Green CDA: The missing link in EHR interoperability?

The Clinical Document Architecture (CDA) data standard, which is based on the extensible markup language, or XML, is used in many electronic health record (EHR) systems. Health Level 7 International has developed a lightweight version known as the HL7 Green CDA standard. Although the CDA can represent any aspect of the EHR system for any purpose, at least in principle, the Green CDA standard tries to be simpler than the CDA, so it requires less computing power and is more human-readable.

At the Healthcare Information and Management Systems Society's HIMSS 2011 conference, we caught up with Dr. Bob Dolin, chairman of the HL7 board of directors. Here he explains the new data standard's significance and tells us what's new. In addition, he gives us an exclusive scoop on an alternative name for Green CDA that was left on the cutting room floor.

Let us know what you think about the story; email Don Fluckinger, Features Writer.

Read the full transcript from this video below:

Green CDA: The missing link in EHR interoperability?

Don Fluckinger: Hi. I am Don Fluckinger, Features Writer for
Have you heard about the Green CDA standard? At HIMSS in Orlando,
we caught up with Dr. Robert Dolin, chairman of the HL7 Board of Directors,
to explain this new data standard's significance. Also, he gives us an exclusive
scoop on an alternate name for Green CDA that was left on the cutting room floor.

For our readers who are not completely familiar with it, explain what the
Green CDA is, and how it differs from the traditional clinical document
architecture that we all have come to know and love.

Dr. Robert Dolin: What we have found, if you look at Meaningful Use stage 1,
there is a requirement that a certified EHR be able to produce CCD
documents in the HITSP C32 format. If you look at the HITSP C32
specification, it is a constraint on IHE templates, because IHE templates
are constrained on CCD, and CCD is a constraint on CDA. Some people,
when faced with three levels of indirection are, like, ‘Are you kidding me?'
What we wanted to say was, ‘On the other hand, they like the technology,
they like the fact that underlying all of this, everything is a CDA document,’
so I have CDA documents for CCD, discharge summary, operative reports,
for diagnostic imaging, et cetera. They like the fact that there is a common schema,
and they like the fact that you can just have different profiles, but they do not like
the fact that when you profile this, all of a sudden you have the base standard
that you have to learn, and you now have to learn these profiles, so they are struggling with, ‘How can we simplify the location of any type of template in CDA documents such as
CCD?’ So we came up with Green CDA.

Green CDA is really nothing more than a simplified XML schema. It is simplified,
if you write for that simplified XML schema, you can push a button and boom,
out the back comes a full canonical CDA. You can have a CDA diagnostic
imaging report, it might have its flavor of Green CDA that is just very simple,
geared towards that specific implementation. Likewise, with CCD, there is a
Green CCD, it is just an XML schema that people can write to, and we find that
it dramatically lowers the cognitive process of trying to implement a
CDA-based standard.

Don Fluckinger: How did you come up with "Green?"

Dr. Robert Dolin: I believe the Green CDA phrase itself was invented by
Leora Alschuler. It was because we wanted to, I guess, well, I do not know exactly the
history of where Green CDA came from, but what we said, ‘It is a catchy word.
Everyone is trying to go green now. We believe that this will be good for the
environment,’ meaning the health care environment that people are trying to
implement, so this would be good for healthcare environment.

Don Fluckinger: Interesting. It had less to do with reducing paper.

Dr. Bob Dolin: It had less to do with reducing paper. It had really more to
do with simplifying implementations.

Don Fluckinger: Very well.

Dr. Bob Dolin: I wanted to call it "CDA, Meaningful Use shrinkwrapped."
Then we said, ‘Shrinkwrapping’ is plastic, and that probably does not go
along with the concept of Green CDA.

Don Fluckinger: Where is it in development? Do we have our vendors
supported, or is that two years from now? How would you characterize
where it is?

Dr. Bob Dolin: The actual Green CDA implementation guide will be
published either later this month or early March, the implementation guide
itself is not out yet. When we do publish it -- I will give a talk on Green CDA
tomorrow afternoon -- when we do publish the implementation guide, it has
a complete package for CCD, necessary for Meaningful Use Certification.
There is a Green CCD schema that comes in the package, there is a transform
that will convert that to a canonical CCD that passes validation against the NIST
validator for CCD Meaningful Use Certification. The tools that are necessary most
immediately, that people are struggling most immediately for C32, will be published
as part of the implementation guide.

Don Fluckinger: HL7 today announced another collaboration with ONC
that is somewhat related. Give us a little bit of detail on that.

Dr. Bob Dolin: This is the, HL7 IHE Health Story CDA Consolidation Project.
Here is the problem that we are trying to solve. CDA, who are working with
a group called Health Story, have developed multiple CDA implementation
guides. We developed a history and physical implementation guide, a
diagnostic imaging implementation guide, procedure notes implementation guide;
they were validated at different times. Our process for developing implementation
guides has improved dramatically over the last couple of years. Also, what we did
in this implementation guide a few years ago, we since learned, ‘Maybe that was
quite right,’ so this implementation guide does something, it could be the same,
but there [are] slight differences between them. What we said we needed to do, meanwhile,
when you look at CCD and the templates that people are complaining about the
indirection, what we wanted to do is take all of these templates and implementation
guides and simply reballot them all in one cohesive release package. Whereas,
part of one cohesive package, we could put all the templates in there,
all the implementation guides, make sure there is complete internal
consistency across all the documents. What you'll wind up with in this
package is a single implementation guide that allows you to implement CCD,
discharge summaries, history of physicals, diagnostic imaging report, procedure
notes, all in an internally consistent package.

HL7 and IHE -- IHE I consider to be one of HL7's strategic partners -- we shook
hands and we both agreed that this was going to be important for us to go
in on together, Health Story was a strong component of this project as well.
Fortunately, the stars aligned, and through our negotiations with ONC, it came
that ONC could sponsor this project and use it as a way to test the evolving
ONC of standards and interoperability framework. So here was ONC trying to
develop a standard interoperability framework. Here was HL7, IHE, and Health Story
already converging on something we felt could be a very important initiative,
so the fact that ONC came onboard to help sponsor the project, what can I say,
we just felt it would be a tremendous boost to the whole project, and it is a
great opportunity for us to really test the evolving ONC standard development process.

Don Fluckinger: Thank you very much for your time.

Dr. Bob Dolin: My pleasure, my pleasure.

Announcer: And remember, you do not know HIT until you have read

View All Videos

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.