MDF99 Vocabulary Chapter HL7 Working Group Meetings April 26, 1999 Toronto, Canada Stan Huff - [email protected]

MDF99 Vocabulary Chapter

HL7 Working Group Meetings

April 26, 1999

Toronto, CanadaStan Huff - [email protected]

http://www.hl7.org

3/18/1999 2© 1999, Health Level Seven, Inc.

Message Development Framework

• Description of how to develop Version 3 Messages

• 1999 is the first time a vocabulary chapter has been included

• Focuses on processes and methods for producing ballotable Version 3 messages

• Complete draft document is available from the Duke web site

• Final 1999 document will be available by the last week of May


Outline of Vocabulary Chapter

• Vocabulary domains

• Structure of coded elements in messages

• The general process of maintaining domain specifications

• Good vocabulary practices

• Use of external terminologies in HL7 standards (Keith Campbell)

• The use of local vocabularies in coded elements

• HL7 vocabulary and the UMLS Metathesaurus


Vocabulary Domains

• Introduction

• Vocabulary Domains and Vocabulary Domain Specifications

• Vocabulary Domain Constraints– Rules for creating vocabulary domain constraints– The syntax for constraining vocabulary domains in MIMs,

METs, CMETs, HMDs, and clinical templates

• Validating Vocabulary Domain Specifications and Constraints

• The Domain Specification Database


Introduction: Vocabulary domains

• Marital Status– single (never married)– married– divorced– separated

• “Vocabulary” to distinguish from “Subject Domains” in the RIM

• Why Vocabulary Domains?– Increase interoperability– Sharing of data (clinical care, outcomes, research)– Sharing of decision logic


Vocabulary domain

• “The set of all concepts that can be taken as valid values in an instance of a coded field or attribute.”

• Concept - “A unit of thought constituted through abstraction on the basis of characteristics common to a set of objects.” ISO 1087

• Each concept in the domain can represented using a specific vocabulary/terminology


Each coded attribute has a domain specification

Class: Patient

Description: A person who may receive, is receiving, or has received healthcare services.

Associationsis_a_role_of (1,1) :: Personis_source_for (0,n) :: Specimen_sample

Attributesbirth_order_numberbirth_dttm (from Person)gender_cd <Gender, Strength:CWE>


Vocabulary Domain Specification

• One for each coded RIM attribute

• General form:– <domain name, list of domain qualifiers>

• Currently two types of domain qualifiers– Strength (StrengthOfCoding)

• CNE - Coded No Exceptions

• CWE - Coded With Exceptions

– Realm (RealmOfUse)• Universal

• USA?

• Europe?

• Others


Vocabulary Domain Constraint

• Used in MIM, MET, CMET, HMD, Clinical Templates

• Example:– <(Gender - (O,HL7001,2.3.1,Other), Strength:CNE)>

• General Form– <domain expression, list of qualifiers>

• Three forms for domain expression– Single domain (same as domain specification)– Single code (same as Code Value, V3 Data Type)– Set operation expression

- Union

• - - Difference (sometimes represented as “\”) - Intersection


Validating Specifications and Constraints

• Validation can be time and resource intensive

• May want to do selective validiation– During testing and debugging– During conformance testing– During the creation of each message– During the decoding of each message– Only on some fields– Only when errors occur– Or all of the above


The domain specification database

• There can (and will) be improvements in the table design

• Requirements: (UML model not shown)– Unique, non-sense identifier– Unique textual name– Description/definition– Edit note– Version tracking– Can be specific to a realm of use– Each “leaf” set is from a single vocabulary– Domains can be recursively defined– Set notation will be used to describe relationships


