On 28/09/2011 09:05, Ian McNicoll wrote:
>> ? Should the values simply be described, or actually assigned, in
>> the archetype (via the data type itself) and how much of this should be left
>> in the application GUI/workflow/logic?
>>
> [IAN] Wel,, yes. But surely the point of archetypes is to formally
> document as much of this knowledge as possible, rather than leaving it
> to application logic. I have managed to workaround the current
> restriction for the Waterlow Scale archetype but it is pretty
> counter-intuitive. The strength of the RM is that it should be rich
> enough to capture these sort of clinical ideas in a way that is clear
> ot both clinicians and developers. The idea of a termset mapped to
> numeric values is, I thikn, valid. The only issue is whether it makes
> sense to adapt the DV_ORDINAL for these non-unique uses-cases, or
> whether a new datatype is required
>
Ruminating on the discussion so far, it seems to me that we do need to
do this properly. What use are openEHR archetypes if they don't cope
with common medical things? A new data type seems to make sense - a kind
of DV_CODED_TEXT containing also a score_value attribute. Maybe we can
call this DV_CODED_VALUE (other possibilities: DV_CODED_RATING,
DV_CODED_SCORE)? The properties would be different from DV_ORDINAL: with
DV_CODED_VALUE, each possible value in a series must have a distinct
code and meaning, but may have any numeric value associated with it,
allowing multiple such DVs to have the same value. If we wanted to make
it quite score oriented - which seems like a good idea to me, we might
use the name DV_CODED_SCORE_VALUE, and include in it a reference to the
score, in the form of a DV_CODED_TEXT.
Thus:
class DV_CODED_SCORE_VALUE
inherit
DV_CODED_TEXT
score_value: Real
score_reference: DV_CODED_TEXT
end
This requires more thinking by those who know the problem better than I
do, but it is easy to test any model like this by adding to an
experimental variant of one of the BMM-schemas used in the ADL
Workbench. Test archetypes can then be written to see what it is like.
- thomas
