[Dcm] terminfo meeting room requirements/Planning for Phoenix

Clinical (archive)
21

Tom,

Thanks for these definitions and examples, they’re very helpful.

observation: it is a procedure, taught to professionals to be repeatable

and reliable, without which they would need some other observational

method to establish problems in the liver. The fact that it is in use

shows that it is an adequate and useful observational method, and

generates results that are statistically acceptable.

  • But ‘Systolic: High’ isn’t this an Evaluation with implicit or

explicit classification criteria?

The Evaluation is an expression of a professional opinion.

To document Blood pressure as low or high is this no longer an

observation but an Evaluation or both?

Here we get into linguistic challenges. If the understanding of ‘high’

is derived from the following:

low: < 90 mmHg

normal: 90mmHg - 140mmHg

high: > 140 mmHg

then assuming there is an instrument available to generate the value

‘high’ it is an observation (at a very coarse precision), since it is a

repeatable and objective. If the ‘instrument’ is in fact a human being

reading from a normal digital or analog device, then it may questionable

as to whether the more precise measurement should not be recorded.

If however, the word ‘high’ is being used by the clinician to mean 'this

patient is hypertensive’, i.e. the BP is too high, then it is an

evaluation. And that’s why words like ‘hypertensive’ exist. In this

second case, the band of values that correspond to ‘high’ may vary with

the patient, e.g. sex, weight, age, pregnancy, diabetic, or just plain

personal variation. So the use of the word ‘high’ in this circumstance

indicates an assessment by the clinician that the observed blood

pressure is higher than normal, i.e. too high for the given patient.

Question is, is a (part of) the Barthel index score: (needs) little help (to be mobile) (see my response to Heathers mail as well) an observation or an interpretation/ evaluation. I would say it’s an evaluation.

Cheers,

Stef

22

Gerard Freriks wrote:

Observation: Systolic pressure: No, Yes

Observation: Systolic pressure: 0, +, ++, +++, ++++, +++++

I want to meet the GP who measures BP like this :wink:

But he will use the frase:
High Blood pressure,
Low Blood sugar.

And +++ and - are just equivalents/synonyms of High and Low.

Are all examples of the same nature?

  • A measurement by a device is it the same as an observation by a human?

yes: just a question of the statistical accuracy band.

  • A liver that is palpable by a human is this an observation or an

subjective interpretation and therefor an Evaluation?

So far any documentation about the patient system as a whole is an

observation. I think this is correct.

observation: it is a procedure, taught to professionals to be repeatable
and reliable, without which they would need some other observational
method to establish problems in the liver. The fact that it is in use
shows that it is an adequate and useful observational method, and
generates results that are statistically acceptable.

So we agree.

  • But ‘Systolic: High’ isn’t this an Evaluation with implicit or

explicit classification criteria?

The Evaluation is an expression of a professional opinion.

To document Blood pressure as low or high is this no longer an

observation but an Evaluation or both?

Here we get into linguistic challenges. If the understanding of ‘high’
is derived from the following:

low: < 90 mmHg
normal: 90mmHg - 140mmHg
high: > 140 mmHg

then assuming there is an instrument available to generate the value
‘high’ it is an observation (at a very coarse precision), since it is a
repeatable and objective. If the ‘instrument’ is in fact a human being
reading from a normal digital or analog device, then it may questionable
as to whether the more precise measurement should not be recorded.

If however, the word ‘high’ is being used by the clinician to mean ‘this
patient is hypertensive’, i.e. the BP is too high, then it is an
evaluation. And that’s why words like ‘hypertensive’ exist. In this
second case, the band of values that correspond to ‘high’ may vary with
the patient, e.g. sex, weight, age, pregnancy, diabetic, or just plain
personal variation. So the use of the word ‘high’ in this circumstance
indicates an assessment by the clinician that the observed blood
pressure is higher than normal, i.e. too high for the given patient.

We agree, again.

  • When we document Systolic pressure: +++,

don’t we need to have in the cluster archetype (pattern) a facility to

express what we mean by +++ or high in order to interpret correctly

the information?

