Hi, When you build an information system, you have to create a solid structure in order to have people fill it with datas, just like a building is made of concrete, or steel or wood, but anyway stands up alone.
Most information systems have a structure made of a database, openEHR is innovative with the far more flexible Archetypes ; what about ontologies ? To explain it, we can keep on with the model of a solid structure that allows the system to "stand up", but instead of the building example, we will shift to a note-book example : With a "Database structure", the note-book would already be fully pre-printed with a given set of forms. If they don't fit your needs, you still have to cope with. With an "Archetype structure", you are presented with a blank note book and a set of stamps to create the forms you want where you want (and you can get new stamps if you need it). It is the Archetype "2 levels" model : the information that makes the system stand up is in the stamps - it can make a form you can fill on the note-book. With an ontology, things are more subtle since whats make the system stand up is the couple "word + semantic". To keep on with the note-book example, I would say that you no longer need forms, you simply have to use the terms of the ontology and make sentences with them. It works because what you "write" has a meaning for the system. Of course, you can also use stamps sometimes (Archetypes) to speed the writing and ease the reading (repetability), but the semantic is in the words themselves and not in the form (I mean you even could forget the Archetype afterward - of course it won't be smart, but it would still work). I don't know if this model helps to understand the genuine concepts behind ; however, it is pretty close from the way we build Odyssee. Best regards, Philippe >Christopher Feahr wrote: > >>. but my understanding was the the SNOMED people had >>already modeled complaints, signs/symproms, diagnosis, treatment plans, >>prognosis, outcomes... the whole 9 yards. If that is true (seems too >>good to be true!) then it may only require a (simple??) mapping of >>SNOMED CT to a collection of EHR Archetypes. >this is a bit question. The key thing to remember is that: > >- terminologies/ontologies (attempt to) model reality, e.g. their model of >symptoms related to tropical parasite infections will/could be a detailed >semantic net of nodes describing in great detail the symptoms at every >point of e.g. plasmodium lifecycle during malaria infection - textbook >stuff in other words. > >- but the doctor in a hospital is interested in recording observations >about the patient, ordering tests, making decisions, following progres and >so on. The information he/she wants to record and read is to do with the >observation and care process, not with the scientific description of the >life history of plasmodium. This is the area of archetypes and templates - >providing highly configurable models of this information and processes, >during the clinical care path. > >- terminologies are necessary as a knowledge base during the use of >archeytpes - they provide names of things of course, but more importantly, >semantic networks support inferencing. So one can imagine a doctor >recording symptoms and signs in their info system, and thinking that so >far, it could be malaria or some other fever-inducing infection... if they >have detailed enough observations, it may be that the ontology can provide >some guesses as to what the patient has. > >So - we have two kinds of models here: terminology/ontology is about >modelling the real world, and facts we have learned and appear to be >dependable; archetypes and templates are about modelling patterns of >information *in use*, and they depend on ontology for meaning of items >they mention. Archetypes provide for a lot of optionality, whereas this is >not part of ontology (except ontologies modelling decision making >processes themselves perhaps). > >- 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
