HL7’s Clinical Document Architecture

Liora AlschulerHIMSS

Dallas, Texas February, 2005

About me Liora Alschuler

alschuler.spinosa, consultants Co-chair HL7 Structured Documents TC Co-editor, CDA Member, 2005, HL7 Board of Directors Project manager for Operation Jumpstart,

(initial design of CDA) past Chair, XML SIG liora@the-word-electric.com

Also contributing: Bob Dolin, MD, Kaiser-Permanente; John Madden, MD, Duke University Medical Center

Clinical Document Architecture: CDA

What is it? How does it allow you to:

Do simple things simply Invest in information (doing complex

things carefully)

What is CDA?

ANSI/HL7 CDA r1-2000 (Release one) On CD, includes prose spec, RMIM, DTDs

December 2004 ballot (Release two) Structured Documents Tech Cmte, zip file on

HL7.org – PASSED, will be published shortly A specification for document exchange

using XML, the HL7 Reference Information Model (RIM) Version 3 methodology and vocabulary (SNOMED, ICD, local,…)

CDA: A Document Exchange Specification

This is a CDA and this and this and this and this and this and this

CDA: A Document Exchange Specification

A CDA can be a Discharge Summary Referral (CCR is one such) Progress Note H&P Public health report

… any content that carries a signature

XML is Extensible Markup Language (www.w3c.org)

In XML, structure & format are conveyed by markup which is embedded into the information

CDA: XML

Sample CDA

CDA = header + body

CDA Header Metadata required for document

discovery, management, retrieval CDA Body

Clinical report Discharge Summary Referral Progress Note H&P Public health report

… any content that carries a signature

CDA Header

The header describes: The document itself (unique ID, document

type classification, version) Participants (providers, authors,

patients…) Document relationships (to orders, other

documents…) Metadata sufficient for document

management

CDA Body: two types of markup Human-readable “narrative block”, all

that is required to reproduce the legal, clinical content

Optional machine-readable CDA Entries, which drive automated processes

CDA Body: Human-readable

paragraph list table caption link content revise (delete/insert) subscript/superscript special characters (e.g., symbols, Greek letters) in

Unicode emphasis line break renderMultiMedia (non-XML graphics, video…)

required

CDA Body: Machine Processible

Clinical statement Observation Procedure Organizer Supply Encounter Substance Administration Observation Media Region Of Interest Act

Optional

“Dr. Dolin asserts that Henry Levin manifests hives as a previously-diagnosed allergic reaction to penicillin”

“hives”: SNOMED CT 247472004

CDA Body: Why isn’t XML + SNOMED enough?

First: human readable

Next: series of related statements

Allergy to penicillin

Observation: RIM-defined

Prior dx: SNOMED Allergy to penicillin: SNOMED

HivesPrior dx: SNOMED Hives: SNOMED

Hives is a manifestation of a reaction to penicillinRelationship: RIM-defined

Who is the subject?

Target: RIM-defined

Id: local

Then: supply context

ExtlRefsCDA EntriesCDA Header CDA Body,

Section, andNarrative Block

CDA RMIMHow are these concepts, relationships defined?

Investing in Information

CDA XML can be simple CDA XML can be complex Simple encoding relatively inexpensive Complex encoding costs more You get what you pay for:

like charging a battery, the more detailed the encoding the greater the potential for reuse

CDA: Return on Investment

Low end: Access to documents “please send referral letter to…” “please get me the discharge summary…” “what imaging reports are available from

the last episode?” High end: Reuse

Send synopsis to tumor board Attach to claim for automated adjudication

of payment Extract data for clinical research

Low End Applications for CDA Persistant, accessible, human-readable

documents Document requirements:

CDA header Release One or Two body

Narrative block Non-semantic markup (HTML-like)

Document options: More complex markup can be inserted,

to be used or ignored

Low End Investment in CDA Many forms of document creation

technology Voice (dictation, transcription) eForm EHR (CDA is output as “report”)

What is the simplest way to create a CDA document?

