Question on the role of EHR reference models for achieving functional interoperability

Technical (archive)
1

Dear all,

I would like to ask you for your opinion on a statement in ISO/DTR 20514 (Definition, scope and context of the EHR), which says that “[…] a standardised EHR reference model is required for achieving functional interoperability […]” (page 7 of ISO 20514).

Functional interoperability is defined as “the ability of two or more systems to exchange information (so that it is human readable by the receiver)”.

I am now wondering why an EHR reference model is seen to be REQUIRED for achieving functional interoperability. If I exchange bare PDF-documents (without any describing metadata) between two EHR systems, then I would say there is a good chance that these docs are readable by a human receiver and thus functional interoperability should be achieved although clearly an EHR reference model is not used.

I agree that an EHR reference model alone is not enough to achieve semantic interoperability (agreed archetypes and terminology are missing) and therefore by using an EHR reference model alone one can still only achieve functional interoperability. However, this seems to me as some kind of “advanced functional interoperability”, where the receiving EHR system knows the basic components (the RM classes and their attributes) from which EHR information is composed.

So I have the impression that an EHR reference model helps to achieve some kind of “advanced functional interoperability”, but I would not say that it is REQUIRED to achieve functional interoperability (refering to the PDF-exchange as a counter-example).

What do you think?

Thank you for any comments and best regards,
Georg

2

Dear Georg,

3

Hi Georg,

I agree with your argument.

Distinguishing "advanced functional interoperability" from PDF like
"functional interoperability" is helpful as the information can be
presented in a more or less customised way leveraging the underlying
RM classes -> Ocean's EHRview
(https://wiki.oceaninformatics.com/confluence/display/ocean/EhrView+Demonstration
- unfortunately currently unavailable) is an example for such a
generic display mechanism. Obviously if the archetypes are known as
well more sophisticated customization is possible.
Every clinical information system could implement a similar mechanism
to display openEHR data (even without archetypes) more or less adapted
to their environment. However, this is only helpful for read-only
interfaces. To be able to edit the data the archetypes have to be
known!

Cheers, Thilo

4

hi Thilo

I would like to ask you for your opinion on a statement in ISO/DTR 20514
(Definition, scope and context of the EHR), which says that "[...] a
standardised EHR reference model is required for achieving functional
interoperability [...]" (page 7 of ISO 20514).

Functional interoperability is defined as "the ability of two or more
systems to exchange information (so that it is human readable by the
receiver)".

I am now wondering why an EHR reference model is seen to be REQUIRED for
achieving functional interoperability. If I exchange bare PDF-documents
(without any describing metadata) between two EHR systems, then I would say
there is a good chance that these docs are readable by a human receiver and
thus functional interoperability should be achieved although clearly an EHR
reference model is not used.

well, not so fast. If you are exchanging pdf documents, you need some rules
about how they are exchanged, and when, and then what happens as a consequence.
These can be rather informal, but nevertheless, they must exist. And once they
do, aren't you on the way to have an EHR reference model?

Then there's the question of interoperability. Generally what you describe
is *integration* not interoperability. Picking these two apart is a fun game,
but generally inteoperability is more about plug-n-play where as integration
is about two systems made to work together. As you move your example from two
to many systems, you'll be increasingly moving towards a standardised EHR
reference model.

And there's no semantic anything in sight yet!

Grahame

5

Hi Grahame,

well, not so fast. If you are exchanging pdf documents, you need some
rules
about how they are exchanged, and when, and then what happens as a
consequence.
These can be rather informal, but nevertheless, they must exist. And once
they
do, aren't you on the way to have an EHR reference model?

You are right, there must be some kind of rules when PDFs are exchanged to
ensure that they are human readable and can be trusted by the receiver (I
also absolutely agree with Stef here), so for example the natural language
used must be agreed in advance and the meaning of uncommon medical notions
should also be agreed (although this point probably already goes in the
direction of semantic interoperability).
Anyway, with the notion "standardized EHR reference model" as used within
ISO 20514, I rather associate in my head a model such as the openEHR
reference model or EN/ISO 13606-1. Strangely the term "standardized EHR
reference model" is not itself defined within ISO 20514, but there is a
reference to the notion "EHR architecture", which is defined in 20514 as
"the generic structural components from which all EHRs are built, defined in
terms of an information model".
So, it probably depends on how one interprets the notion "standardized EHR
reference model" => if it is interpreted as "some kind of - maybe also
informal - rules between sender and receiver" than I think it is required
for functional interoperability. If it is interpreted as a model such as the
openEHR reference model or EN/ISO 13606-1, then I would say it supports a
"higher level of functional interoperability" but is not actually required
for achieving basic functional interop.

