1. HL7’s Clinical Document Architecture
Liora Alschuler
HIMSS
Dallas, Texas February, 2005

2. 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
Also contributing: Bob Dolin, MD, Kaiser-Permanente; John Madden, MD, Duke University Medical Center

3. Clinical Document Architecture: CDA
What is it?
How does it allow you to:
Do simple things simply
Invest in information (doing complex things carefully)

4. 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,…)

5. CDA: A Document Exchange Specification
This is a CDA
and this

6. 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

7. CDA: XML XML is Extensible Markup Language (www.w3c.org)
In XML, structure & format are conveyed by markup which is embedded into the information

8. Sample CDA

9. CDA = header + body CDA Header CDA Body
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

10. 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

11. 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

12. 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

13. CDA Body: Machine Processible
Clinical statement
Observation
Procedure
Organizer
Supply
Encounter
Substance Administration
Observation Media
Region Of Interest
Act
Optional

14. ? = = CDA Body: Why isn’t XML + SNOMED enough?
“hives”: SNOMED CT =
“Dr. Dolin asserts that Henry Levin
manifests hives as a previously-diagnosed
allergic reaction to penicillin” =

15. First: human readable

16. Next: series of related statements
Allergy to penicillin
Observation: RIM-defined
Prior dx: SNOMED Allergy to penicillin: SNOMED
Hives
Prior dx: SNOMED
Hives: SNOMED
Hives is a manifestation of a reaction to penicillin
Relationship: RIM-defined
Next: series of related statements

17. Then: supply context
Who is the subject?
Target: RIM-defined
Id: local

18. CDA RMIM How are these concepts, relationships defined? CDA Header
CDA Body,
Section, and
Narrative Block
CDA Entries
Extl
Refs

19. 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

20. 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

21. 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

22. Low End Investment in CDA
Many forms of document creation technology
Voice (dictation, transcription)
eForm
EHR (CDA is output as “report”)

23. What is the simplest way to create a CDA document?
Enter
minimal
metadata
Point to document body
See HL7.org NLM Project: freely available application (by 3/1)

24. What you can do with simple CDA documents: the registry hub
4. Retrieve
“what imaging reports are available from the last episode?”
1. Create documents
2. Register
3. Discover
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

25. A tip of the hat to… Aluetietojärjestelmä
40% of Finnish population covered including Helsinki

26. 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

27. A single data REPRESENTATION standard
facilitates multiple
document PRESENTATION standards !

28. CAP/ACoS standards compliant, template-driven data entry
Pathologist view:
CAP/ACoS standards compliant, template-driven data entry

29. Repository view:
HL7-CDA standard XML with XQuery-ready, context-linked SNOMED encodings

30. Traditional format, print/electronic delivery
South Hospital
Clinician view:
Traditional format, print/electronic delivery

31. Irrelevant items filtered, stage computed automatically
South Hospital
Tumor registrar view:
Irrelevant items filtered, stage computed automatically

32. One CDA, many applications: pathology
Display or print (referring physician’s view
Source CDA
(pathologist, author’s view)
Archival CDA XML
Tumor Board, synopsis, meets CAP reporting guidelines

33. 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

34. The Challenge: Integrate Patient Care and Clinical Research Data
Patient Care World
Clinical Research World
Electronic Medical Record
The Void

35. 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

36.   CDA in Starbrite Trial   Current processes (dual source)
Manual creation and re-entry of CRF
HIS
validation 
lab, ADT, meds, source documents db
LIS
display
manual entry to CRF
re-key CRF 
CLINIC
CRO
Current processes (dual source)
HIS 
lab, ADT, meds, source documents
LIS
display
dictate chart note 
Redundant creation of chart note

37.  CDA in Starbrite Trial  Proposed processes (single source)
Merged workflow: electronic CRF re-used in chart note
HIS
validation 
lab, ADT, meds, source documents
CDA/ ODM
LIS db
display
eCRF
Proposed processes (single source) 
dictate chart note
CLINIC
ARO

38. One CDA, many applications: clinical trials
Clinic note inserted into patient chart
See demo here, Microsoft pod!
Source CDA
(principal investigator, author’s view)
Archival CDA XML
Case report form submission to research database

39. Investing in Information
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
cost x
80/20 √
benefit

40. 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: and
New project within HL7
Looked at issues raised by David Markwell (and previously identified by others)

41. 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.

42. 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

43. 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

44. CDA: doing simple things simply, & more complex things slowly
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)

46. Thank you!
Questions?