Hi Gerard, a very useful document indeed...The approach is quite interesting and solid; no questions mathematically (at least in my MD mind!). I was thinking about brainstorming about finding some metrics (logical and feasible to experiment) to test those issues. Such as:
Maintenance: comparison of lines of code during maintenance, frequency of support requests and time to fulfill them, user satisfaction surveys, cost figures and so on for maintenance Interop: your points (i.e. # of interfaces to be implemented, # of messages and schemas), number of transactions, reused fragments, number of hops during a shared care event (i.e. how many systems particular data (EHR extract?) travels, how many users access it and how..... These are just initial thoughts and I am sure there are already better ones out there. I think, seriously, such studies would be very beneficial for community in convincing interested parties. -koray Gerard Freriks wrote: > HI, > > Via the Url a PDF/presentation with some calculations. > No message standard, any message standard and the two-level-model > paradigm, are compared. > http://tinyurl.com/26hlch > > Gerard > > > > On Feb 6, 2008, at 9:28 PM, Sam Heard wrote: > >> Hi Koray >> >> I think we will have to come up with some metrics that are relevant >> as it has not been done before in the domain space. Clearly modelling >> at two levels is a common approach - relational databases model the >> idea of tables with rows and columns, linking keys, data types and >> indexes. The domain information is expressed in terms of these rows >> and columns. Many systems driven on metadata do the same thing. What >> is new about openEHR is a generic approach to allow any base model >> to be constrained through the use of ADL. The result is that the base >> model can reflect the general business rules and the fixed >> information constructs - the archetypes the domain knowledge and how >> it is represented in terms of the base model. The approach relies >> only on getting sufficient expressivity at the base level to make the >> split efficient and safe. >> >> The comparison in health care at present is with HL7 version 3. This >> has a base model (RIM) from which a new model, an RMIM, is >> constructed (level 2). The difference is that RMIMs are constructed >> with alterations to the RIM classes (which are renamed). So we now >> have a new class based on a pattern. The semantics of the RMIM is a >> mixture of RIM and RMIM and difficult to untangle. CDA is using >> templates in the same way as openEHR uses archetypes - to express >> some domain content. As CDA is already committed to XML, the means of >> further constraint is limited - hence the use of schematron and other >> devices. >> >> I guess the first metric that we could consider is the speed at which >> domain concepts can be modelled and the level of human intervention >> for documentation and maintenance. The UK NHS, which has the most >> experience of both, has found openEHR far more efficient to use than >> MIF template constraints on HL7 CDA. Vendors are cautious and have >> little experience of openEHR directly as yet. >> >> Clearly archetypes are of great use in systems that use the openEHR >> Framework and allow use of operability constraints out of the box. >> What about other vendor systems? Well, Ocean tools are being used to >> produce inputs for vendors which are formal specifications of data to >> be stored and communicated. The ability to reuse these artefacts for >> many purposes - queries, transformations, display and data entry >> provides another metric that is of use. >> >> We will need some large systems built on openEHR and traditional >> approaches to compare in the future. For the moment, just having >> clinical specifications that are computable is the main influence on >> choosing openEHR - or starting from scratch as new vendors see the >> benefits (or not). >> >> Cheers, Sam >> >> >> >> Koray Atalag wrote: >>> Hi, >>> >>> I want to learn how we can formally/objectively prove that Archetype >>> based dual level development formalism alleviates problems of >>> interoperability and maintainability. I was wondering if someone did or >>> know of any such study which applies formal validation methods? >>> >>> Best regards, >>> >>> Koray Atalag, MD, Ph.D. >>> >>> _______________________________________________ >>> openEHR-technical mailing list >>> openEHR-technical at openehr.org >>> http://lists.chime.ucl.ac.uk/mailman/listinfo/openehr-technical >>> >>> >>> >> >> -- >> <OceanC_small.png> Dr Sam Heard >> Chief Executive Officer >> Ocean Informatics >> >> Director, openEHR Foundation >> Senior Visiting Research Fellow, University College London >> Aus: +61 4 1783 8808 >> UK: +44 77 9871 0980 >> _______________________________________________ >> openEHR-technical mailing list >> openEHR-technical at openehr.org <mailto:openEHR-technical at openehr.org> >> http://lists.chime.ucl.ac.uk/mailman/listinfo/openehr-technical > > > > -- <private> -- > Gerard Freriks, MD > Huigsloterdijk 378 > 2158 LR Buitenkaag > The Netherlands > > T: +31 252544896 > M: +31 620347088 > E: gfrer at luna.nl <mailto:gfrer at luna.nl> > > > Those who would give up essential Liberty, to purchase a little temporary > Safety, deserve neither Liberty nor Safety. Benjamin Franklin 11 Nov 1755 > > > > > > ------------------------------------------------------------------------ > > _______________________________________________ > openEHR-technical mailing list > openEHR-technical at openehr.org > http://lists.chime.ucl.ac.uk/mailman/listinfo/openehr-technical >