Then there's the question of interoperability. Generally what you describe
is *integration* not interoperability. Picking these two apart is a fun
game,
but generally inteoperability is more about plug-n-play where as
integration
is about two systems made to work together. As you move your example from
two
to many systems, you'll be increasingly moving towards a standardised EHR
reference model.

In my question I actually referred to the definition of "functional
interoperability" as is given in ISO 20514.

Cheers, Georg

6

You did indeed quote the definition from 20514 indeed. And I agree that the
implication of the standard is that you can't do things without a
formal all-encompassing top to bottom model. So I think you're right
that the standards over-state the case. (but hey, what standard doesn't?)
I was just pointing out that it's not that far over-stated though.

Grahame

7

Dear Georg,

-1-
When interpreting text from standards it is a useful practice to look at the definitions.

3.9
electronic health record (EHR) - for integrated care (ICEHR)
a repository of information regarding the health status of a subject of care in computer processable form,
stored and transmitted securely, and accessible by multiple authorised users. It has a standardised or
commonly agreed logical information model which is independent of EHR systems. Its primary purpose is the
support of continuing, efficient and quality integrated health care and it contains information which is
retrospective, concurrent, and prospective
3.10
electronic health record (EHR) – basic generic form
a repository of information regarding the health status of a subject of care, in computer processable form
NOTE The definition of the EHR for integrated care in 3.9 should be considered the primary definition of an electronic
health record. The definition of a basic-generic EHR is given only for completeness and to acknowledge that there are still
currently many variants of the EHR in health information systems which do not comply with the main (ICEHR) EHR
definition (e.g. a CDR complies with the basic-generic EHR definition but not with the ICEHR definition)

3.27
shareable EHR
an EHR with a commonly agreed logical information model
NOTE 1 The shareable EHR per se is an artefact between a basic-generic EHR and the Integrated Care EHR (ICEHR)
which is a specialisation of the shareable EHR. The shareable EHR is probably of little use without the additional clinical
characteristics which are necessary for its effective use in an integrated care setting.
NOTE 2 Whilst the ICEHR is the target for interoperability of patient health information and optimal patient care, it
should be noted that the large majority of EHRs in use at present are not even shareable let alone having the additional
characteristics required to comply with the definition of an Integrated Care EHR. A definition of a basic-generic EHR has
therefore been included to acknowledge this current reality.

It is clear to me that they defined the EHR as what is called the ‘Sharable EHR’.
Within the light of this definition to have the Reference Model is a requirement.

-2-

3.25
semantic interoperability
the ability for information shared by systems to be understood at the level of formally defined domain concepts

Semantic Interoperability is more than functional interoperability.
For the latter a piece of written paper or a PDF is enough.
In ISO 20514 one is clearly dealing about full semantic interoperability

-3
When a thing is required most often this is not sufficient by itself.
Other requirements have to be fulfilled in addition.
For semantic interoperability we need terminologies and ways to express sensible things in a context (archetypes and templates).
We need in addition a syntax and this is the Reference Model.

-4-
What they actually write and describe as pre-requisites is:

In order to achieve semantic interoperability of EHR information, there are four prerequisites, with the first two
of these also being required for functional interoperability:
a) a standardised EHR reference model, i.e. the EHR information architecture, between the sender (or
sharer) and receiver of the information,
b) standardised service interface models to provide interoperability between the EHR service and other
services such as demographics, terminology, access control and security services in a comprehensive
clinical information system,
c) a standardised set of domain-specific concept models, i.e. archetypes and templates for clinical,
demographic, and other domain-specific concepts, and
d) standardised terminologies which underpin the archetypes. Note that this does not mean that there
needs to be a single standardised terminology for each health domain but rather, terminologies used
should be associated with controlled vocabularies.

In the context of all definitions I read that EHR-systems that have only a Reference Model and Service Interface models can interoperate at the functional level.
And this is true.
When systems store information using the CEN/openEHR Reference Model there is enough information from the RM to represent the data in a for humans understandable way.
It then acts exactly as a PDF!
Humans when reading PDF’s can interpret only because of their shared implicit underlying Reference Model that we know by the name: Syntax of language.

