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

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

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

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

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

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

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

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?

Gunshot in atrium.

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

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

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

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

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

NEC

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

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