In other words is an ordinal at the archetype level not a pattern in

itself?

A pattern that defines a semi-quantitative observation or evaluation?

I think we only need to do such things if a physician is realistically
going to use them. I would have thought that ‘high’ would never be used
as a primary observation, but only in the evaluation sense, and I did
not know that +++ was used at all for BP.

What I’m hinting at is the need for patterns that express:

  • quantitative measurements: systolic=120
  • semi quantitative measurements also called ‘ordinals’: systolic=high or +++
  • qualitative measurements. Systolic=present

When I talk about patterns it means sub-archetypes that can be re-used in other archetypes.
And I’m not talking about data types.

  • When there are patterns for qualitative, semi-quantitatve and

quantitative observations and evaluations,

does this mean that these cluster archetypes as patterns will be

expressed no longer as ordinal data types but a collection of

quantities and codes?

well, if we want to use ‘high’ according to the first sense I describe
above, and +++ likewise, then we would use ordinals, because the latter
supply a means of defining the bands of terms like ‘low’, ‘normal’,
‘high’ etc, but if you want to use them as diagnostic terms, then they
need to be coded and bound to things like Snomed::hypertension etc.

We have to remain ever-vigilant to the intricacies of natural language!

  • thomas beale

openEHR-clinical mailing list
openEHR-clinical@openehr.org
http://lists.chime.ucl.ac.uk/mailman/listinfo/openehr-clinical

– –
Gerard Freriks, MD
Huigsloterdijk 378
2158 LR Buitenkaag
The Netherlands

T: +31 252544896
M: +31 620347088
E: gfrer@luna.nl

Those who would give up essential Liberty, to purchase a little temporary
Safety, deserve neither Liberty nor Safety. Benjamin Franklin 11 Nov 1755

23

Stef Verlinden wrote:

Question is, is a (part of) the Barthel index score: (needs) little
help (to be mobile) (see my response to Heathers mail as well) an
observation or an interpretation/ evaluation. I would say it's an
evaluation.

*could 10 randomaly chosen occupational therapists come up with the same
answer to the question? If yes, it is an observation. What does 'a
little help' mean? What does 'mobile' mean?

- thomas

24

Hello everybody!
Just a brief introduction, as I am new to many of you: I am working at the
University of Applied Sciences Technikum Wien, Biomedical Engineering, some
teaching, some program directing. Before that I had 15 years at the general
hospital in Vienna, which is a university hospital, a lot of that designing
software for biosignal analysis research.

I am also chairing the Austrian mirror groups to CEN TC251 and ISO TC215,
and moderating the working group for "Interoperability and Standards" within
the Austrian eHealth Initiative, which provided guidelines that were used to
design the architecture of the Austrian national EHR (called ELGA, see
www.arge-elga.at, sorry german only). I am also consulting the ELGA project
in the work on harmonised medical documents (discharge information, lab and
radiology report, and medication). In that I am moderating a representative
high level group of laboratory experts, who have been assembled to decide
the medical content of laboratory reports for Austria, as an integrated part
of the work on the core applications of ELGA. I am also a founding member of
IHE Austria (www.ihe-austria.at).

In everything I have been doing for the last 5 years, I wanted to contribute
to the application of international standards in healthcare. In this time I
gradually became aware of the benefits of archetypes, and also realized the
limitations that we have to accept when we want to apply this advanced
technology into clinical practice. I believe that both sides have to move,
modify and learn, and meet somewhere in the middle. This process is visibly
going on, and I am here because I believe that you are a very relevant
meeting point. Especially after the discussions we had in Gothenburg in ISO
TC215 WG9 two weeks ago.

At this point I would like to join in, because Stef raises exactly the
question that is central to me:
"Since these agreements should have nothing to do with the RM used in
the end I wondered if this DCM platform could be a place to share out
knowlegde and experience and boost the harmonization in clinical
modelling."