WIth regards,

Gerard Freriks

Dear all,

I would like to ask you for your opinion on a statement in ISO/DTR 20514 (Definition, scope and context of the EHR), which says that “[…] a standardised EHR reference model is required for achieving functional interoperability […]” (page 7 of ISO 20514).

Functional interoperability is defined as “the ability of two or more systems to exchange information (so that it is human readable by the receiver)”.

I am now wondering why an EHR reference model is seen to be REQUIRED for achieving functional interoperability. If I exchange bare PDF-documents (without any describing metadata) between two EHR systems, then I would say there is a good chance that these docs are readable by a human receiver and thus functional interoperability should be achieved although clearly an EHR reference model is not used.

I agree that an EHR reference model alone is not enough to achieve semantic interoperability (agreed archetypes and terminology are missing) and therefore by using an EHR reference model alone one can still only achieve functional interoperability. However, this seems to me as some kind of “advanced functional interoperability”, where the receiving EHR system knows the basic components (the RM classes and their attributes) from which EHR information is composed.

So I have the impression that an EHR reference model helps to achieve some kind of “advanced functional interoperability”, but I would not say that it is REQUIRED to achieve functional interoperability (refering to the PDF-exchange as a counter-example).

What do you think?

Thank you for any comments and best regards,
Georg

– –
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

8

Georg Duftschmid wrote:

9

Hi Thomas,

no reference model = no computability, including queryability. To
overcome that, if you use PDFs, plain text etc, you need structured
meta-data. As soon as you need that (e.g. like IHE) you need a model of
it. As soon as it tries to be more sophisticated, the model becomes more
complex. If we want queryable, computable data (e.g. for decision
support, research), you have to have models. Otherwise the software
doesn’t know what the data mean.

If I understand you right, you argue that a reference model is required if SEMANTIC interoperability (you refer to software that must know what the data mean) has to be achieved. I would fully agree here.

What makes me wonder about the statement in ISO 20514 is that they consider an EHR reference model as required for FUNCTIONAL interoperability
=> “In order to achieve semantic interoperability of EHR information, there are four prerequisites, with the first two of these also being required for functional interoperability:
a) a standardised EHR reference model, i.e. the EHR information architecture, between the sender (or sharer) and receiver of the information,
b) …”

They further define functional interoperability in ISO 20514 as “the ability of two or more systems to exchange information (so that it is human readable by the receiver)”.
I would think that human readability and thus functional interoperability can also be achieved without a standardised EHR reference model.

Cheers, Georg

10

Georg Duftschmid wrote:

11

I agree with Thomas and Graham that the initial argument really hinges
on whether the most minimum communication of an email with attached
clinical pdf, by being human interpretible meets the definition of
'functional interoperabilliy.

I would say no, simply because it then makes no distinction between
simple communication (which can be extremely helpful) and 'functional
interoperability' which I believe carries some notion of
computability, helping place the document or information therein, more
precisely within the recipient system, but falling short of the
precise computability suggested by 'semantic interoperability'.

Semantic interoperability is hard to achieve because it requires both
technical consensus and human, clinical agreement. I am starting to
think that one of the values of archetypes is that they provide a
natural levle of granualarity within the record that immediatley
supports funtional interoperability, whilst allowing for the organic
development of semantic interoperability.

As an example, within the NHS, there is a workstream devoted to
interoperability between the heath and social care services. Because
of the lack of consensus around the data items to be included, it has
been decided initially to use a CDA wrapper with some broad
'functional' headings e.g Past Medical History, Mobility Assessment,
Continence Assessment.

These accord very nicely to probable or actual archetypes which
immediately support a level of functional interoperability.The maximal
dataset approach allows each archetype to contain mutliple varieties
of e.g. mobility assessment and backed by the reference model, enables
minimal 'functional' representations of these in non-native systems.
Semantic interoperability will only come about when 2 or more agencies
agree to share a particular variety of mobility assessment, via
further template level constraint, adjusting their internal processes
to match but this is a social/organisational commitment, requiring no
change in the technical representation on the archetype.

Ian

Dr Ian McNicoll
office / fax +44(0)141 560 4657
mobile +44 (0)775 209 7859
skype ianmcnicoll

Consultant - Ocean Informatics ian.mcnicoll@oceaninformatics.com
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