the final paragraph does Graham address my specific arguments concerning what so many now see as the dire state of HL7 V3:
Not sure what 'fractional' means when applied to criticism. I can well understand that many of the criticisms on this blog will seem 'marginal' to some of those who are caught up in the attempt to use and maintain the HL7 standards. On HL7's FAQ page, we find an odd entry headed "HL7's Mission", which reads as follows:
HL7 provides standards for interoperability that improve care delivery, optimize workflow, reduce ambiguity and enhance knowledge transfer among all of our stakeholders, including healthcare providers, government agencies, the vendor community, fellow SDOs and patients. In all of our processes we exhibit timeliness, scientific rigor and technical expertise without compromising transparency, accountability, practicality, or our willingness to put the needs of our stakeholders first.It is evident to those, such as myself, who are viewing HL7's processes -- for example as illustrated by some of the more untamed contributions to the HL7 Vocabulary forum -- from the outside, that they exhibit a marked shortfall in timeliness, scientific rigor, transparency, accountability, and practicality. Why is this so? In part, surely, because of those marginal issues -- such as the inconsistency and counter-intuitive nature of the RIM -- which I have been attempting to draw attention to on this blog.
And what is the alternative?
I hope to address this question in more detail in a later post. But for the moment:
- First, recognize that the RIM rests on a series of rather simple confusions (for example between a disease and its diagnosis, between an action and its documentation, between an entity in reality and information about that entity in some record).
- Second, replace the RIM backbone hierarchy with an ontology that is not subject to these confusions, for example in the way that this is done in the Ontology for General Medical Science, which is based in turn on Basic Formal Ontology.
- Third, study the principles of Referent Tracking.
Again: if I am right, then the RIM will, sooner or later, have to be abandoned -- cost what it will. The groundswell of criticism can be held back for a bit longer, perhaps, through application of the existing strategies used to cow critics into anonymity. But what makes the case of Elliot Muir so interesting is that these strategies, too, are no longer working.
Postscript April 12, 2011
An interesting report on national health reporting standards in Norway contains the claim that:
"Most European countries that make use of HL7 messaging standards for new purposes uses HL7 version 3. This applies in particular [to] Britain, Germany and the Netherlands."
In fact, however, it seems that there is know one in Germany who is using v3 messaging, although CDA is in use in some places. In the UK there is some v3 legacy, but there seems to be no new development; rather, new work is being done within the framework of the 13606-based Logical Reporting Architecture (LRA), which seems (to me at least) to be a much more coherent modelling effort. Netherlands, it is true, is still using v3 messages, though it is not clear that they are actively developing anything new. And outside of those three countries? In Norway, for instance, plans were indeed announced to mandate v3 - solely, it seems, in light of its status as an 'international standard'. But from the above-cited report it seems that Norway has pulled back from the brink. In the rest of Europe it is CDA that is being used, or 13606 or LRA.
In a comment by Rene Spronk (provided in full below), the question is raised as to HL7 Watch's view of openEHR in light of the fact that the latter has certain similarities with HL7. openEHR, too, I believe, has need of a more sophisticated upper ontology-based approach: it is thus far marked by a lop-sided focus on information models at the expense of representations of reality of the sort which ontology can provide. But there are leading figures in openEHR who would agree with this diagnosis, and I remain optimistic that openEHR - and similar ventures under the CEN-13606 heading - will take the steps needed to rectify problems in this regard. The HL7 community, unfortunately, which is currently advancing the RIM as an 'upper ontology' in the context of its new 'Services-Aware Interoperability Framework’ or SAIF, still gives no evidence of having understood what a well-designed ontology might look like, and what such an ontology is able to achieve. As addressed at length already elsewhere in this blog the RIM has fatal shortcomings not only because it contravenes the very basic rules of information modelling, but also because its backbone taxonomy of Act, Entity and Role is too narrow to allow serious ontological work.
Referring to an earlier link posted by Rik Smithies listing 22 known software implementations based on the RIM, Rene argues that
This is just the tip of the iceberg in terms of known organizations that voluntarily embrace the RIM as either a persistence model or a in-memory business layer model. This is mainly done for research, public health and DSS purposes, although we've also seen implementations to support classic on line transaction processing applications. ... Calling the RIM "fallen" when at the same time it is increasingly being embraced as an internal model in all sorts of applications - your call, but curious to say the least.
Postscript August 3, 2012
The inevitable outcome of wide scale adoption of [the Design by Constraint] technique is chaos. Different implementors want to live at different points on the general <-> specific curve, and there’s a variety of options to attempt to externalise costs from one implementor to another.
There’s various approaches to handling this. You can be like HL7: put your head in the sand, claim that it all works (in other words, externalise the costs), and then be real confused about why your brilliant idea isn’t actually solving all the problems in the world. ...