http://www.hl7.org.uk

CDAClinical Document Architecture

Charlie Bishop

Agenda

• What is CDA ?

• CDA overview

• Technical insight

• CDA and the MiM

Overview

• Clinical Document Architecture (CDA)

• CDA = International Standard– a development of the HL7

standards developing organization

• CDA is– a document markup standard for the structure and

semantics of exchanged "clinical documents"– a defined and complete information object

• for storage and exchange• can include text, images, sounds and

other multimedia content– documentation of observations and other services

Characteristics

• A Clinical Document has the following characteristics:– Persistence– Stewardship– Authentication– Context– Wholeness– Human Readability

• Conformance with these characteristics is an integral part of the standard

Brief History

• Level 1– Generic document structure (section, paragraphs, list,

tables…)

• Level 2– domain-specific document types– document ontology– constrainable for (domain-) compliant content

• Level 3– fine-grained definitions / markup as defined in the RIM

Structure and representation

• Structure– A header which provides contextual data:

• Facilitates the exchange and interpretation of the document and its storage in an EHR.

– A body:• Clinical information, structured in the form of

sections, paragraphs, lists, tables…

HeaderHeader

BodyBody

• XML Encoding– Human readable…

– …software processable– Validated by a schema

Diagnostic:

Asthma, history of smoking

<section>

<caption>Diagnostic:</caption>

<content>Asthma, history of smoking </content>

</section>

<section>

<caption>Diagnostic:</caption>

<content>Asthma, history of smoking </content>

</section>

Style sheet

CDA Release 2 (2005)

• HL7 v3 StandardRIM R-MIM HMD Schema XML

Narrative blocks

human

Entries

machine

A CDA R2 document consists of a mixture of « narrative blocks » and structured « entries ».

HeaderHeader

BodyBody

text

Observation

Substance administration

Body site

Procedure

Patient encounter

« Organizer »

Multimedia observation

CDA Information Model

CDA Header CDA BodyExt. Ref.CDA Entries

Clinical Document

Participations

Non-XMLor

StructuredBody

Nested Sectionswith Narrative

Clinical Statements

Custodian

RecordTarget Encounter

RelatedDocuments

LinkedArtifacts

Medication

Observation

Procedure

Body Structure

Main Components of CDA

<ClinicalDocument> ... <StructuredBody> <Section> <text>...</text> <Observation> ... </Observation> <Observation> <reference> <ExternalObservation> ... </ExternalObservation> </reference> </Observation> </Section> <Section> <Section>...</Section> </Section> </StructuredBody></ClinicalDocument>

DOCUMENT

SECTIONS

BODY

Header

ENTRIES

Narrative Block

ExternalReferences

Section structure

<Section> <code code="10153-2" codeSystem="LOINC">Anamnese</code> <text> <list> <item><content>Asthma</content></item> <item><content>High Bloodpressure</content></item> <item><content ID="a3">Osteoarthritis, right knee</content></item> </list> </text> <entry> <contextConductionInd value="TRUE"/> <Observation classCode="COND"> <code code="G-1001" codeSystem="SNOMED" displayName="prior diagnosis"/> <value code="D1-201A8" codeSystem="SNOMED" displayName="Osteoarthritis"> <originalText><reference value="#a3"/></originalText> </value> <targetSiteCode code="T-15720" codeSystem="SNOMED" displayName="Knee"> <qualifier> <name code="G-C220" codeSystem="SNOMED" displayName="Laterality"/> <value code="G-A100" codeSystem="SNOMED" displayName="right"/> </qualifier> </targetSiteCode> </Observation> </entry></Section>

Clinical Statement

• HL7 v3 model for structured clinical information

• Allows consistent representation across domains

• Used by CDA

Questions

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