They group of laboratory medicine experts whom I moderate are now in the
middle of the clinical content discussion. By the end of 2008 the content
needs to be stable, and go into "clinical" tests. If international
cooperation is an issue, it should be started now, when things are still in
the flow.

Similarly in other countries clinical content is slowly reaching the
attention of national projects (Denmark, Sweden, UK, ..). (I am putting an
excel list of that together).

Now:
The question is: Is DCM willing to accommodate this "clinical" discussion?

I agree with Stef, in that it might be wise to "separate those two
discussions", possibly by forming a subgroup which only addresses the
clinical content questions, and does not get into RIM and technical matters.

Of course such a group would have to have a very close connection to the
"RIM" group, to provide feedback and receive technical guidance, but that
could be "in the background", and "hidden" from the clinicians.

I would be very happy to join such a group, and help to organize a "meeting
ground" for clinicians, who are not able to contribute to RIM questions. Are
there others? How do you see that?

I hope to hear from you, to cheer up a very sad Austria, which got kicked
out of the European soccer championships by Germany yesterday, on home
ground. But this is another long story, see you around,
Stefan Sauermann

Acting Program Director
Biomedical Engineering Sciences (Master)
University of Applied Sciences Technikum Wien
Hoechstaedtplatz 5, 1200 Vienna, Austria
Tel: ++43-(0)1- 333 40 77 - 988
sauermann@technikum-wien.at
http://www.technikum-wien.at

25

Thomas,

We need to provide three types of patterns as sub-archetypes.

One of them is the semi-quantitative expression.

Gerard

what would we do with urinalysis ordinals then: trace, +, ++, +++, etc?

– –
Gerard Freriks, MD
Huigsloterdijk 378
2158 LR Buitenkaag
The Netherlands

T: +31 252544896
M: +31 620347088
E: gfrer@luna.nl

Those who would give up essential Liberty, to purchase a little temporary
Safety, deserve neither Liberty nor Safety. Benjamin Franklin 11 Nov 1755

26

Stef Verlinden wrote:

Question is, is a (part of) the Barthel index score: (needs) little
help (to be mobile) (see my response to Heathers mail as well) an
observation or an interpretation/ evaluation. I would say it's an
evaluation.

*could 10 randomaly chosen occupational therapists come up with the
same
answer to the question? If yes, it is an observation. What does 'a
little help' mean? What does 'mobile' mean?

That's my point so in my opinion it's an evaluation.

27

Hi Stef,

This is an issue that gets raised not infrequently. I’ve gradually been distilling it down to simpler terms and hope this can clarify.

· An observation is something measured, observed or heard – effectively covering all history and examination, including information provided/reported by the patient or third party.

· An evaluation is information generated by the clinician eg “On the basis of these facts (ie the observations recorded above) it is my opinion now that this patient is suffering from …, or has risk of …, etc”

On this basis, your Barthel score example itself is still an observation.

Heather

28

This I don’t understand. Can you please elaborate on that?

Cheers,

Stef

29

Hi Heather,

OK, if that’s the consensus it’s fine with me. Although I have the idea that your definition and the one the Thomas provides are different.

Thomas stated:
‘… If however, the word ‘high’ is being used by the clinician to mean ‘this patient is hypertensive’, i.e. the BP is too high, then it is an evaluation.
And that’s why words like ‘hypertensive’ exist. In this second case, the band of values that correspond to ‘high’ may vary with the patient, e.g. sex, weight, age, pregnancy, diabetic, or just plain personal variation…’

My point is that ‘high’ and ‘little’ are subjective terms (like the --. -, 0, +, ++ scale that Gerard uses as an example) and needs objective criteria (F.i. a little help with mobilization means less than 10 minutes help per 24 hours) in order to be able to provide a reproducable score between different health care providers.
Where do we store the input data (how many minutes of help are provided per timeframe) for that assesment and the criteria themselves?

Right now, I don’t see the difference between:

  • spider angioma (symptom) = liver cirrhosis (interpretation)

and

  • less than 10 minutes help per day (this seems a ‘symptom’ to me) = little help (this seems an interpretation to me)

Does that mean that the diagnosis liver cirrhosis is an observation as well?

