December 10, 2002Eric Rose, MD1 Home-Grown Coding Systems—A Critical Step in EMR Implementation Eric Rose, MD Associate Director for Clinical Informatics Information Systems Department University of Washington Physicians Network

December 10, 2002Eric Rose, MD2 SUMMARY Implementation of any EMR (including vendor-supplied) requires the that the user institution create coding systems This can be done well or badly It matters

December 10, 2002Eric Rose, MD3 Some definitions Concept: an idea encompassing a class of objects ("unit of knowledge created by a unique combination of characteristics"-ISO) Term: A word denoting a concept Terminology/Controlled Vocabulary/Ontology: a set of terms pertaining to a given domain, not necessarily with any structure Nomenclature: A terminology “structured systematically according to pre-established naming rules” (ISO)

December 10, 2002Eric Rose, MD4 Coding system: A terminology + context-free symbolic codes for each term Classification/taxonomy: A terminology system + specified relationships between terms (“concept system”-ISO ) Some definitions (cont’d)

December 10, 2002Eric Rose, MD5 What is a coding system and what does it do? Represents in a standardized fashion Groups Separates Abbreviates Facilitates automated data- processing & transmittal

December 10, 2002Eric Rose, MD6 Types of coding systems Simple, 1-1 (CA, NY, TX) Categorical (record store bins) Hierarchical (homo sapiens) Multiaxial (Dewey-decimal, SNOMED)

December 10, 2002Eric Rose, MD7 What does this have to do with EMR Implementation?

December 10, 2002Eric Rose, MD8 LOINC SNOMED CT ICD-10 CPT ICD-9-CM READ NCPDP NDC NANDA THE UNIVERSE OF CONCEPTS

December 10, 2002Eric Rose, MD9 What does this have to do with EMR Implementation? Most EMR’s allow customized choices for various database items Each one of these is a small coding system

December 10, 2002Eric Rose, MD10 If developed carefully, home-grown coding systems facilitate:  Intuitive data entry  Interpretable individual patient level  Usable data at population level  Usable data for automated decision-support systems  Data that is shareable with other systems What does this have to do with EMR Implementation? (cont’d)

December 10, 2002Eric Rose, MD11 Examples of mini-coding systems you might need to create Disease Categories for Family History Reason for Visit Allergic Reaction Type Delivery Outcome Anesthesia Type for Surgery Source of Diagnostic Specimens Ethnic Group Marital Status

December 10, 2002Eric Rose, MD12 What makes a coding system good? Completeness Nonredundancy Clarity Stability Granularity appropriate to use or flexible Evolutionary (Adapted from Cimino, 1998; Chute et al., 1998)

December 10, 2002Eric Rose, MD13 Completeness There should be a term for any possible situation

December 10, 2002Eric Rose, MD14 Completeness—Example Reason for Medication Discontinuation Allergic response Alternate therapy Availability Cost of medication Discontinued by another Health Care Provider Discontinued by patient Dose adjustment Duplicate Error Ineffective NON Covered Medication Paradoxical response Pregnancy Prescription never filled Reorder Resistant Organism Side effects Therapy completed What if medication was never taken by patient? No way to denote that!

December 10, 2002Eric Rose, MD15 Nonredundancy There should be only one term for any given situation

December 10, 2002Eric Rose, MD16 Nonredundancy-Example Next of Kin-Relationship to patient Domestic Partner Life Partner Partner Significant Other

December 10, 2002Eric Rose, MD17 Clarity The categories in your coding system should be unambiguous to all users

December 10, 2002Eric Rose, MD18 Clarity-Examples Family Medical History category “Blood Disease,” “Anesthesia” Medication reason-for-d/c “Alternative Therapy,” “Error”

December 10, 2002Eric Rose, MD19 Stability Once defined, the meaning of a code must not be changed, though it may be inactivated so it is not applied to any new cases

December 10, 2002Eric Rose, MD20 Appropriate or Flexible Granularity Granularity = Level of detail described by the coding system, i.e. “fineness” of categorization Low granularity = Few, broad categories High granularity = Many, narrow categories

December 10, 2002Eric Rose, MD21 Appropriate Granularity-Examples Family History categories “Alcohol dependency,” “Drug dependency”—It is sufficient to just have one category for “Chemical Dependency” “Heart disease”-Not granular enough to meet needs of risk assessment for coronary disease

December 10, 2002Eric Rose, MD22 Evolutionary Coding system development is an ongoing process, requiring addition of new categories and inactivation of old ones to keep the system congruent with prevailing ideas. Example = Family History category, “Venous Thrombosis”

December 10, 2002Eric Rose, MD23 Guiding principles CENTRALIZE control of the coding system Keep your lists SHORT Respond PROMPTLY to user requests for additions and explain rationale when it’s not appropriate to meet the request Design for the future including new user types & interfaces Careful with “Other”

December 10, 2002Eric Rose, MD24 For further reading: Bakken S et al. Toward Vocabulary Domain Specifications for Health Level 7-coded Data Elements. JAMIA 7: , Cimino JJ. Desiderata for controlled medical vocabularies in the twenty-first century. Methods Inf Med Nov;37(4-5): Chute CG. Cohn SP. Campbell JR. A framework for comprehensive health terminology systems in the United States. JAMIA 5(6):503-10, 1998 Nov-Dec. ISO :2000. Terminology Work- Vocabulary-Part 1: Theory and Application