# Specialising value set items?

**URL:** <https://discourse.openehr.org/t/specialising-value-set-items/970>\
**Category:** Clinical\
**Tags:** adl, archetype, snomed-ct\
**Created:** [10 September 2020 11:00 UTC](https://discourse.openehr.org/t/specialising-value-set-items/970 "2020-09-10T11:00:24Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![siljelb](https://discourse.openehr.org/user_avatar/discourse.openehr.org/siljelb/32/12_2.png) [@siljelb](https://discourse.openehr.org/u/siljelb)\
**Post date:** [10 September 2020 11:00 UTC](https://discourse.openehr.org/t/specialising-value-set-items/970/1 "2020-09-10T11:00:24Z")

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I’m working on a specialisation of an archetype. The parent archetype has a DV\_CODED\_TEXT element with internal codes, with SNOMED CT codes bound to each internal code. The specialisation slightly narrows down the definition of each internal code, which I would like to reflect by specialising each code in terms of textual description and which SNOMED CT code is used. AD isn’t letting me do this. Is this a tooling issue or a specifications issue?

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**Author:** ![thomas.beale](https://discourse.openehr.org/user_avatar/discourse.openehr.org/thomas.beale/32/35_2.png) [@thomas.beale](https://discourse.openehr.org/u/thomas.beale)\
**Post date:** [10 September 2020 12:01 UTC](https://discourse.openehr.org/t/specialising-value-set-items/970/2 "2020-09-10T12:01:13Z")

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> [@siljelb](#):
>
> The specialisation slightly narrows down the definition of each internal code

Hi Silje,

Not sure what this bit means - the meaning of an already-defined code in an archetype cannot be redefined, just like a code in SNOMED or ICD. Or do you mean that the codes have been specialised, e.g. at12 → at12.1 etc? If so, the latter are distinct, semantically specialised codes, in the same sense that the code for ‘lymphoma’ is a specialised child of ‘cancer’ (or malignant neoplasm, or whatever it is), and you should be able to define them normally.

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**Author:** ![siljelb](https://discourse.openehr.org/user_avatar/discourse.openehr.org/siljelb/32/12_2.png) [@siljelb](https://discourse.openehr.org/u/siljelb)\
**Post date:** [10 September 2020 12:23 UTC](https://discourse.openehr.org/t/specialising-value-set-items/970/3 "2020-09-10T12:23:47Z")

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> [@thomas.beale](#):
>
> Or do you mean that the codes have been specialised, e.g. at12 → at12.1 etc?

I mean that this is what I’m trying to do, but the tool won’t let me. For example, I want to specialise the finding code “Heart beat irregular” to “Pulse irregular”.

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**Author:** ![thomas.beale](https://discourse.openehr.org/user_avatar/discourse.openehr.org/thomas.beale/32/35_2.png) [@thomas.beale](https://discourse.openehr.org/u/thomas.beale)\
**Post date:** [10 September 2020 12:30 UTC](https://discourse.openehr.org/t/specialising-value-set-items/970/4 "2020-09-10T12:30:27Z")

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Aha! So it’s a tool problem… [this is the part of the spec](https://specifications.openehr.org/releases/AM/latest/ADL2.html#_object_redefinition) that talks about redefining codes - but it might depend on you having created the relevant specialised nodes first? I guess you did that?

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**Author:** ![siljelb](https://discourse.openehr.org/user_avatar/discourse.openehr.org/siljelb/32/12_2.png) [@siljelb](https://discourse.openehr.org/u/siljelb)\
**Post date:** [10 September 2020 13:08 UTC](https://discourse.openehr.org/t/specialising-value-set-items/970/5 "2020-09-10T13:08:49Z")

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> [@thomas.beale](#):
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> but it might depend on you having created the relevant specialised nodes first?

I’m unable to find a way to explicitly specialise each code, only the data elements. Sounds like a tooling issue then?