Transcript VA National Drug File Reference Terminology

Building a National Medication
Reference Terminology:
VA Experience with NDF-RT
Presented to HL7 Government SIG By Steven Brown
& Michael Lincoln, Department of Veterans Affairs
In collaboration with NLM, FDA, NCI and Apelon
Why a Common Drug Reference
Terminology?
• Improve use of drug information by single
systems
• Improve sharing of drug information by
adding semantic understanding to the syntax
defined by HL7 messaging between systems
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VA National Drug File (NDF)
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Centrally maintained file of drug products
Distributed to 128 VA Medical Centers
Incorporated into VistA Pharmacy Applications
~ 80,000 Entries
Maintained and used via “M Globals”
– VA Product File
– VA Active Ingredient File
• More than a decade of experience…
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NDF Uses Within VA
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National standard listing
Local formularies mapped to NDF standard
Interaction and Order Checking
Consolidated Mail Outpatient Pharmacy
– > 7 sites, 57 million prescriptions/year
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NDF Product File
• Product Names
– AMOXICILLIN 250MG/CLAVULANATE K
125MG TAB
• Form, Strength, Product Identifier
• Linked to: VA Drug Class :
– AM052 “penicillins, amino derivatives”
• Linked to: Active Ingredients
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NDF - Issues
• Maintenance
– 4000 NDC level edits per month
– Done largely by hand
• Mapping local formularies to NDF
– Manual process
– Required for CMOP
• Decision Support – class based
– CN101 “Opioid Analgesics” vs. CN103 “Non-opioid
analgesics”
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NDF Reference Terminology (RT)
• Enterprise Architecture project
• Goal – to evaluate the use of modern
terminology techniques to increase
functionality, improve quality and decrease
costs
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Rossi Mori
First Generation Terminology
• Traditional Paper-Based Terminological
Systems with lists of phrases and codes.
– E.g. ICD9, CPT
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Rossi Mori
Second Generation Terminology
• Second Generation Terminology
– Compositional terminological systems built
according to a categorical structure and a crossthesaurus with predefined values for each
category.
– E.g. LOINC
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Rossi Mori
Third Generation Terminology
• Reference Terminology –
– A terminology where each term has a formal
definition designed for data aggregation and
retrieval.
– Formal terminological systems represent
concepts with symbols and rules that create a
computable structured and coded system
– e.g. SNOMED RT, NDF RT
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Advantages of Formal
Terminology
• Computer-based tools
– Reduced Maintenance Costs
• 90% reduction in MED Maintenance effort
– Reduced Mapping Effort
• 60% automated matches to formalized version of
LOINC
• Comparable Data
• Supports Aggregation
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Reference Terminology Creation
• Create a model of use case-based
definitional attributes
• Create a reference hierarchy for each
definitional attribute
• Define concepts using terms from reference
hierarchies
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Simplified NDF RT Model
Structural ID
Strengths
Dose Forms
Route of Adm.
(HL-7)
Chemical Structure
Database Links
DKB Ids, CUIs, Mesh
Active Ingredients
Mechanism of Action
Clinical Drug
Therapeutic Use
Pharmacokinetics
National Drug
Codes (NDCs)
Identity Key
Gray = Chemical
Green = Clinical
Pink = Commercial
Blue = Functional
Yellow = External
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Sample MoA Hierarchy
Receptor Interactions
Channel
Agents
Transporter
Agents
ABC
Transporters
Enzyme
Interactions
Organic Ion
Transporters
LST-1
Sialin
Transporter
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Sample Definition
AMOXICILLIN 250MG/CLAVULANATE K 125MG
TAB
– Has_form: tablet
– Has_active_ingredient: Amoxicillin
• Has_strength 250 mg
• Has_MoA: cell wall synthesis disruption
– Has_active_ingredient: Clavulanate
• Has_strength 125mg
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NDF RT Progress to Date
• NDF in terminology development tool
• Model Created
• Reference Taxonomies
– Done: Route, Form, Strength, Structure
– Under development : MoA, Physiologic Effect,
Therapeutic Intent and Pharmacokinetics
• Concept Definition
– Algorithmic initialization
– Human review
• Input from NLM, HL7, FDA, NCI, Apelon
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NDF RT – Next Steps
• Sample Applications demonstrating value
• Expand Project beyond VA
– NLM, FDA, NCI, Regenstrief, ???
– Freely available to others for reuse
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NDF RT Model
Chemical Structure
Class
Database Links
Active Ingredients
Mechanism of Action
Clinical Drug
Therapeutic Use
Finished Dosage Form
Pharmacokinetics
DKB Ids, CUIs
Structural ID
Strengths
Dose Forms
Route of Adm.
(HL-7)
Appearance
Brand Names
National Drug
Codes (NDCs)
Product
Packaged Product
Kit
Identity Key
Gray = Chemical
Green = Clinical
Purple = Commercial
Blue = Functional 18
Yellow = External