Enterminimal metadata

Point to document body

See HL7.org NLM Project: freely available application (by 3/1)

What you can do with simple CDA documents: the registry hub

“what imaging reports are available from the last episode?”1. Create documents 2. Register 3. Discover

4. Retrieve

Ubiquitous access to distributed information By class of document, patient, provider, encounter (CDA

header metadata) Documents remain under local control Document creation technology evolves under local control Registry (hub) for access control, identifier xRef

A tip of the hat to…Aluetietojärjestelmä

40% of Finnish population covered including Helsinki

Investing in Information

Simple documents retrieval, display metadata registry

Two examples of higher-level investment: HIMSS 2004, Dr. John Madden, Duke

University Medical Center, created a CDA pathology note that doubles as a tumor board report

Also at Duke, the Starbrite “Single Source” Proof of Concept for clinical trials

A singleA singledata data

REPRESENTATIONREPRESENTATION standard standard

facilitates multiplefacilitates multiple document document

PRESENTATIONPRESENTATION standards !standards !

Pathologist view:Pathologist view:CAP/ACoS standards CAP/ACoS standards compliant, template-compliant, template-

driven data entrydriven data entry

Repository view:Repository view:HL7-CDA standard XML HL7-CDA standard XML

with XQuery-ready, with XQuery-ready, context-linked SNOMED context-linked SNOMED

encodingsencodings

South Hospital

Clinician view:Clinician view:Traditional format, Traditional format,

print/electronic print/electronic deliverydelivery

South Hospital

Tumor registrar view:Tumor registrar view:Irrelevant items Irrelevant items filtered, stage filtered, stage

computed computed automaticallyautomatically

One CDA, many applications: pathology

Source CDA

(pathologist, author’s view)

Display or print (referring physician’s view

Archival CDA XML

Tumor Board, synopsis, meets CAP reporting guidelines

Investing in Information

“Single Source” Create once Use many Reuse clinical data in clinical trials

Duke Clinical Research Institute Proof of Concept Principals:

Landen Bain, Rebecca Kush, Liora Alschuler Microsoft, primary technology partner

The Challenge: Integrate Patient Care and Clinical Research Data

Clinical Research World

The Void

Electronic Medical Record

Patient Care World

Single Source vs Previous Solutions eSource & electronic data capture

redundant with creation of clinic note require information reside in EMR/EHR proprietary data formats

CDA & CDISC in “single-source” capture trial data, merge it into clinic

note (re-use) work with current technology, workflow open, non-proprietary data formats

dblab, ADT, meds, source documents

display manual entry to CRF

re-key CRF

lab, ADT, meds, source documents

display dictate chart note

LIS

LIS

HIS

HIS

Manual creation and re-entry of CRF

Redundant creation of chart note

CLINIC CRO

validation

Current processes (dual source)

CDA in Starbrite Trial

db

LIS

HIS

lab, ADT, meds, source documents

display eCRF

dictate chart note

Merged workflow: electronic CRF re-used in chart note

validation

Proposed processes (single source)

CLINIC ARO

CDA/ ODM

CDA in Starbrite Trial

One CDA, many applications: clinical trials

Source CDA

(principal investigator, author’s view)

Clinic note inserted into patient chart

Archival CDA XML

Case report form submission to research database

See demo here, Microsoft pod!

Investing in Information

cost

benefit

√

80/20

Disecting the curve What is easy:

Header Human-readable body Low degree of coding

What is hard: Concensus on

semantic content requirements

Model/vocabulary interface

Investing in Information

Example of what is hard TermInfo 2004 conference

NASA August 1-4, 2004, Houston, TX Notes posted to the summit’s web page:

http://csd2.no-ip.net/Composition/ and www.terminfo.org

New project within HL7 Looked at issues raised by David

Markwell (and previously identified by others)

Investing in information: what is hard? Issue 1: Code/value dichotomy

abdominal tenderness is observed examination (code) / abdomen tender

(value); abdominal examination / abdomen tender; abdominal palpitation / abdomen tender; abdominal tenderness / present, etc.

Investing in information: what is hard? Strong collaborative effort established

to address issues Most syntatic issues addressed, full

concentration on semantic interoperability

Issues will be resolved, but will take time and experience

Investing in Information: phased approach

Lay groundwork CDA header metadata XML R1 or R2 CDA body

Build Concensus on requirements Understanding of modeling process Vocabulary glossary

Understand Relationship of vocabulary to model

Introduce interoperable semantic content as requirements and business drivers dictate

What can be done now Basic (Level One) CDA (R1 or R2) can be created

with any degree of technical sophistication Document scanner+web form Transcription Electronic health record

What can be done later Increase coding sophistication as business

requirements dictate (return on investment and regulation)

http://www.intersystems.com/mt_washington_vision.pdf

CDA: doing simple things simply, & more complex things slowly

Thank you!

Questions?