1. The Needs for Coding and Classification Systems
Multiple needs for controlled vocabulary
Capturing clinical data for multiple purposes
(In)adequacy of current systems
Some desired characteristics
A model for the future

2. Multiple Needs Electronic record keeping Decision support Billing
Reviewing patient data
Alerts and reminders
Access to on-line information resources
Billing
Management
Case management QA
Clinical research
Epidemiology

3. Capturing Clinical Data for Multiple Purposes: Now
Recode Patient Data
Collect Patient Data
Collect Patient Data
Financial Database
Clinical Repository
Research Database

4. Capturing Clinical Data for Multiple Purposes: Future
Recode Patient Data
Collect Patient Data
Collect Patient Data
Financial Database
Clinical Repository
Research Database

5. Some Desired Characteristics
Synonymy
Concept-oriented (one term = one meaning)
Clear semantics
No limits on number, depth, breadth of terms
Multiple hierarchies
Multiple granularity
Sensible compositionality
Interchangeable constructs

6. Synonymy Many names for the same concept is good...
... but they must be recognized as synonyms
This is easy

7. Concept-Oriented: One Term = One Meaning)
No ambiguity
Concept permanence
Easy to say, not so easy to do

8. Clear Semantics What does the term really mean?
How is it meant to be used?
Example: Penicillin
The chemical?
The pill?
Example: Gunshot
The act?
The injury?

9. Gunshot in atrium.

10. No Limits on: Number, Depth, Breadth of Terms
No limits imposed by coding scheme
No limits posed by computer limitations

11. Multiple Hierarchies Medicine is multihierarchic
Organ system vs. etiology
Macro vs. micro
Each user of data will want their own view

12. Multiple Granularity Clinical users will want fine-grained terms
Epidemiologists and payors will want coarse-grained terms
Decision support and research will want something in between

13. Sensible Compositionality
Users will always need to record at a finer level of detail
Need to be able to combine coded terms
Need rules for combining them
Need to be able to recognize synonymy

14. Interchangeable Constructs
Pneumonia
Finding
Left Lower Lobe
Left Lower Lobe Pneumonia
is-a: Pneumonia
has-site: Left Lower Lobe
participates-in: Finding

15. NEC

16. (In)adequacy of Current Systems
ICD9-CM SNOMED CPT4 Read Gabrieli - + - +
+/-
Synonymy
Concept-oriented
Clear semantics
No limits
Multhierarchies
Granularity
Compositionality
Interchangeable - + - + ? - - - ? ? - - + + - - - - + - - + - + - - + - + - - - - - -

17. A Model for the Future Meaningless codes Semantic network Grammar
Definitional information
Reject "Other" terms