Transcript The Future of NDC: The HL7 Perspective

The Future of NDC:
The HL7 Perspective
James J. Cimino, M.D.
Co-chair, HL7 Vocabulary Technical Committee
Departments of Medicine and Medical Informatics
Columbia University College of Physicians and Surgeons
Outline
• HL7’s Needs
• Desiderata
– Summary of 10+ years of research on
controlled medical terminologies
– Presented at IMIA Working Group 6,
Jacksonville, FL, 1997
• NDC and the Desiderata
• HL7’s Perspective of NDC
HL7 Needs Drug Codes to...
…transfer medication orders from an order
entry system to a pharmacy
…aggregate data from multiple sources
…serves as grist for decision support engines
…just about anything else you can imagine
Drug Model Hierarchy
Packages
Medications
Drug Class
Chemicals
International
Package Identifiers
is-a
Not-Fully-Specified Drug
Ingredient
Class
is-a
Country-Specific
Packaged Product
Clinical Drug
is-a
Ingredient
is-a
is-a
Trademark Drug
is-a
Manufactured
Components
is-a
Composite
Clinical Drug
is-a
Composite
Trademark Drug
Drug Model Hierarchy
Packages
Medications
Drug Class
Chemicals
International
Package Identifiers
is-a
Not-Fully-Specified Drug
Ingredient
Class
is-a
Country-Specific
Packaged Product
Clinical Drug
is-a
Ingredient
is-a
is-a
Trademark Drug
is-a
Manufactured
Components
is-a
Composite
Clinical Drug
is-a
Composite
Trademark Drug
Clinical Drugs
• Dosage form
• Active ingredients
– Chemical
– Form Strength
• Strength amount
• Strength units
• Volume
• Volume units
Content
• Needs to be complete
• Needs to be up-to-date
Concept Orientation
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Unique identifiers associated with meaning
Name can change; meaning cannot
Nonredundant
Unambiguous
Codes can’t be reused
Concept Permanence
• Meaning doesn’t change
• Never deleted
Nonsemantic Identifiers
• Don’t use names
• Don’t use mnemonics
• Don’t use hierarchical codes
Polyhierarchy
• Multiple classes for terms
• Multiple views
Polyhierarchy
Tablet
Nonsteroidal
Anti-inflammatory
Medication
Opiate
Analgesic
Aspirin
Preparations
Codeine
Preparations
Aspirin 325/
Codeine 30mg
Tablet
Empirin #3
Glaxo
Wellcome
Products
Formal Definitions
• Avoid misunderstanding of meaning
• Allow detection of ambiguity and redundancy
• Support multiple classification
Formal Definitions
(Empirin #3:
(Ingredients:
( (Ingredient Aspirin) (Strength “325”) (Units milligrams) )
( (Ingredient Codeine) (Strength “30”) (Units milligrams) )
(Form: Tablet)
(Manufacturer: Glaxo Wellcome) )
NEC
Reject “Not Elsewhere Classified”
• Ambiguous (e.g., “Other Antibiotics”)
• Semantic drift thwarts concept permanence
Multiple Granularities
• Different users need different abstractions
Multiple Granularities
Nonsteroidal
Anti-inflammatory
Medication
Aspirin
Preparations
Aspirin 325/
Codeine 30mg
Tablet
Empirin #3
Graceful Evolution
• Support:
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Simple addition
Refinement
Minor name changes
Precoordination
Disambiguation
Obsolescence
Discovered redundancy
• Avoid:
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Redundancy
Major name changes
Code reuse
Changed codes
NDC and the Desiderata
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Content - timeliness and comprehensiveness
Concept orientation - done
Concept permanance - needs work
Nonsemantic identifiers - worst of both worlds
Polyhierarchy - may be beyond purview of FDA
Formal definitions - easily accomplished
Reject “NEC” - done (watch out for hierarchies)
Multiple granularities - as per polyhierarchy
Graceful evolution - editorial policy needed
HL7’s Perspective
• Need unique identifiers for:
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Clinical (orderable) products
Dispensable products
Classes
Drug forms
Delivery routes
• Need all these in a timely, high-quality form
• Not all need come from FDA