Domain Specification Database Tables

• Composite Domain Definition Table

• Primitive Domain Definition Table

• Primitive Domain Enumeration Table

• LOINC to Domain Linking Table

• Version Tracking Table

• Edit Permissions Table


Composite Domain Definition Table

DomainId

DomainName

Description Realm Expression Status Vin Vout LUDate Who

1 Gender The genderof a person.

Universal Gender A 1 990414 Wayne

5 Race The race ofa person.

USA AmericanIndianOrAlaskaNative Asian

BlackOrAfricanAmerican

NativeHawaiianOrPacificIslander WhiteRace

P 1 2 990414 Dan




NativeHawaiianOrPacificIslander WhiteRace

A 2 990416 Dan

5 Race Race Europe EuropeanRace P 1 990414 Angelo1000 AmericanIndian

OrAlaskaNativeAmericanIndian OrAlaskaNative

Universal AmericanIndian AlaskaNative P 1 990414 Dan

1001 AmericanIndian AmericanIndian

Universal AmericanIndianGroup Apache Arapaho

AssiniboineSioux Caddo CahuillaCaliforniaTribe

CanadianAndLatinAmericanIndian

Chemakuan Cherokee Cheyenne

Chickahominy Chinook Chippewa

ChippewaCree Choctaw Chumash

Comanche Coushatta Creek Cupeno Delaware

P 1 990414 Dan


Composite Domain Definition Table (content)DomainId

DomainName

Description Realm Expression

1 Gender The genderof a person.

Universal Gender




NativeHawaiianOrPacificIslander WhiteRace5 Race The race of

a person.USA AmericanIndianOrAlaskaNative Asian


NativeHawaiianOrPacificIslander WhiteRace5 Race Race Europe EuropeanRace1000 AmericanIndian

OrAlaskaNativeAmericanIndian OrAlaskaNative

Universal AmericanIndian AlaskaNative

1001 AmericanIndian AmericanIndian

Universal AmericanIndianGroup Apache Arapaho

AssiniboineSioux Caddo CahuillaCaliforniaTribe

CanadianAndLatinAmericanIndian

Chemakuan Cherokee Cheyenne

Chickahominy Chinook Chippewa

ChippewaCree Choctaw Chumash

Comanche Coushatta Creek Cupeno Delaware


Composite Domain Definition (version tracking)

DomainId

DomainName

Realm Status Vin Vout LUDate Who

1 Gender Universal A 1 990414 Wayne5 Race USA P 1 2 990414 Dan5 Race USA A 2 990416 Dan5 Race Europe P 1 990414 Angelo1000 AmericanIndian

OrAlaskaNativeUniversal P 1 990414 Dan

1001 AmericanIndian Universal P 1 990414 Dan


Version Tracking Table

Version Date/Time ofEdit

Who Comment

1 199904142200 Dan Created entries for allcomposite race vocabularydomains

2 199904161000 Dan After testing and review,changed the status of the racedomain to active.


Primitive Domain Definition Table

DomainId

Domain Name I or E Code Sys Code SysVer

Expression Status

1 Gender I CR 6 A1 Gender I HL7 2.3.1 A1 Gender E SNI 3.4 ChildrenOf(T-D0A90) A20001 AmericanIndian

OrAlaskaNativeI HL7 2.3.1 A

20002 Asian I HL7 2.3.1 A20003 BlackOrAfrican

AmericanI HL7 2.3.1 A

20004 NativeHawaiianOrPacificIslander

I HL7 2.3.1 A

20005 WhiteRace I HL7 2.3.1 A


Primitive Domain Enumeration Table

DomainId

DomainName

ConceptID

CodeSys

TableID

Code SysVer

Code Description Status

1 Gender 1 CR 0220 6 1 Male A1 Gender 2 CR 0220 6 2 Female A1 Gender 3 CR 0220 6 3 Other (Hermaphrodite) A1 Gender 4 CR 0220 6 4 Transsexual A1 Gender 5 CR 0220 6 9 Not Stated/Unknown A1 Gender 1 HL7 0001 2.3.1 M Male A1 Gender 2 HL7 0001 2.3.1 F Female A1 Gender 3 HL7 0001 2.3.1 O Other A1 Gender 5 HL7 0001 2.3.1 U Unknown A


LOINC to Domain Linking Table

LOINCCode

LOINCVersion

Domain Id Domain Name Status

11882-8 1.0L 1 Gender A


Using the Domain Specification Database

• Look in composite domain table– Use domain name and realm– Find domains in expression– Look up domains found in expression

• Look in primitive domain table– Use domain name or Id, and vocabulary– If “Internal” domain

• Resolve domain to individual elements in domain enumeration table

– If “External” domain• Resolve domain by calling a vocabulary server or by reference to

externally maintained tables


Real World Concept Types

• Code Value

• Code Phrase

• Code Translation

• Concept Descriptor


Code Value (definition)

• value (Character String, conditional)

• code system (code, required)

• code system version (Character String, optional)

• print name (Character String, optional)

• replacement (Character String, conditional)

• Condition: An instance of a code value will contain either a value or a replacement, but not both.


