The Challenge and SNOMED CT

Karen Gibson

The Challenge Significant investment in eHealth is underway Clinical records:

◦ Not only a record for the author◦ Essential to inform the next person in the care

team Clinical safety risks of poor quality, ambiguous

communication Desire to:

◦ make systems more interoperable◦ improve data quality ◦ improve ability to re-use information for reporting,

management etc.

Clinical Terminology is complex

Humans spend 4-10 years learning medical terminology at University!

We need to make their language computable

No silver bullets

Clinicians say things in many different ways◦ Sometimes legibly◦ Often in shorthand

Terminology needs to maintain fidelity of information – be true to what clinician is trying to say

EHR’s need to source information from many different systems◦ Legacy systems with legacy data◦ Legacy terms and ways of coding (if coded at

all)

How do we begin to bring this together?

And do so in a way which ensures stakeholders can be confident that the information is accurate and capable of being aggregated and reused.

What is the answer? SNOMED CT

◦ Most comprehensive clinical terminology available

~ 350,000 concepts~ 1,000,000 terms

◦ Purchased and maintained by a group of collaborating nations for use in their eHealth initiatives (IHTSDO)

Only part of the answer:◦ Supplemented by other terminologies – eg.

medicines and administrative◦ Knowledge of the information model (context)◦ Other emerging technologies (eg. NLP)

What is the problem? SNOMED CT

◦ Complexity ~ 350,000 concepts~ 1,000,000 terms

Only part of the problem◦ Lack of implementation knowledge◦ Lack of tools to assist◦ Lack of funding to meet costs of

implementation◦ ? Lack of will

Some problems have been addressed

IHTSDO has addressed (or is working to address): International Governance Open Standard Intellectual Property Quality ? Mapping to other standard terminologies/ classifications

Others are being tackled by NEHTA: Cost – free to use in Australia (as member of IHTSDO) ‘Australianisation’ National reference sets Medicines component

Key principles/ Traps for new players

Do look to SNOMED CT-AU first

◦It is endorsed by COAG◦It is the most comprehensive clinical

terminology available◦It is supported by NEHTA and IHTSDO

SCTID: 22298006

SNOMED CT-AU A concept and its descriptions

Myocardialinfarction

Synonym MI - Myocardial infarctionSCTID: 1784872019Synonym Infarction of heart

SCTID: 37441018Synonym Cardiac infarctionSCTID: 37442013Synonym Heart attack

SCTID: 37443015

Fully Specified Name

Myocardial infarction (disorder)SCTID: 751689013

Preferred term Myocardial infarctionSCTID: 37436014

MyocardialinfarctionSCTID: 22298006

Injury ofanatomical site

SCTID: 123397009

Structural disorder of heart

SCTID: 128599005

Myocardialdisease

SCTID: 57809008

Is a

Is a

Is a

MyocardiumstructureSCTID: 74281007

Finding siteInfarctSCTID: 55641003

Associated morphology

Relationships• Links concepts within SNOMED CT• Ensures unambiguous meaning • Create hierarchies which aid navigation and retrieval

Key principles/ Traps for new players

Consider the user interface carefully:◦Don’t show Fully Specified Names to

users They’re intended to provide a

unambiguous reference point for computability

They are not worded in a way clinicians speak

◦Do choose a preferred term

Fully specified name

Preferred term (Australia)

Amebic appendicitis (disorder)

Amoebic appendicitis

US Spelling

Semantic tag:• indicates hierarchy• not needed at

clinical level

Unambiguous Reference Point

Key principles/ Traps for new players

Consider the user interface carefully:◦Don’t show all of SNOMED CT in a drop

down list (too many terms!)◦Unless you have tools to assist

searching ◦Do use Reference sets to assist

implementation: Reduce the complexity for the user Speed identification of the correct

term

Problem/diagnosis : Select term

SNOMED CT in Drop down list without any parameters implemented

Problem/diagnosis : Appendi

Improved searching – limited to clinical finding hierarchy

Could be further improved through Refset development

Key principles/ Traps for new players

Reference sets Do require maintenance Therefore:

◦Do use NEHTA reference sets wherever possible (because NEHTA maintain them!)

◦Do use the hierarchies of SNOMED CT to guide creation of RefSets wherever possible

◦ Recognise that if you pick ad hoc terms across hierarchies you will need to manually maintain the list

◦ Sometimes there is no choice – eg. allergies – but there is a cost

Key principles/ Traps for new players

Minimise mapping and data translation:◦There is a safety risk introduced every

time the clinician’s language is translated (Chinese whispers…)

If you do need to map or translate:◦Do keep the original wording/ data entry

as well as the mapped equivalent

Key principles/ Traps for new players

Trap for new players:◦Synonyms may be found in the wrong

hierarchy (different meaning)◦This is why when translating SNOMED CT

translators look at the words within the hierarchy to establish true meaning

◦However, this trap is not just for translators, but also when mapping or creating reference sets.

Is it worth the effort? Even simple use of SNOMED as a flat code

list can add value:◦Allows meaningful exchange of data◦Both end-points can cross-reference to a

standard unambiguous definition◦Simple decision support can be enabled

For example – US Centre for Disease Control, HITSP

and NHS all publish simple lists

Is it worth the effort?

But for those up to the challenge, more advanced use of SNOMED CT offers further potential value

Is it worth the effort?

Ability to Exchange data knowing it can be explicitly and accurately interpreted

Ability to improve data quality:◦More structured data entry◦Agreed constraints can be applied

Is it worth the effort?

Ability to run externally developed queries:◦ For example:

Automatically run mandatory reporting Identify at-risk populations Identify cohorts for clinical trials Trigger presentation of evidence based guidelines when

first releasedNote Kaiser Permanente have a central area which

develop queries/ scripts which are then distributed throughout the organisation

Is it worth the effort?

Ability to utilise external decision support engines:◦Already happening in medicines area◦Opportunity for improved decision

support applications in other areas

Ability to contribute to PCEHR

Is it worth the effort?

Ultimate aim is improving health outcomes and patient safety:◦Through better sharing information◦Ensuring accuracy of information◦Identifying those at risk

Clinical Terminology is essential

Perhaps speaking to the converted, but unless we can agree and implement consistent terminology we will never achieve the goal of better information sharing….

We’ll just be sharing data….