Thomas et al The point you make here about the CEN ENV13606, HL7 CDA and HL7 RIM is one I have heard you make before. I always refute it whenever I have time so here I go again ...
HL7 RIM is a way of representing clinical information to be communicated. The naming of the class "Act" leads to view that this is to do with process rather than documentation. However, when you study the definitions and use cases you find that HL7 Acts are prehaps poorly named but actually refer to class constructed to convey documention about things that have happened, may happen or are planned to happen etc. They are documentation not representations of process. CEN ENV13606 consisted of four parts. Of these the first part was high level architecture and the last was about specific architecture. The entire focus (and I speak with a little authority as the leader of the fourth group) was on communication. Indeed the word communication is part of the title of the entire ENV13606 standard. The GP2GP Project is using the ENV13606 architecture but rather than expressing this is a separatist manner is seeking to apply the HL7 Data Types and classes. This is not just for the fun of science but rather on the basis that EHR communication is one of many types of communication flowing between clinical systems within the UK. The idea of migrating these to a common implementation technology specification is the primary driver in applying the HL7 methodology. There have been problems in this approach but crucially none of these relate to any supposed conflicts between the objectives of the HL7 RIM and ENV13606. It would seem such differences are at worst purely theoretical in nature. From the perspective of representing the core structured and coded semantics of current records used in the UK the application of HL7 methodology has resulted in a more robust approach than the ENV12265 or ENV13606 work alone. HL7 CDA has three levels. The first of these is purely documents in the marked up text sense - and it is the only one realised as a standard so far. Level 3 is now under debate and Bob Dolin's excellent proposals for this express the structured content of the record using the components from the same HL7 RIM that we are using as the basis for GP2GP. Indeed Bob's proposals have the appearance of a genericised version of the GP2GP model. Certainly there are some points to discuss between them but the two approaches are convergent rather than in any sense truly distinct let alone divergent. I stress again the focus of HL7 RIM and ENV13606 and the GP2GP project are communication. The merger of the methodologies has been helpful and fruitful. I understand the general nature of some theoretical comments made on the openEHR list. However, for all of us the challenge with limited time and mental bandwidth is to give adequate detailed consideration to the points of commonality. Thus Thomas's observations about the "correct mapping of HL7 Acts" is correct in so far as it goes but incomplete in that a composite of recorded events (aka an entry) can also be safely and effectively represent in these structures. This mapping is the way that CDA and GP2GP both use and in both cases it seems to be fit for purpose. Kind Regards David Markwell The Clinical Information Consultancy 93 Wantage Road, Reading, Berkshire, RG30 2SN, UK Tel: +44-118-9584954 Mobile: +44-7850-600-955 Web: http://www.clinical-info.co.uk Mailto:david at clinical-info.co.uk > -----Original Message----- > From: owner-openehr-technical at openehr.org > [mailto:owner-openehr-technical at openehr.org] On Behalf Of Thomas Beale > Sent: 18 December 2002 16:26 > To: Pete Horsfield > Cc: openehr-technical at openehr.org > Subject: Re: openEHR XML schemas > > > > > Pete Horsfield wrote: > > >Matius > > > >It is probably worth you investigating the UK GP2GP records transfer > >project which is using an HL7 based XML schema to underpin records > >exchange between GP systems in the UK: > > > >http://www.nhsia.nhs.uk/gp2gp/pages/default.asp > > > >The GP2GP schema is not, strictly speaking, an open EHR > schema but must > >be highly relevant. > > > It is as an idea, but it has mixed up the notion of the HL7 RIM ( a > model of acts) with the CEN model of documentation, which is very > similar to the CDA and the openEHR concepts. The requirement > for GP2GP > was to get information from one GP system to another, where there are > about 3 kinds of system to my knowledge, and the information > is based on > CEN 13606. The appropriate way to do this would have been > simply to use > the CEN EHR_EXTRACT (or use newer versions of this concept > from the CEN > 13606 revision proposals or openEHR), or even to use HL7 CDA. > However, > recoding CEN EHR data as an HL7 message does not make any > sense, and I > wonder about data safety, given the contortions one has to go > through to > turn what is a simple model of Extract, Folder, Composition > etc into a > bunch of Acts containing moods, activity times and suchlike > which have > no meaning for these components in general. The CEN model is > already a > formal model, and the attempt to recode it in terms of > another model is > contrary to normal modelling practices. > > We have made a lot of efforts to perform a proper analysis of these > issues, which show where context attributes should go, which are > documented in the CEN 13606 revision, and at more length in > the "Design > Principles" paper on the openEHR website. > > The correct relationship between the HL7 model and a "model of > recording: such as CEN, CDA or openEHR is that Acts and Act > relationships map to Entrys and links - i.e. the HL7 concepts > document > something in the real world, and this becomes the "content" of a > document - which is done at the Entry level. > > > regards, > > - thomas beale > > > > - > If you have any questions about using this list, > please send a message to d.lloyd at openehr.org > - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
