Paul wrote:
>
> A wise quote that I heard when I started medical informatics training
> was "a lot of what we practice today is wrong." I'm a pediatrician,
> and I can attest to this... and because of the constant evolution in
> best practices, there's always a "scattergram" of practice styles vs.
> best practices. That is, the urinalysis today, might not be the
> urinalysis of tomorrow. Some might continue to use the old urinalysis
> for a number of various reasons, and some of those reasons might be
> correct. Therefore, there arise various flavors and colors of a single
> "archetype" that I think I understand represent models of how certain
> care is delivered. These coexisting vagaries and various evolutions
> of medical concepts unfortunately I think are a necessary reality of
> health information system design.
>
Yes, things change all the time. Archetypes are designed flexibly as
'maximal data sets' that collect related data items together. See e.g.
the BP measurement archetype:
http://svn.openehr.org/knowledge/archetypes/dev/html/en/openEHR-EHR-OBSERVATION.blood_pressure.v1.html.
Within a template only a couple of items might actually be used, but no
matter how many are, one can be sure they respect the archetype
structure. This means as a consequence that the data are all queryable
in a standard way, using the extracted archetype paths (I have shown the
human readable versions):
/data[history]/events[baseline reading]/data[blood
pressure]/items[systolic]/value DV_QUANTITY
/data[history]/events[baseline reading]/data[blood
pressure]/items[diastolic]/value DV_QUANTITY
/data[history]/events[baseline reading]/data[blood
pressure]/items[Comment]/value DV_TEXT
/data[history]/events[baseline reading]/data[blood pressure]/items[mean
arterial pressure]/value DV_QUANTITY
/data[history]/events[baseline reading]/data[blood pressure]/items[pulse
pressure]/value DV_QUANTITY
/data[history]/events[baseline reading]/offset/value DURATION
/data[history]/events[baseline reading]/state[state
structure]/items[Position]/value/defining_code CODE_PHRASE
/data[history]/events[baseline reading]/state[state
structure]/items[Exertion level]/value DV_QUANTITY
/data[history]/events[baseline reading]/state[state
structure]/items[Exercise]/value/defining_code CODE_PHRASE
/data[history]/events[baseline reading]/state[state
structure]/items[Tilt]/value DV_QUANTITY
/data[history]/events[any event]/data[blood
pressure]/items[systolic]/value DV_QUANTITY
/data[history]/events[any event]/data[blood
pressure]/items[diastolic]/value DV_QUANTITY
/data[history]/events[any event]/data[blood
pressure]/items[Comment]/value DV_TEXT
/data[history]/events[any event]/data[blood pressure]/items[mean
arterial pressure]/value DV_QUANTITY
/data[history]/events[any event]/data[blood pressure]/items[pulse
pressure]/value DV_QUANTITY
/data[history]/events[any event]/state[state
structure]/items[Position]/value/defining_code CODE_PHRASE
/data[history]/events[any event]/state[state structure]/items[Exertion
level]/value DV_QUANTITY
/data[history]/events[any event]/state[state
structure]/items[Exercise]/value/defining_code CODE_PHRASE
/data[history]/events[any event]/state[state
structure]/items[Tilt]/value DV_QUANTITY
.. etc ..
/protocol[list structure]/items[Cuff size]/value/defining_code CODE_PHRASE
/protocol[list structure]/items[Location of
measurement]/value/defining_code CODE_PHRASE
This standardised querying is one of the things that is most powerful
about archetypes - no matter what template the data were captured in, it
is the original archetype that determines the query paths. Actual
queries look as follows:
SELECT
o/data[at0001]/events[at0002]/time,
o/data[at0001]/events[at0002]/data[at0003]/items[at0013.1]/value --
Total cholesterol
FROM
[EMAIL PROTECTED] CONTAINS
Composition c[openEHR-EHR-COMPOSITION.encounter.v1] CONTAINS
Observation o[openEHR-EHR-OBSERVATION.laboratory-lipids.v1]
These archetypes do evolve; as long as they obey the basic terminology
principle of not-redefining the meaning of existing items, everything
works automatically.
- thomas beale
