# Archetypes and terminologies. **Category:** [Clinical (archive)](https://discourse.openehr.org/c/clinical-archive/153) **Created:** 2008-08-14 09:07 UTC **Views:** 2 **Replies:** 5 **URL:** https://discourse.openehr.org/t/archetypes-and-terminologies/14809 --- ## Post #1 by @Andersson_Richard What happens if an end\-user wants to create a template and use a terminology as often as possible, and the archetypes are constrained to be free text instead of terminology? Shouldn't all archetypes enable the use of a terminology? For example: In the well\-known observation\.blood\_pressure the person state position is constrained to internal codes and one of them is "sitting"\. What if the template creator wants to use the SNOMED term 33586001 instead of an internal code? Richard Andersson University Hospital of Lund Sweden --- ## Post #2 by @thomas.beale Richard, Someone clnical will probably explain in more detail, but the basics are as follows: - if a DV_TEXT is specfied at a certain point in an archetype, a DV_CODED_TEXT is always substitutable at runtime; the contents of this DV_CODED_TEXT can be specified in the template if require, and in ADL 1.5 (forthcoming this year), in archetypes as well - a dynamic subset can be specified at the same kind of point in an archetype - this is shown with an acNNNN code, and binds to e.g. a specific Snomed subset. This is done in the 'constraint bindings' part of the archetype ontology section. - any use of a fixed archetype term (i..e atNNNN code) can always be bound individually to external terms, e.g. the example you give below. This is done in the 'term bindings' part of the archetype ontology section. A give at-code can be bound to terms in more than one terminology. - thomas beale Andersson Richard wrote: [details="(attachments)"] ![OceanC\_small.png|74x72](upload://5I367QG2SMJUp18Pt3jF6yz13Ey.png) [/details] --- ## Post #3 by @erik.sundvall Hi\! I believe all archetypes I have seen have fields constrained to "free or coded text" \(not only "free text"\) giving you the option for either choice at template creation time\. In the AM \(and thus also in ADL\) the "free or coded text" means the class DV\_TEXT which is a superclass of DV\_CODED\_TEXT, see chapter 5 of http://www.openehr.org/svn/specification/TAGS/Release-1.0.1/publishing/architecture/rm/data_types_im.pdf If I understand the model correctly it is then impossible to constrain any field to be only "free text" since DV\_CODED\_TEXT is always allowed where DV\_TEXT is allowed\. Best regards, Erik Sundvall erisu@imt\.liu\.se http://www.imt.liu.se/~erisu/ Tel: \+46\-13\-227579 P\.s\. Just to minimize confusion DV\_CODED\_TEXT is used when you want to specify a code from a system like SNOMED CT or ICD\. --- ## Post #4 by @heather.leslie Hi Richard, the default setting when adding a Text datatype in an archetype is 'Free text or coding'\. This can be further constrained as an internal codeset or bound to terminology within the archetype, as required\. I totally agree that in a majority of cases the 'Free text or coded' option is ideal\. After all the archetype is 'a maximal data set for a UNIVERSAL USE CASE' \- this gives us the most flexibility ranging from free text entry through to coding at runtime\. If left as 'free text or coded' then the element can be further constrained by binding to a terminology subset in the template \- one that is relevant and meaningful for the use case\. This is in increasingly common use and a key consideration in active modelling at present\. The internal codes are useful where you need more structure than free text, but a terminology subset cannot meet the needs for structured data capture, and this is the situation in the BP archetype\. The large number of clinicians who have looked at the BP archetype over the years have not had any problem with the internal code list of positions \- so lying, sitting, standing and reclining seem to make clinical sense to them\. Now I am not a Snomed expert at all, but when browsing for body position within Snomed there does not seem to be a consistent way to represent these 4 terms\. Yes, by all means bind the SCT term 33586001 to the sitting value \(and this is possible in the Archetype Editor via the Terminology tab\)\. And you may find acceptable ones for standing and lying, although not so clear to me\. But reclining appears to be absent on my searches, and this is probably the default value that is desired for most BP readings in an inpatient hospital situation\. So internal codes are providing structure where structure is required in data capture/display but where the terminology can't provide a meaningful subset\. Or it may be a specific list of values for a particular use case where terminology is not really necessary or helpful for querying, for example whether a menstrual period is 'lighter/same/heavier than normal'\. In any case, any one, some, or all of the internal codes can be bound to any terminology code \(or even multiple terminologies\), if desired\. There will not be many situations where a text datatype will be bound to a terminology subset in an archetype as this commits every user in every use case to using a terminology subset\. Many will not have access to the terminology, it may not be geographically relevant etc etc \- there will be many situations where this is not ideal, especially the more 'international', or potentially shareable\. the archetype is\. So, in practice:     \* Most terminology subsets \(which represent valuesets\) will be bound       within templates to a text datatype that was represented as 'free       text or coded' in the archetype\. This gives the required       flexibility for each clinical use case\.     \* On the other hand, it is likely that there will be many examples       where terminology codes will be 'one to one' bound within the       archetype to root nodes, data elements or internal code values,       where common agreement for that code can be found amongst the experts\. Regards Heather Andersson Richard wrote: --- ## Post #5 by @thomas.beale Erik Sundvall wrote: > Hi\! > > I believe all archetypes I have seen have fields constrained to "free > or coded text" \(not only "free text"\) giving you the option for either > choice at template creation time\. > > In the AM \(and thus also in ADL\) the "free or coded text" means the > class DV\_TEXT which is a superclass of DV\_CODED\_TEXT, see chapter 5 of > http://www.openehr.org/svn/specification/TAGS/Release-1.0.1/publishing/architecture/rm/data_types_im.pdf > > If I understand the model correctly it is then impossible to constrain > any field to be only "free text" since DV\_CODED\_TEXT is always allowed > where DV\_TEXT is allowed\. > this will change with ADL 1\.5, which adds a mechanism to remove subtypes\. The following syntax is proposed\. value matches \{     DV\_TEXT matches \{ \.\.\. \}     DV\_CODED\_TEXT occurrences matches \{0\} \} \- thomas beale --- ## Post #6 by @Andersson_Richard Hi everybody, I want to thank you all for making it clear for me what "Free text OR CODED" means\. Now it makes sense to me and I see that the binding to a terminology is possible and optional in the template\-making phase\. Regards Richard --- **Canonical:** https://discourse.openehr.org/t/archetypes-and-terminologies/14809 **Original content:** https://discourse.openehr.org/t/archetypes-and-terminologies/14809