1. Controlled Medical Nomenclature for NAHLN
January 2005
Las Vegas, NV

2. Qualifications There’s “retentive” – if that’s not enough:
There’s “anal retentive” – if that’s not enough:
There’s “retentive enough to create and maintain a nomenclature”

3. Lists of words… Nomenclature Vocabulary Classification
The system or set of names for things, etc., commonly employed by a person or community (Petchamp, SNVDO, SNOMED)
Vocabulary
A collection or list of words with explanations of their meanings (SNOMED)
Classification
The result of classifying; a systematic distribution, allocation, or arrangement, in a class or classes; esp. of things which form the subject-matter of a science or of a methodic inquiry. (SNOMED)

4. What do we need? Nomenclature ONLY Vocabulary / Classification
Provides a simple list for data entry
Vocabulary / Classification
We can be CERTAIN that the “term” (description in SNOMED) means what we think it means.
We can develop rules that allow us to combine concepts to express ideas more complicated than those contained in the nomenclature.
We can use the knowledge base supported by the vocabulary/classification to search, retrieve and analyze our data.

5. NAHLN Nomenclature needs
Is controlled nomenclature (1 or more) essential – YES
Is LOINC essential – Yes (or something close)
Is SNOMED essential – NO, but you need standard microorganisms, breed/species, etc.
Can SNOMED provide what’s needed outside of laboratory tests - YES

6. Why a controlled nomenclature?
Aggregation of text-based content from multiple sources
Multiple individuals
Multiple institutions
Any time you rely on a computer to manipulate language and “meaning” is critical.
Procedures list (for billing)

7. Why a controlled vocabulary / nomenclature?
Bovine respiratory disease complex = Shipping fever = BRDC
How does one automate recognition of the synonymy?

8. Why did “we” pick SNOMED?
A shared nomenclature must be maintained.
SNOMED is the ONLY actively maintained nomenclature that has veterinary content.
AVMA had a long-term investment
Veterinary medicine CANNOT afford:
To build it’s own competent nomenclature
To continue to live without a competent nomenclature

9. Characteristics of a controlled vocabulary / nomenclature.
Cimino, JJ. Desiderata for Controlled Medical Vocabularies in the Twenty-First Century Methods of Information in Medicine Nov, 37(4-5):
THE Review of ideal characteristics of a controlled medical vocabulary / nomenclature.
Perhaps the best READING review of medical vocabulary / nomenclature available.

10. Content, content, content
First criticism of ANY nomenclature (by users) is lack of content

11. Content, content, content
Approaches
Enumerate all possible concepts (simple and complex)
Pneumonia
Pneumonia of left lung
Pneumonia of left caudal lung
This nomenclature will grow quickly. It will get VERY large VERY fast.

12. Content, content, content
Approaches
Enumerate all possible concepts (simple and complex)
Provide all necessary “atoms,” create effective syntax, “teach” the syntax to users (or systems).
Pneumonia
Left lung
Left Caudal lung
Pneumonia, body part (left lung)
Pneumonia, body part (left caudal lung)
Probably the theoretical ideal. I have not the first idea how!

13. Content, content, content
Approaches
Enumerate all possible concepts (simple and complex)
Provide all necessary “atoms,” create effective syntax, “teach” the syntax to users (or systems).
Drastically limit the scope of the nomenclature.
May actually improve usability of the nomenclature for a limited purpose, however:
The next project and the next interaction require development of a new nomenclature
Connections between projects require “mapping”.
Users will not be happy.
Might be easier to build and use a large single nomenclature.

14. Concept Orientation Concept – an embodiment of a particular meaning
Concepts must correspond to at least one meaning (non-vagueness)
Concepts must correspond to no more than one meaning (non-ambiguity)
Meanings correspond to no more than one concept (non-redundancy)

15. Concept permanence
Once created, the meaning of a concept is inviolable.
Concept identifiers can NEVER be reused.
Contributes to stability of legacy information.

16. Non-semantic identifier
Unique name
Using the name inhibits (prohibits?) improvements in concept “name”
Harder to cope with synonymy.
Hierarchical designators (codes with meaning) inhibit classification
Monohierarchies provide inadequate classification capability for retrieval purposes.
Polyhierarchies cannot be supported.
(A concept can’t be in its multiple logical locations).

