Wednesday, December 13, 2006

Is SNOMED CT a Practical Usable Clinical Terminology Today?

In a recent posting at the E-Health Insider web-site it is reported that the Royal College of Physicians is urging a “universal and rapid SNOMED deployment” to be undertaken by the UK Connecting for Health IT Program.

The article can be found here:

More interesting than the article is an anonymous response to the suggestion found at the bottom of the article. This is worth quoting in full as it goes to make some points and provide some useful resources for those interested in the area of practical, clinically useful SNOMED CT implementation.

“12 Dec 06 12:29

SNOMED: caveat emptor

Readers of this article (and the RCGP) are advised to check the detail before rushing into demands for immediate SNOMED implementation.

Major suppliers, would be implementers and academics are on public record stating SNOMED has manifest and significant quality control and implementation issues.

On a purely pragmatic level, clinical code sets supporting QOF/QMAS on the DoH website (URL changes almost daily :-( ) for SNOMED have not been updated since 2005 release (unlike those for the Read Codes which are up to date). This latter alone is unlikely to encourage jobbing GPs to queue up as guinea pigs for the 'imminent' releases of SNOMED enabled systems from EMIS, In Practice and others.

It just isn't as simple as whip the system suppliers I'm afraid.”

A review of the material found on these pages certainly raises some interesting and very complex questions and I would suggest anyone with an interest in the area review these two sites and the links / downloads provided carefully.

The messages I came away from all this material with were as follows:

1. If David Markwell’s presentation from March 2006 is to be believed the work of encapsulating the complexity for SNOMED CT behind a useable clinically friendly interface has yet to be completed. Without well engineered seamless interfaces to the use of SNOMED CT adoption and use of the terminology will be very slow indeed

2. The Kaiser Permanente implementation of SNOMED CT within its EPIC software implements a narrow subset of the full contents of SNOMED to make clinical coding and billing easier.

3. Professor Alan Rector (a global terminology guru if there is one) from Manchester University has recently said in a presentation that “Unless we can formalise the mutual constraints ... HL7 v3 + SNOMED = Chaos'. 'The documentation is beyond human capacity ... to write or to understand'.”

4. Other groups appear to be really struggling to deploy usable clinician friendly systems.

5. There are some significant academic linguists and ontologists who have very significant concerns about the underlying data model on which SNOMED CT is based.

6. The emergence of supporting terminologies in areas where localisation to a specific country is needed (e.g. in the local formulary) has been slower that might have been expected.

7. There is at least some concern regarding the overall data quality of the material already contained in SNOMED CT.

8. There also seem to some harmonisation issues between HL7 V3.0, CEN/ISO Standards and OpenEHR with Archetypes which indirectly impinge to some extent of terminology use.

What does all this mean practically?

I think that it is at least possible that large scale deployment of clinician friendly SNOMED CT may be more delayed than is anticipated at present – i.e. out to beyond 2010 and there is even the possibility that it may all prove ‘too hard’ and some simpler better designed approach – based on the lessons learnt from SNOMED CT – may need to be engineered.

Whatever happens it seems clear all those interested in the area should spend some time getting familiar with the current state of play so they can formulate, for themselves, informed estimates of just when systems which fulfil the promise of SNOMED CT are likely to be available.

I for one will not be holding my breath. Just as HL7 V3.0 and openEHR have taken over a decade to be developed and are not yet quite ready for ‘prime time’ as far as I know I suspect history will repeat with SNOMED CT.

I hope I am wrong!



Anonymous said...

David, any chance you can alter the format of your blog so that quoted text is easily distinguishable?

Aus HIT Man said...


I do place all quotes within quotes but have had trouble with publishing when I make the formats more complex - so am hesitant to do more. Looking at the last few my parts and the quotes are pretty clear I thought.


Anonymous said...

I have the feeling that HL7 V3 and OpenEHR are a bit immature in their clinical model when compared with Snomed-CT. This is the reason for the difficulty rather than a problem with SNOMED-CT.

HL7 V3 and OpenEHR moth have basic modeling constructs, neither of which is as mature or powerful as the SNOMED-CT model. If they would both drop the conflicting pieces and just handle what SNOMED-CT does not do - eg Patient demographics, dates, Quantities etc then we could have a common clinical model.

Archetypes and the SNOMED-CT model are really approaching the same problem from different ends and in the end they will merge, but the semantic model behind snomed is solid and elegant, if at this time, a little incomplete and erroneous in places.

If you read about the semantic web you will find the basic models almost exactly the same, and SNOMED-CTs can first and does work now! Its far easier to be critical than to do the work to understand what lies under the surface.

Aus HIT Man said...


I think if you ask a range of experts you may find there are some who have very significant concerns about the SNOMED-CT data model and especially about how it can be made to work with EHR constructs.

Remember we have no really usable, complete and scaled implementations of all three as far as I know.

Let me know if I am behind the times.


أحمد شطا said...

More than a whole year has passed since the last comment was added, any news Dr. David?

Anonymous said...


We have a free Microsoft Excel Add-in that provides a fast and easy way to look up the Snomed codes which you can download from The list automatically limits as you type saving time when you need to reference these throughout your day.

The program was developed in Excel so that you can easily add and delete codes as required. In fact you can use the Lookup program for any data you like, not just Snomed codes. Simply paste in any two columns of data that you need to filter quickly and start typing.

Perhaps some of your readers may find this useful.


Anonymous said...

The reference made in 2006 about HL7 and OpenEMR being a bit immature may now be a reality. It is my understanding that a US based "diagnostic and lab" company have built an interoperable system more intense than any thing like it. I heard about it at HIMMS this year. Maybe SNOMED CT will finally gain some traction. Did you know there are trade healthcare writers who have never heard of SNOMED CT? Isn't implementing any EMR with standardized terminology putting the cart before the horse? I'm just surprised where the emphasis is on this subject. Thanks for your insight!

MIInfo said...

Hi, I have been following your posts for sometime now. I wanted to know if you would be having a link to the SNOMED CT downloads.

Please let me know.



Aus HIT Man said...

Sorry No,

You need a license to download SNOMED.