On Mon, 10 Feb 2003 [EMAIL PROTECTED] wrote: ... > Archetypes are great to define very concise medical concepts like labtests > and bloodpressure, but how to handle a description of a stomach ulcer done > during an endoscopic examination? Should all this be structured beforehand?
Helma, Obviously, it is not possible or desirable to fully pre-structure a description of a patient. That is basically the task that must be accomplished by the medical records system. On the other hand, it is helpful to structure the information - having some meta-data helps someone else understand what you are trying to communicate. You see examples of metadata in headings, sub-headings, etc - archetypes and OIO forms are just more complicated versions of the same. So, I think a compromise is to use meta-data/structure but allow flexibility in composition: a description of the patient consists of variable number and kinds of structured-data-elements. For example, a patient would be described by any number of OIO forms that have been completed by the patient's physicians. Does this make sense? > Say you include a data structure for a description of the tissue > around the ulcer, would you require this to be optional or obligatory > even if it's not always necessary to be filled in. Obviously, you cannot make every single data-element obligatory. After all, some patients don't even have an ulcer. :-) Thus, everything is optional. However, certain data may be conditionally obligatory - for example, if you are completing a certain "form" that describes a patient's ulcer, you may have to specify where the ulcer is. > And how would you store the recordings of this ulcer? In an anatomic > hierarchy? Or in the context of the endoscopic examination? The OIO system stores these recording as data-collected-through-a-form :-). > How to model an endoscopic examination, since it can not only be done > for ulcers but also for numerous other purposes? Thus, how an "endoscopic exam" is modeled must depend on its "purpose". The OIO system makes no assumptions about the "purpose" - and I believe it is a common mistake to artificially mandate a "purpose" in the "knowledge creation process" at that early stage. Afterall, often data and information have much different uses/purposes long after they are collected! I believe that in the haste by "knowledge engineers" to model "knowledge", they are ignoring the necessary steps that data must traverse to become knowledge. > Archetypes are said to enhance data exchange, but how necessary is > this? Metadata constructs such as GEHR/OpenEHR archetypes and OIO forms are not necessary *at all* for data exchange. The hope is that they will make data exchange easier! > I could think of data exchange between specialists and GPs, but > GPs would probably have no archetypes for endoscopic examination and > their "ulcer" archetype would be very different. How to handle this? There must be a "translator" or mediator that goes between the two. What Adrian Midgley says about inheritance etc makes sense if and only if a universal set of controlled vocabulary/metadata are fully accepted and used. I believe this approach has been tried many times and will not work. > You could send over the archetypes as well, but what to do then? 1) You can view the patient records sent over by the specialist. Although the archetype is foreign to you, you may still know enough about ulcers to understand the specialist's desription. 2) You can either construct or download a mediator that can translate information from the specialist into your own "format" (archetype/form). Does this make sense? > Storing the specialist archetypes would not make sense since the GP > doesn't need them for his day-to-day work and if he did store them, > how would the specialist "ulcer" archetype interfere with his own > archetype? In the OIO system, the GP can keep the specialist form around if he/she wishes to continue to view the information in its original form. If the GP keeps the specialist's form, this form will not change or interfere with the GP's own ulcer form. They are two distinct and separate forms - although information can move between them through the mediator / translator. Please let me know if you like a more detailed explanation of this process. > Furthermore: I'd use archetypes as a template for objects resulting in > objects that hold all necessary context information. In my opinion the > archetype is then superfluous since all context related information is also > available in the object. This is true. But, in order to create the information object (which as you said, contains both the data and the metadata), you need the metadata structure - unless you prefer to create the metadata de novo each time you create the information object. In fact, that's what happens in paper-based systems when you begin to write on a piece of blank paper: You are creating metadata and data from nothing on the paper. Using an OIO form is exactly like starting with a printed form (which provides meta-data) instead of a blank piece of paper. Does this make things clearer? > Another point: archetypes contain validation rules. But where does "data > validation" end and "decision support" begin? It's obvious to validate > "diastolic" vs. "systolic" values in a bloodpressure (assuming you store > both values in one concept), but what if you want to use the body mass index > to validate weight and/or length? I can understand your observation that the two (validation and decision support) are similar in certain ways. In my mind, I think decision support involves processing of information that have already been collected and stored. On the other hand, validation involves tools that facilitates collecting the "correct" information. > How do you refer to information that is constructed with another > archetype? Great question! This is exactly what I have been working on over the past few months. I would love to discuss some of the possibilities that I have come up with if you are interested. Since this will be a lengthy reply, I suggest that we move this discussion over to the open-outcomes-general mailing list. Is that acceptable to you? > Please don't think I'm against archetypes, but the idea is still not clear > to me. I hope my reply is somewhat helpful. Please feel free to ask more questions. Best regards, Andrew --- Andrew P. Ho, M.D. OIO: Open Infrastructure for Outcomes www.TxOutcome.Org (Hosting OIO Library #1 and OSHCA Mirror #1)
