1. 11th HL7 Australia Conference, 13th December 2006
Archetypes in HL7 2.x
Snomed-Gello-HL7
More than a pick List
Andrew McIntyre
Medical-Objects
11th HL7 Australia Conference, 13th December 2006
Melbourne, Australia

2. 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

3. Focus Concept

4. Attributes = Post Co-Ordination
Attributes are defined by model
Vary depending on type of statement
Qualify concepts

5. Context of Statements Past History Family History Planned Possible etc
Every statement needs context
Default context
Known present
About patient
Current or specified

6. Context added to statements
Removes much ambiguity

7. Context Example
Procedure Context
These are “Values”

8. 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

9. Some detail Nested Name=Value pairs Consistent with Snomed-CT Model
HL7 V2.x can encode this

10. In HL7 V2.3.1
OBX segments are designed to carry NAME=VALUE pairs with date
Dotted Sub-ID for structure
Relatively simple display rules –linear display is possible

11. Snomed-CT Model
Snomed Grammar

12. Multiple Inheritance Model
Eg Cholecystectomy

13. Gello Statement

14. Requires Patient Model

15. Gello Can Exploit This

16. Gello can validate
Need to ensure statements are valid wrt Model

17. Snomed Constraints Archetype base Constraints
restricts user to correct terms

18. 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