Archetypes in HL7 2.x

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Archetypes in HL7 2.x
Snomed-Gello-HL7 More than a pick
List Andrew McIntyre Medical-Objects http//
www.medical-objects.com.au/ 11th HL7 Australia
Conference, 13th December 2006 Melbourne,
Australia
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Terminology is for Computers

• Humans understand text pretty well
• Computers are pretty hopeless at it
• Much better with codes
• Can manage much more in memory
• Are obsessive and tireless
• A path to decision support
• Snomed-CT is for computers

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Focus Concept

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Attributes Post Co-Ordination

• Attributes are defined by model
• Vary depending on type of statement
• Qualify concepts

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Context of Statements

• Past History
• Family History
• Planned
• Possible etc
• Every statement needs context
• Default context
• Known present
• About patient
• Current or specified

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Context added to statements

• Removes much ambiguity

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Context Example

• Procedure Context
• These are Values

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Snomed CT

• Abstract logical Model under development
• Conflicts/overlaps with some HL7 V3 structures
• HL7 V2 has administrative models
• Limited clinical model (Medication mainly)
• It is possible to represent Snomed-CT Abstract
  Logical Model in HL7 V2
• Requires tree structures within groups of OBX
  segments

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Some detail

• Nested NameValue pairs
• Consistent with Snomed-CT Model
• HL7 V2.x can encode this

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In HL7 V2.3.1

• OBX segments are designed to carry NAMEVALUE
  pairs with date
• Dotted Sub-ID for structure
• Relatively simple display rules linear display
  is possible

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Snomed-CT Model

• Snomed Grammar

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Multiple Inheritance Model

• Eg Cholecystectomy

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Gello Statement
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Requires Patient Model
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Gello Can Exploit This
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Gello can validate
Need to ensure statements are valid wrt Model
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Snomed Constraints
Archetype base Constraints restricts user to
correct terms
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Summary

• Snomed-CT allows high level computability
• Must follow Snomed-CT Model
• Needs more structure
• Archetypes in HL7 V2 can do this
• Archetypes can constraint choices
• Gello, vEMR and Terminology Server allow
  computable medical Records
• Standards needed for interoperability of records