Cheers,

Stef

Hi Stef,

This is an issue that gets raised not infrequently. I’ve gradually been distilling it down to simpler terms and hope this can clarify.

· An observation is something measured, observed or heard – effectively covering all history and examination, including information provided/reported by the patient or third party.

· An evaluation is information generated by the clinician eg “On the basis of these facts (ie the observations recorded above) it is my opinion now that this patient is suffering from …, or has risk of …, etc”

On the basis of the fact that this patient requires 6 minutes help with his mobility /24 hours it is my opinion that this patient needs little help…

30

Hi,

For me the constituting elements are Observations expressed following a semi quantitative documentation pattern.
The Barthels Index is an Evaluation because an algorithm calculates, interprets, the observations and transform it to a new semi-quantitative value.

Gerard

Question is, is a (part of) the Barthel index score: (needs) little help (to be mobile) (see my response to Heathers mail as well) an observation or an interpretation/ evaluation. I would say it’s an evaluation.

– –
Gerard Freriks, MD
Huigsloterdijk 378
2158 LR Buitenkaag
The Netherlands

T: +31 252544896
M: +31 620347088
E: gfrer@luna.nl

Those who would give up essential Liberty, to purchase a little temporary
Safety, deserve neither Liberty nor Safety. Benjamin Franklin 11 Nov 1755

31

Stef Verlinden wrote:

Hi Heather,

OK, if that's the consensus it's fine with me. Although I have the
idea that your definition and the one the Thomas provides are different.

Thomas stated:
'........ If however, the word 'high' is being used by the clinician
to mean 'this patient is hypertensive', i.e. the BP is too high, then
it is an evaluation.
And that's why words like 'hypertensive' exist. In this second case,
the band of values that correspond to 'high' may vary with the
patient, e.g. sex, weight, age, pregnancy, diabetic, or just
plain personal variation......'

My point is that 'high' and 'little' are subjective terms

they may or may not be. They are objective if they are always generated
repeatably by a direct observational protocol that works the same for
all patients (e.g. 'high' is always > 140mmHg), e.g. a machine or person
who does some measurement and then reads off the value 'high'. They are
subjective if they are an opinion about this particular patient's state
of health, based on another observed value e.g. a reading off the
sphygmo or other BP device.

(like the --. -, 0, +, ++ scale that Gerard uses as an example) and
needs objective criteria (F.i. a little help with mobilization means
less than 10 minutes help per 24 hours) in order to be able to
provide a reproducable score between different health care providers.
Where do we store the input data (how many minutes of help are
provided per timeframe) for that assesment and the criteria themselves?

Right now, I don't see the difference between:

- spider angioma (symptom) = liver cirrhosis (interpretation)

and

- less than 10 minutes help per day (this seems a 'symptom' to me) =
little help (this seems an interpretation to me)

the first is a (presumably) repeatable quantitative measurement,
generated by a standard observational protocol, and the same answer
would be generated if any other doctor or patient were to perform the
measurement. The second is probably an observation, but at a coarser
grain of quantisation, assuming the word 'little' is understood in the
same way by all physicians who might perform the observation, and if it
would be applied in the same way for any patient.

Does that mean that the diagnosis liver cirrhosis is an observation as
well?

No, it is clearly an Evaluation - you cannot observe liver cirrhosis,
only signs and symptoms that together enable you to classify the patient
as one of those individuals who match the pattern that we call 'liver
cirrhosis' to which is attached a theory of underlying physiological
process, which is what enables us to predict what will happen and also
to try and treat it.

I think in general the way we have to look at these kinds of questions
is to classify what we are trying to do in each case. Is it:
a) to gather evidence upon which assessments can be made?
b) to make an assessment based on some measured or observed evidence? An
assessment is someting that leads to action (which might be to perform
further observation)

- thomas

32

We still can’t agree, Gerard;-)

Barthels Index is a consistent way to gather evidence about a patient’s state – repeat it in a month’s time and you get a consistent answer that reflects the change in the patient’s state – as per Thomas’ way of describing an observation class, and a direct output from taking a history or examining a patient as per my description. The number that is the sum of all the individual constituent choices – it still reflects just the total, not an assessment or interpretation. It can be done online - http://www.patient.co.uk/showdoc/40001654/ - without any clinical input, expertise or interpretation.

