linking terminologies and conditional items in a template.


I’m discovering OpenEHR and I have some questions :

  1. In the Template designer ( how we can import and use code systems like SNOMED CT ?

  2. I have created an archetype “handedness” and I made it as coded text for two values : right hand, and left hand. how can I choose and link snomed ct codes for these three items ? handedness, right hand and left hand ? (within the archetype)

  3. how to create conditional questions in a template ? I have created a coded text archetype : Recent weight loss, with the answers, yes and no. I want to have a data type Amount of weight loss if the answer to recent weight loss is yes. how should I manage it ?

Many thanks for your help !

Hi Mobin,

There are several options

  1. Leave the valuesets for handedness unconstrained i.e no valueset of left and right, and then add the valueset at template level, either as a fixed list of SNOMED-CT terms , or as a link to a FHIR Valueset.

  2. Add the internal valueset as you have done so far ‘right hand, left hand’ but then add term-bindings to specify the correct SNOMED-CT terms to be used both for the values right hand, left hand and for the node name ‘Handedness’.

You can add term bindings via the Terminology tab in Archetype Designer. You need to add the terminology first, then select each internal term and bind it to a SNOMED term.

It is important to note that Term-bindings are only ‘suggestions’ in the archetype, they do no automatically appear in the patient record when a composition is saved.

To save additional terms alongside the internal code, the developers need to add them into the ‘mappings’ structure in the DV_CODED_TEXT datatype.

Ideally we would have a way of defining this behaviour in the template i.e ‘please add these mappings to this datapoint’ but this does not exist right now. There is a long recent thread in the topic here.

For Conditional logic, the simple answer is that you can’t do this in templates. Many years ago we tried to do something like this but it became very messy and such rules are left to applications or form-build layers above templates like Better Studio, but so far these are out of scope of ‘pure’ openEHR. I suspect at some point a minimal form logic layer will appear, perhaps close to the FHIR Questionnaire Response idea but no-one is working on a common standard for that right now AFAIK.


Would you be willing to add this nice summary to confluence ? @CPB_Board let me know if you feel this confluence shouldn’t be edited by non-members.

I’d rather do it properly with some examples, but yes, no problem to share, either on Confluence or elsewhere.

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I’m technically not on the board as such, but personally I think anyone willing and capable to spend time adding documentation to the wiki should be able to do so.