17. Polyhierarchies Medical concepts often classified in multiple ways
Acute bacterial pneumonia
It is a bacterial (infectious) disease
It is a pulmonary disease
It is an inflammatory condition
It is an acute condition

18. Formal definitions
Collection of relationships to other concepts in the vocabulary
Acute Bacterial pneumonia
Causative agent = bacteria
Has location = lung
Has morphology = inflammation
Has course = acute

19. Reject “not elsewhere classified”
The fundamental problem is “meaning drift”
Example
Year one nomenclature has
Pneumonia
Bronchitis
Respiratory disease NEC

20. Reject “not elsewhere classified”
The fundamental problem is “meaning drift”
Example
Year TWO the nomenclature has
Pneumonia
Bronchitis
Tracheobronchitis
Respiratory disease NEC
Last year tracheobronchitis was “respiratory disease, NEC”

21. Reject “not elsewhere classified” (NEC)
NEC ≠ NOS (Not Otherwise Specified)
NOS = “I’ve said all I’m going to say”.
NOS is not considered to be inappropriate.
Current preference is to exclude NOS. The concept means what it means, no more no less.

22. Multiple granularities
A large standardizing nomenclature (like SNOMED) must provide concepts at an appropriate level of detail for every user class.
Not an issue with a purpose-built nomenclature.

23. Recognize Context
Must provide an ability to distinguish between uses of the concept…
Patient has acute bacterial pneumonia
Patient has history of acute bacterial pneumonia
Patients littermate died of acute bacterial pneumonia
System design and perhaps the message system should cope with acquiring context
Nomenclature may be required to cope with context in messages, or may provide context concepts for the message.

24. Evolve Gracefully
A nomenclature must have a strategy for coping with new content.
The bane of home grown nomenclatures
(Who’s looking after your list of concepts?)
Nomenclature maintenance is not everyone’s cup of tea.
A controlled nomenclature serves as an arbiter of sorts.
A nomenclature used by more than one organization (d-lab) must have update and sharing mechanisms in place.

25. Recognize redundancy Redundancy must be avoided in the concept list
Redundancy must be provided for using a synonym mechanism.
Egos and dispersed training insure that there exist multiple ways to say almost anything.
They’re still talkin’ about the same thing.

26. SNOMED history / future
SNOMED III
SNOMED RT
SNOMED CT
SNOP
SNOMED
SNOVET
1965
2000
Reduce storage size
Reduce Storage size
No longer relevant
Categorize information
Multiple code-based hierarchies
Poly-hierarchical categorization
Pathology content
“All Medicine” Veterinary content separate, then integrated
Integrated content
“Computability” for retrieval.
Natural language, artificial intelligence, decision support

27. Development history SNOP SNOMED SNOVET SNOMED III SNOMED RT SNOMED CT
Morphologies
SNOMED
Morphologies, Etiologies, Locations
SNOVET
Same structure as SNOMED
Mix of existing SNOMED, additional veterinary content
SNOMED III
Disorders, Morphology, Living organisms, social context
Veterinary content re-integrated
SNOMED RT
Logic based approach to SNOMED. Axes became hierarchies. Most significantly, the poly-hierarchic approach to classification.
SNOMED CT
SNOMED RT on steroids. Post merger with CTv3.

28. SNOMED III (3.5) Axes A – Physical agents C – Chemicals D – Disease
F – Biological function
G – General qualifiers
J - Jobs
L – Living organisms
M – Morphology
P – Procedures
S – Social context
T – Topography
X – Pharmaceutical companies

29. SNOMED CT Disease Finding / observation / clinical history Procedure
Body structure normal and abnormal
Organism
Physical Force
Substance
Specimen
Social Context
Attributes
Context dependent categories
Physical object
Events
Environments and geographical location
Observable entity
Qualifier value
Staging and Scales

30. Complaints about SNOMED
It’s too…
Big
Complicated
Expensive
Yes but…
We can make it smaller (sort of), and use small pieces (for most purposes).
Use it in simple and straightforward ways
But nothin, it’s a bit expensive.
Not the license fees, the cost of making it work.

31. Is the expense worth it? IF the long-range goal is useful…
The selected standards adhere to design specifications that have developed through hard experience in the medical profession.
Essential / desirable features have been documented.
The selected standards represent extraordinary functionality, produced and maintained at great cost to the medical profession.
We can leverage these standards for 10¢ / $1.00

32. Bovine reportable disease system.
Bovine breeds
Bovine “occupation” and husbandry concepts
Brief list of reportable diseases
Lab tests that support disease list
Place to put the concepts in the message structures
Lab to network

33. Bovine medical record Bovine Breeds
Bovine lab tests, all not just reportable
All applicable disorders, findings, procedures
Message structures
lab to clinic
clinic to lab
clinic to clinic

34. Subsets of standards Bovine Reportable Bovine disorders
SNOMED-CT, HL-7,
LOINC
Bovine Reportable
Mixed practice
Bovine practice
Bovine disorders

35. Disease reporting system
LOINC1
SNOMED1
HL72
WNV
Rabies
FMD
1 = three independent subsets
2 = one subset of necessary messages