The clinical extrapolation that follows might conclude that this patient is ‘at risk of falls’- this is an evaluation class. The subsequent plan that the patient needs interventions including a referral to a Falls clinic or a home visit by an occupational therapist for bathroom aids is characterized by an instruction class.

BTW did you have a good holiday?

Cheers again

Heather

33

Heather Leslie wrote:

We still can’t agree, Gerard;-)

Barthels Index is a consistent way to gather evidence about a
patient’s state – repeat it in a month’s time and you get a consistent
answer that reflects the change in the patient’s state – as per
Thomas’ way of describing an observation class, and a direct output
from taking a history or examining a patient as per my description.
The number that is the sum of all the individual constituent choices –
it still reflects just the total, not an assessment or interpretation.
It can be done online - http://www.patient.co.uk/showdoc/40001654/ -
without any clinical input, expertise or interpretation.

The clinical extrapolation that follows might conclude that this
patient is ‘at risk of falls’- this is an evaluation class. The
subsequent plan that the patient needs interventions including a
referral to a Falls clinic or a home visit by an occupational
therapist for bathroom aids is characterized by an instruction class.

BTW did you have a good holiday?

*I suspect that philosophically the truth is somewhere in between. The
Barthel, as Gerard has pointed out is something like a protocol for
generating a classification of an inidividual, which is something like
an assessment of some kind. Normally (in my understanding) further
assessments would be needed on people who come out badly on the Barthel
index. Nevertheless, it could be looked upon as a little tool that
performs your observation and generates a rough assessment. For
practical purposes I think it is better to treat it as an observation
though, since it is repeatable, objective (as long as the protocol is
followed) and it is something used as evidence for a real assessment.

- thomas

34

Maybe I repeat what numerous others have said or just add confusion,
but there is a professional society dimension to this too:
- I believe some clinicians would regard it an instrument.
- It was established by a member / members of a professional society
- It has been, and is used as a measurment instrument for scientific
purposes within the professional society
- To use the Barthel index while solving the problems of individual
patients can be compared to using a term in the language of the
professional society
- To use the index while conducting clinical work opens up for the
possibility that the patients case might become a case in a scientific
publication (e.g. an outcome study).

Arild FAxvaag

35

Hi Heather,

Barthels Index is a consistent way to gather evidence about a

patient’s state –

I just found out that, when looking for an ‘example’ in the Barthels index, I’ve overlooked the adjacent column in which the ‘criteria’ are stated (Little help is defined as ’ one person for supervision or some help). Furthermore ‘little help’ is a score for transfer from bed to chair and not for mobility. Sorry for the confusion that I’ve created.

So, I can see your point that, since all these parameters which are scored for are well defined, the Barthels index should be regarded as an instrument to consistently gather information about a patients state.

The point I was trying to make, and I don’t think we disagree on that, is that subjective scores (for example high/ low), for which there is no universal agreement upon the criteria for that score, are evaluations. In that case people can use their own criteria and/or different standards/ protocols and one needs to know according to which criteria/ standard/ protocol it is high or low. For example ‘high blood-pressure’ is an evaluation of a blood-pressure value based on criteria/ standard/ protocol X. Somebody else who is using criteria/ standard/ protocol Y may evaluate the same blood-pressure value as normal.

What still puzzles me, is that if the criteria are universally accepted the score becomes an observation while if the criteria can vary it becomes an evaluation. The thing that immediately pops into my mind is that since there are at least 3 different versions of the Barthel index (as mentioned in a previous mail) one can wonder how universal these criteria are. So at least it should be known which version is used.