Code Value (example 1)

Patient Blood Type == Code Value {value “F-D1111”,code-system “SMI” -- from a tablecode-system-version “3.4”print-name “Blood group A”

}


Code Value (example 2a)

Patient Sex == Code Value {value “M”,code-system “HL70001”code-system-version “3.0”print-name “Male”

}


Code Value (example 2b)

Tetanus Special Circumstances == Code Value {value “3”,code-system “DEEDS4.31” -- subpart needed?code-system-version “1.0”print-name “only the year is known”

}



Patient Sex == Code Value {code-system “HL70001”code-system-version “3.0”replacement “Male Pseudo-hermaphrodite”

}

• Desired value is not a member of the coding system


Code Value (incorrect 4)

Patient Sex == Code Value {value “MPH”code-system “HL70001”code-system-version “3.0”replacement “Male Pseudo-hermaphrodite”

}

• Value and Replacement should not be present at the same time.



Patient Blood Type == Code Value {value “F-D1111”,code-system “SMI” -- from a table

}

• Code System Version and Print Name are not required.


Code Phrase (definition)

• ORDERED LIST OF Code Value


Code Phrase (example 1)

Body Location == Code Phrase {{ value “R” code-system “99Lab” -- A Local coding system print-name “right” } { value “ARM” code-system “99Lab” print-name “arm” }

}

• Note that the “roles” (side, body part) of these items are not specified. Roles can be specified by making separate coded fields in a message.


Code Phrase (example 2)

Body Location == Code Phrase {{value “R” code-system “99Lab” -- A Local coding system print-name “right” }{code-system “99Lab” replacement “anterior axillary fold” }

}

• A Code Phrase can consist of a true code and a replacement code as part of the same ordered list.


Code Translation (definition)

• term (Code Phrase, required)

• origin (reference to Code Translation, required)

• producer (TII, optional)

• quality (floating point number, optional)

• label (Character String, optional)

(Examples are shown with Concept Descriptor)


Concept Descriptor (definition)

• SET OF Code Translation (required)

• Original Text (Free Text, optional)


Go To Word Document


Local Vocabulary Use

• Can only be used with qualifier Strength:CWE

• The complete domain is a union of standard domain plus local concepts (as a union of the two)

• Rules– Local concept can not replace standard concept– Local code system names must start with “99” – Local codes should be submitted to HL7 for inclusion in

standard domain and forwarded to terminology developers


General process of maintaining domains

• Follow pattern of RIM harmonization

• Vocabulary TC appoints facilitators

• Message development TCs have stewardship– Ultimate authority for domain contents– Follow RIM harmonization rules

• Vocabulary Facilitators– Insure that good vocabulary practices are followed– Actual maintenance of domain specification database– Submit new concepts to vocabulary providers

• All vocabulary/terminology providers can provide mappings to HL7 domains


Domain specification table maintenance

• Available on HL7 web site– All members can read tables

• Edit Permissions table– who can edit which domains– vocabulary co-chairs maintain permissions table

• Assigned persons make edits (proposed status)

• Entries reviewed by Vocab Review Committee

• Reports presented to RIM harmonization process

• Approved changes reflected by status chanages

• HL7 standard versions synch’ed with edit versions


Good Vocabulary Practices

• Need to define– Jim Cimino– Peter Elkin (ASTM Standard)

Documents

MDF99 Vocabulary Chapter HL7 Working Group Meetings April 26, 1999 Toronto, Canada Stan Huff - [email protected]