I propose that OSHCA join HL7 for $300 and that Thomas be our
representative to that group. I've got $50 on the table. Any takers?
I congratulate Thomas for the leg work that he has done and undertaken
to do. It is entirely necessary for the success of open source in
medicine.
Thomas, is GEHR open source and will it use an open source development
environment? Do you use a version of Eiffel that is open source? I
know that this recapitulates a question from Brian, but it would be good
(no pun) to hear the exact details.
Thomas, the USAM is going to be/is already embodied in the PRA. Seeing
that PRA is HL7's explicit medical record storage initiative, how does
it interact with GEHR, specifically the XML philosophy?
In that last analysis, however, the standard is more important than the
embodiment. Thanks for this excellent work!
John
Thomas Beale wrote:
>
> This is a bit premature, but what the hell.....
>
> I have been studying the USAM (unified service action model) - the
> clinical part of the HL7 v3 RIM. While (naturally!) I don't
> necessarily agree with everything I have read, it is a pleasure to
> read, due to its clarity. People here might be interested in a few
> early conclusions:
>
> * HL7 is more process-oriented than GEHR. This is not surprising,
> given its hospital/pathology origins, and the general strength of
> health IT in the US in hospitals rather than primary care. In
> Europe, Australia/NZ it is the reverse, and consequently GEHR was
> originally conceived for primary care and hospital use, but was
> more knowledge oriented (GPs care less about micro-process than
> do hospitals).
> * This philosophical and historical difference does not mean that
> GEHR and HL7 are incompatible; on the contrary, there are so many
> areas of compatibility, I was surprised myself. Another way of
> stating the different philosophy is that GEHR makes the EHR
> explicit, whereas HL7 models the whole process of health care,
> and (I assume) would see the "EHR" as a kind of constructed view
> of an HL7 system.
> * A challenge for HL7 is to make definitional and result
> information more clearly available (i.e. filter out some of the
> more detailed process stuff) for clinicians to use; a challenge
> for GEHR is to include more process (currently underway - care
> plans and pathways are being modelled).
> * USAM uses "mood" to differentiate between the meanings of
> different kinds of services - definition, intent, order, event (=
> satisfied order), goal (a predicate mood). The mood variable is
> central to HL7 information being able to properly carry the
> important semantics of natural language. In some ways mood
> simplifies the model (reduces number of classes etc) but I think
> a bit more work will be required to make the whole model
> comprehensible, since mood interacts with other variables like
> "status", and meanings have to be assigned to every mood X status
> combination. But.... it is clear that the purpose of mood is
> important. In GEHR's knowledge based approach, there are a
> surprising number of equivalences (following in the form of hl7 =
> gehr):
> o definition mood = PROPOSITION_CONTENT
> o intent mood = PRESCRIPTIVE_CONTENT, status = defined
> o order mood = PRESCRIPTIVE_CONTENT, status = ordered
> o event mood = PHENOMENON_CONTENT
> * Service status describes a state model (new, held, cancelled,
> active...... completed), which corresponds to GEHR's
> PRESCRIPTIVE_CONTENT.status, and also a status variable in a care
> plan.
> * Many of the service who/what/when/where attributes have a direct
> correspondence to the GEHR context attributes (ANY_CONTEXT,
> PHENOMENON_CONTEXT etc)
> * A crucial aspect of GEHR is versioned transactions, enabling
> prior states of the record to be reconstructed. USAM mentions
> "snapshots" of the state of business objects at each stage in
> their cycle, for foresnic auditing - the same purpose as GEHR.
> This is encouraging, as it means that there is likely to be a
> direct equivalence for this once HL7 details more how it will be
> implemented.
> * Almost all data types have equivalences in GEHR and HL7, and I
> suspect mapping these at least will not be too traumatic.
>
> It's early days yet, and I intend to publish a proper review of
> GEHR/HL7/Corbamed/CEN at some stage, including an ontological
> comparison (i.e. structural comparison of the philosophies). So the
> above is just to whet the appetite.
>
> I am hoping my visit to Cleveland in 2 weeks will help the effort for
> true interoperability along, by finding a path for harmonisation.
>
> - thomas beale
>
