I strongly recommend looking at the way terminology services are handled in FHIR.
A ValueSet Resource (ie the subsets you're talking about) has a URI, so that it can be replicated in a local TS and referenced by it's well-known identifier rather than just a URL. It has a definition (which may be an explicit list of codes, or based on filters (ie rules) - for SNOMED CT you can use the Expression Constraint Language), and it also has an expansion - the enumeration of the codes that satisfy the definition with respect to a particular version of the underlying code system. There are operations like $subsumes to test the relationship between two codes, and $closure to incrementally build up a subsumption graph in the client for subsets of codes (those actually in the patient records) to support efficient query. For SNOMED CT, a 'code' may be a single SCTID or a post coordinated expression. michael -- Dr Michael Lawley Principal Research Scientist The Australia e-Health Research Centre http://aehrc.com/ work: +61 7 3253 3609; mob: +61 427 456 260 ________________________________________ From: openEHR-technical <[email protected]> on behalf of Diego Boscá <[email protected]> Sent: Monday, 12 September 2016 4:32 AM To: For openEHR technical discussions Subject: Re: SV: More generic reference model I mean, I can see that there can be valid queries to known terminology services, I'm not against that. In practical terms however, you can't always expect to have all the access that you want to a given external service. e.g. I was banned from W3C once for launching a transformation (more like 10k...) that depended on a online schema. I can imagine that could even be worse for terminology services (downtimes and maintenance aside). That's why I said standard (explicit?) expression definitions should be preferred when available 2016-09-11 20:21 GMT+02:00 Thomas Beale <[email protected]>: > Not an unreasonable point of view, but it sort of implies that there are / > will be no well-known / reliable terminology value sets out there - only > specific value sets inside specific terminology services. > > > On 11/09/2016 19:10, Diego Boscá wrote: >> >> The problem I see with depending on a given terminology service is >> that the code you are defining may or may not be known by the >> terminology service. This could be ok for templates, but not for >> archetypes. In my opinion generic archetypes should be based on known >> syntaxes rather than in specific queries to terminology services >> whenever is possible >> > > > > _______________________________________________ > openEHR-technical mailing list > [email protected] > http://lists.openehr.org/mailman/listinfo/openehr-technical_lists.openehr.org _______________________________________________ openEHR-technical mailing list [email protected] http://lists.openehr.org/mailman/listinfo/openehr-technical_lists.openehr.org _______________________________________________ openEHR-technical mailing list [email protected] http://lists.openehr.org/mailman/listinfo/openehr-technical_lists.openehr.org