Cheers,

Stef

36

Hi Stef,

I’m glad we are back in alignment again;-)

Barthel Index and Apgar are pragmatic examples where the components are powerful together, but are not really suitable for the ’pure’ modeling we need to aim for in general – ie the concept of a maximal dataset for universal use case. Apgar is more complicated again as it has specific events involved as well – ie 1 min, 2 min readings etc.

The issue of different criteria is a real one, and I understand that with links we will be able to connect a diagnosis back to the original evidence, which will be important – this is new territory to me, but I believe covered by the RM. Others might be able to provide more information.

And re your final point, from memory the difference between some of the versions of Barthel are quite significant. If other versions are being used, then we will have to consider specialization or possibly even separate archetypes – I don’t have much of a feel for the clinical requirements here, yet.

Cheers

Heather

37

Dear all,

For quite some time as was confused as most of you when it comes to thinking about
Observation and Evaluation.

The reason is/was that most clinicians, and GPs in particular, know the Larry Weed Subjective, Objective, Evaluation and Plan way of documenting in records.

It all became very clear to me that the major differentiator to make the decision between Observation and Evaluation is to look at the ‘documentation pattern’ that each of these archetypes provide you.
The choice is not whether it is an uttering of the patient or an observation by the documenter or whether it is an idea generated in the mind of the documenter.

It is all about documentation and patterns provided by the different type of archetypes.
So there are four basic ‘Documentation Patterns’: Observation, Evaluation, Instruction and Action.

These ‘Documentation Patterns’ have nothing to do with Larry Weeds SOEP stuff.

Gerard

I am in the process of documenting my current feelings about the
Observation/Evaluation debate and came across this alternative
definition in a different setting

– –
Gerard Freriks, MD
Huigsloterdijk 378
2158 LR Buitenkaag
The Netherlands

T: +31 252544896
M: +31 620347088
E: gfrer@luna.nl

Those who would give up essential Liberty, to purchase a little temporary
Safety, deserve neither Liberty nor Safety. Benjamin Franklin 11 Nov 1755

38

Observation = A Documenting Pattern to record observed facts about the state in the patient system. Leading to a pattern to document an observation at one or more points in time, describing the status of the observed object, and method used.
Evaluation = A Documenting Pattern to record subjective opinions about processes in the patient system. Leading to a pattern to document a personal opinion. At one point in time, not only based on facts, but based on experience and expertise, hunches, thoughts, etc, etc.

Reading the above I see some potential grey areas.
Several observations done by clinicians take the form of an opinion. The auscultation of a heart murmur when documented by a device is certainly an Observation. But when a human does it, the human will take on the role of a device. He will document: I declare that I heard a murmur of a certain type in this patient using my own expertise and experience as ‘device’. It looks like an evaluation. This statement is actually an observation about the patient system but expressed as a an opinion. When a human is acting as a machine to record facts (even when experience and expertise is called for) it will be recorded using the Observation Documenting Pattern not with the machine as method but the human. It is the recording of a state of something in the patient system.

When facts , expertise, experience, hunches, thoughts, transform data into information in the head of the documenter the at a higher level of abstraction a notion is formulated with the character of a declaration about a process in the patient system. This declaration helps to understand the states in the patient system in the past, the present and predicts states in the future.

To document something about the state of something in the patient system, at point is time, using a specified method we have to use the Observation Documenting Pattern.
To document something about a process in the patient system we use the Evaluation Documenting Pattern.

Gerard

In the same way, Evaluations in the clinical information cycle will
often select certain items already mentioned in Observations - but note
they are not just repeating them, they are really selecting and usually
saying something about them. E.g. that the mother’s breast cancer
represents a risk for the current patient (the daughter).

The practical upshot of this is that there will be a need to have some
archetyype elements in common with both Observation and Evaluation
archetypes.

