Managing SNOMED in your system.Managing SNOMED in your system.2nd AAHA Software Vendors Summit – April 21, 2009

Nomenclature TasksNomenclature Tasks• Install nomenclature(s)• Subsets reduce SNOMED’s volume

• Displaying preferred descriptions• System wide, even user specific

• Requests from users for concept addition• Install Updates (ongoing and indefinitely)• Message processing• Data sharing only (multiple practices)

• Query Interface for data retrieval

Distribution formatDistribution format• XML using SNOMED’s schema• Current version• Sample subset• Complete concept

• Separate update distribution format can be developed.

Find and display descriptions (terms)Find and display descriptions (terms)

• This task has not changed.• Descriptions retain the essence of AAHA

Diagnostic terms

• Index and search descriptions

• “Select” records concept ID• Description ID is optional

Concept AdditionConcept Addition• Users WILL discover concepts that are

not present in the nomenclature• Licensed users can make requests to

SNOMED directly• Channels have been established for

“timely addition”.• Inadequate staff re: veterinary content

Concept AdditionConcept Addition• When we (VTSL) receive a request for

concept addition:• We confirm that the concept is really missing

• Often there is a synonym present• Requested “description” can be added

• We prepare a SNOMED-style definition for the concept and forward info to SNOMED.

• Concepts are added to the nomenclature by a veterinarian on SNOMED staff

Managing concept requestsManaging concept requests• Veterinarian should be able to “request” additions

without interfering with work flow.• Vendors should not need to hire terminologist(s).• Communications between veterinarian and

terminologists should be automated.• Requires “placeholders” in medical records system.• Should be FULLY AUTOMATED (requires no Vendor

participation in terminology give-and-take).

Managing concept requestsManaging concept requests• User can’t find the thing they want to say• One click to “let me just type it”• Save of veterinarians phrase sends (parse-able)

message to VTSL webservice• VTSL replies with:

• Please provide more information. What is this thing you’re trying to say? (we need conversation ability)

• Here’s your new description for existing concept OR• Here’s a new concept and description

Post-coordination (partial alternative to requests for new content)Post-coordination (partial alternative to requests for new content)

• What is post-coordination?• Create a new concept by adding specificity to and existing

SNOMED concept.

• Source has: • “Acute pasteurella pneumonia”

• Target (SNOMED) has:• “pasteurella pneumonia”

• Create:• Pasteurella pneumonia + has course = acute

Post-coordinationPost-coordination

• Where do you put your new creation?• Extend the concepts table (1 new)

• Identifier outside of SNOMED itself (namespace mechanism)

• Extend the “relationships table”• An extension (not part of core)• Processed as if it is part of the original table.

Pasteurella pneumonia + has course = acute

Nomenclature UpdatesNomenclature Updates• New version of SNOMED scheduled for every 6 months.

• Expect change rate to decline with time

• We update our systems within 1 or two weeks of release.• VTSL creates content in extension. Updates can be AS

NEEDED.• To date we’ve negotiated ONE update formalism. It is

specialized to NAHLN (which needs subsets from additional nomenclatures).

Nomenclature UpdatesNomenclature Updates• Retired Concepts• Concept “referral” mechanism

• New Concepts

• Retired Descriptions

• New Descriptions

• New relationships

QueriesQueries• Query full copy of SNOMED• Queries based on description have highest

yield.• Indexes

• Query portion that has been recorded?

Display Concept “definition”Display Concept “definition”

SELECT ConceptID2FROM RelationshipsTableWHERE ConceptID1 = (TargetConceptID)AND RelationshipsType =116680003;

TargetConceptID

(Gather IsA parents)

SELECT ConceptID2, RelationshipType, RelationshipsGroupFROM RelationshipsTableWHERE ConceptID1 = (TargetConceptID)AND CharacteristicType = 0 AND NOT RelationshipsType =116680003

(Gather non isa Children)

(Output)

ISA relationships always defining116680003 = “ISA”

Group by RelationshipsGroupCharacteristicType =0 is defining

“List” a SNOMED “definition”

Recursion for gathering all descendants of a concept.

• Build subsets• breeds, species• all disorders• all cardiovascular disorders• etc.

• Query for concept and all its specializations

• everything that “ISA” respiratory disease.

ConceptID

SELECT Distinct ConceptID1FROM RelationshipsTableWHERE RelationshipsType =116680003 AND ConceptID2 IN (NewChildlist);

SET NewChildList = ConceptID

APPEND returns from query to s

SET NewChildList = Returns from query

Output Childlist

Returns? – YesNo

Variations on this query:

Simple subtypes of epilepsy are all specializations of epilepsy•Benign focal epilepsy•Parietal lobe epilepsy

Search for all concepts that are defined by the presence of seizuresreturns concepts that are seizure disorders but not epilepsies.

•Benign focal epilepsy•Seizures due to metabolic disorder