"Mattias Forss" <mattias.forss at gmail.com> wrote: Hello Mattias,
these are exactly the questions, issues I have been working on for 3 years now. All I can specify in the HL7 v3 Care Provion Domain model, that is basically why I apply this method for the time being, waiting for a better tool to do this. Below specific answers after each question. >Hi, > >I'm currently working in a group that has been evaluating archetypes and >they found out that there in archetypes may be needed to add external nodes >from other archetypes instead of only adding complete archetypes as slots. I agree, in the care provision we therefore have included the organizer class that allows you to start with atomic items, link them via an organiser code to a higher level item (e.g. blood pressure is part of vital signs, mobility is part of activities of daily living, potasium is part of electrolytes etc.). I work bottom up because of another question of you below. This is possible in ADL I believe / am told, but have not seen operationalised yet. However the template specifier does this, but I am not sure how the formal links work. In organiser we can code the higher level rubrics. >Does the current ADL specification allow that external parts from other >archetypes can be included? I think the openEHR templates allow to cut off >parts in a slot, but I'm not sure if they can exclude everything except a >single item. > We break down such care information models in two parts if there are use cases where only a part is used. So we make 2 slots instead of one. >The group also found out that there is a need to deduct certain answers >depending on previously answered questions. For example if we previously >answered that the blood pressure was above 160, then another question about >hypertension should be answered automatically. Is this possible to do in >archetypes? > We can relate HL7 obs classes to each other, including if a value of Obs 1 > 160, then Obs gets default hypertension. However, there is no agreed formalism in HL7 v3 to do this. Arden syntax an d Gello are often named in this area, but I have no examples. I just use plain english for the time being. >Another issue is about computation. For example we could want a quantifiable >magnitude to be the result of two previously entered values. Is this >possible to do in archetypes? We apply this a lot in the HL v3 care information models. Basically most scales have a kind of sum up feature of say 10 observations (Barthel) each gets a numeric score and obs 11 is for the total score. In the method section we define: total score, but again, there is no formalism used, just plain English. Similarly this would work with basic calculations such as average scores, or the formula for the body mass index etc. Perhaps in the declaration section or the >invariant section? I've seen that these sections should contain some kind of >first-order predicate logic, but I'm not sure of the scope and >limitations/possibilities of these ADL sections. Also, the declaration >section is actually not even described in the ADL 1.4 document, it is only >shown in an example overview figure. > It is perfectly possible to express your rules in predicate logic and if only it would be included as a comment text part, it will be clear that the system needs to be able to do such operations on the variables. >Another feature is value reporting, which should work when we use several >archetypes in an openEHR template. For example if some question was answered >in one archetype, then another archetype that has the same question should >get the value reported from the previous archetype. Is this possible? I >guess this has to do with external references as I mentioned in my first >question. If the first observation is coded appropriately (tracable and identifyable) then the second one could refer to this codes variable. It would work so that the variable in question and addressed from 2 archetypes, would have the same code and both archetypes should allow entering the value and presenting the value. But again, I would prefer a bottom up approach. Given that this variable is used in 2 archetypes for me would imply it can be better an atomic archetype in itself, where the other more molecular ones include this atomic archetype. This goes back to your earlier question: the bottom up approach which we currently apply in the Care Provision modelling works such that you can do what you ask for here. >We would also like to ask if there is a way of specifying validity for >questions depending on previously answered questions. E.g. if a certain >answer was given from a multiple alternative question (coded_text), then and >only then, some other group of questions will be valid. Is this possible to >do in archetypes? Perhaps it's possible with invariants? > I understand your question, we have similar use cases, e.g. for questions related to being eligible for types of care or treatment or facilities. We currently work in the care information models (www.zorginformatiemodel.nl) in which we summarize the clinical background of the content of the 'archetype', list the variables, explain the mathematical, logical or decision style requirements as you have asked about above, then specify the HL7 artifact, then specify the technical implementation things (e.g. datatype, code, cardinality etc. ). The latter can easily be included in ADL. >Finally is there a way of specifying the relevance of answers in archetypes. >Say for example that if some laboratory results are too old, could an >archetype contain some restrictions that make it illegal to answer certain >questions because the material that the answers are based upon is too old? >I'm not sure if this is related to DSS or something else. In the HL7 v3 Care Provision Care Planning specification this can be done: each care information model can be in definition mood. This is the guideline representation. It is possible to specify the time limits e.g. by defining the IVL of the effective time of an event of an observation. > >Regards, > >Mattias, via the Link?ping Team. > Hope this helps, William _______________________________________________ openEHR-technical mailing list openEHR-technical at openehr.org http://www.chime.ucl.ac.uk/mailman/listinfo/openehr-technical
