Hi,
This is an interesting discussion. I think we need to keep a sense of
purpose here in what we are doing. We need to understand that the complexity
of biomedicine is probably unsurpassed and the language of health
professionals is a way of dealing with this. It has historical roots which
allows people to drill down when appropriate. The paper by Werner and Barry
on malaria illustrates the difficulties. So we will find, if we look hard
enough, that there are massive imperfections in what clinicians record but
these imperfections are generally understood by those that need to know
about them.
I remember a story about a medical teacher when I was young asking a rather
impertinent student what they knew about the cause of rheumatoid arthritis.
He said "Nothing". And then he asked the student "And what do I know about
the cause?" He again said "Nothing". The teacher nodded and added "But don't
underestimate the gap between what you know about the cause of rheumatoid
arthritis and what I know".
We don't call rheumatoid arthritis idiopathic arthritis because we have
accepted the syndrome and its histological features. We know the prognosis
and outcomes in many situations. Patient's would like to know why - but we
can't tell them. Malaria is actually four diseases - two of which actually
are rather different from the other two. Pneumonia, from the perspective of
causation, is actually 100s of diseases all with a similar pathology. When I
read the paper on malaria by the ontology guys I learned a lot. I have
diagnosed and treated malaria quite a few times in my life but did not know
some features of the life cycle of the plasmodium and the features that
Werner and Barry are describing at times are not of clinical significance.
So where does ontology get in the way of good health care? I would suggest
it is when there is no 'drill down'; that complexity is presented as a flat
knowledge space. Deep knowledge in clinical practice, what is needed to
provide the best care, is not necessarily detailed knowledge - the latter is
usually the preserve of bioscientists and clinicians researching an area.
They might come back to us with more detail that alters the knowledge
required to provide the best care. It is then that deep knowledge shifts.
More detailed knowledge does not necessary lead to more complex deep
knowledge. Asthma is a good example. Treatment used to be a nightmare but as
we have learned more it is really quite simple to manage.
So I just want to challenge the approach of linking to ontologies. I would
like to propose a simplification. If we take the archetypes as the purest
expression available of what clinicians want (or are able) to record then we
have something. We can organise and classify these in future to make them
very available. CKM has started that process and it will get more
sophisticated.
The task then for term_bindings is to link points in archetypes to
terminology so that other people can understand from that perspective what
we are talking about. I would argue that there are two approaches. First is
to find a term in a terminology that says exactly what the archetype is
recording. The second approach is to find the observable entity that is
being recorded.
It becomes absurd at one level to think about the things that you might
describe:
- the notion of the thing that might be observed (blood CO2 level)
- the procedure for measuring it (which might be complex) and everything
about that
- the recording of the value of the thing that has been observed and any
confounding factors
- the actual value of the thing observed.
The archetype actually records many of these things as well as the value. A
pure ontology for such a thing will get massively complex. Do we have the
procedure for measuring the confounding factors, the recording of the
procedures for measuring them, the actual value of these etc. If we are
measuring the blood gas there may be may features of the measuring process
that we want to record - do we have observable entities for all of these,
procedures for measuring them and recording and values.
I hope you can see where we are going here. We have to stay anchored in what
is useful and effective clinical practice. The fractal nature of this is
becoming clear and we will see just how fractal things get when we start
recording genetic features of cancers (and people).
I think we should start by working purely with term_bindings for the
observable entity that is expressed in the archetype - as a whole and then
for each entry in the data section of the observation if that is helpful.
I find this a very fruitful area of enquiry and I do not want to stifle it
at all - just to point out that what might appear imperfections often are
important kludges that are shared widely and work in real practice.
Cheers, Sam
> -Original Message-
> From: openehr-technical-bounces at chime.ucl.ac.uk [mailto:openehr-
> technical-bounces at chime.ucl.ac.uk] On Behalf Of Fabrice Camo