– –
Gerard Freriks, MD
Huigsloterdijk 378
2158 LR Buitenkaag
The Netherlands

T: +31 252544896
M: +31 620347088
E: gfrer@luna.nl

Those who would give up essential Liberty, to purchase a little temporary
Safety, deserve neither Liberty nor Safety. Benjamin Franklin 11 Nov 1755

39

Gerard Freriks wrote:

To document something about the state of something in the patient system, at point is time, using a specified method we have to use the Observation Documenting Pattern.
To document something about a process in the patient system we use the Evaluation Documenting Pattern.

This is a very useful discussion. The above is an interesting way of looking at the problem, but we need to be careful about what it means.

  1. we can only observe phenomena via the states they give rise to at points in time. We can make multiple samples if we want.
  2. we can’t directly observe a (temporal) process. The best we can do is to make observations of the state of something and then surmise that a particular process is present - i.e. it is an opinion based on the observed samples.

Making a diagnosis or any other kind of assessment is about identifying an underlying process. It is the same as any other evidence-based scientific theory - to be ‘good’, it must have good explanatory power, and it must have good predictive power. But it is still an opinion.

It is now interesting to think about Barthel or Apgar. They are clearly observational, at least partly, but do they contain opinions based on the evidence? One could argue that they do, since the point levels that designate different categories of babies or elderly patients are a kind of standard assessment about the meaning of the point levels. This would be the same situationn as a BP meter that has a red zone or indication when the systolic is above 180mmHg. Practically speaking I believe it is better to keep them as observations and treat the output as a kind of observation as well, which will act as the input to the next stage of proper assessment. For example, a low Apgar doesn’t on its own tell what is wrong with the baby, only that something needs to be done fast; an doctor still needs to assess and act.

  • thomas
40

Thomas,

To document something about the state of something in the patient system, at a point in time, using a specified method we have to use the Observation Documenting Pattern.
To document something about a process in the patient system we use the Evaluation Documenting Pattern.

Bartel and Apgare and a lot more of those indexes are based on observations.
When the observation is a measurement then this is transformed into a semi-quantitative observation using some rules.
Other observations are not measured but (based on experience, expertise) clinical people produce directly the observations in that semi-quantitative way.
Using an algorithm the Index is calculated.

These Indexes indicate in summary the status in the patient system by observing a few aggregated phenomena.
Indexes are observation that will use the Observation Documenting Pattern.

Sometimes a real measurements are transformed using classification rules as method and turned into a semi-quantitative measurements.
Sometimes clinicians document the semi-quantitative measurements directly. Then the human is the method.
The Index is calculated using the algorithm as the method.

These indexes tell us nothing about underlying processes in the patient system.
Only that, based on aggregated observations of states, healthcare providers are able to see an indication of severity and the need to draw conclusions and make a plan.

Gerard

Gerard Freriks wrote:

To document something about the state of something in the patient system, at a point in time, using a specified method we have to use the Observation Documenting Pattern.
To document something about a process in the patient system we use the Evaluation Documenting Pattern.

This is a very useful discussion. The above is an interesting way of looking at the problem, but we need to be careful about what it means.

  1. we can only observe phenomena via the states they give rise to at points in time. We can make multiple samples if we want.
  2. we can’t directly observe a (temporal) process. The best we can do is to make observations of the state of something and then surmise that a particular process is present - i.e. it is an opinion based on the observed samples.

Making a diagnosis or any other kind of assessment is about identifying an underlying process. It is the same as any other evidence-based scientific theory - to be ‘good’, it must have good explanatory power, and it must have good predictive power. But it is still an opinion.

It is now interesting to think about Barthel or Apgar. They are clearly observational, at least partly, but do they contain opinions based on the evidence? One could argue that they do, since the point levels that designate different categories of babies or elderly patients are a kind of standard assessment about the meaning of the point levels. This would be the same situationn as a BP meter that has a red zone or indication when the systolic is above 180mmHg. Practically speaking I believe it is better to keep them as observations and treat the output as a kind of observation as well, which will act as the input to the next stage of proper assessment. For example, a low Apgar doesn’t on its own tell what is wrong with the baby, only that something needs to be done fast; an doctor still needs to assess and act.

  • thomas

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Gerard Freriks, MD
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T: +31 252544896
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