HL7’s Clinical Document
Architecture
Liora Alschuler
HIMSS
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
[email protected]
 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
CDA: XML
 XML is Extensible Markup Language
(www.w3c.org)
 In XML, structure & format are conveyed by
markup which is embedded into the
information
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
required
content
revise (delete/insert)
subscript/superscript
special characters (e.g., symbols, Greek letters) in
Unicode
emphasis
line break
renderMultiMedia (non-XML graphics, video…)
CDA Body: Machine Processible

Clinical statement









Observation
Procedure
Organizer
Supply
Encounter
Substance Administration
Observation Media
Region Of Interest
Act
Optional
CDA Body: Why isn’t XML + SNOMED enough?
“hives”: SNOMED CT 247472004
“Dr. Dolin asserts that Henry Levin
manifests hives as a previously-diagnosed
allergic reaction to penicillin”
First: human readable
Allergy to penicillin
Next: series of
related
statements
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
Then: supply context
Who is the subject?
Target:
RIM-defined
Id:
local
How are these concepts, relationships
CDA RMIM
defined?
CDA Header
CDA Body,
Section, and
Narrative Block
CDA Entries
Extl
Refs
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?
Enter
minimal
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
4. Retrieve
1. Create documents
2. Register
“what imaging
reports are available
from the last
episode?”
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
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 single
data REPRESENTATION
standard
facilitates multiple
document PRESENTATION
standards !
Pathologist view:
CAP/ACoS standards
compliant, templatedriven data entry
Repository view:
HL7-CDA standard XML with
XQuery-ready, context-linked
SNOMED encodings
South Hospital
Clinician view:
Traditional format,
print/electronic delivery
South Hospital
Tumor registrar view:
Irrelevant items filtered,
stage computed
automatically
One CDA, many applications:
pathology
Display or print
(referring physician’s
view
Source CDA
Archival CDA
XML
(pathologist,
author’s view)
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
Patient Care World
Clinical Research World
Electronic
Medical Record
The Void
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
CDA in Starbrite Trial
Manual creation and re-entry of CRF
HIS
lab, ADT,
meds,
source
documents
LIS
validation

display

db
manual
entry to
CRF
CLINIC
re-key CRF
CRO
Current
processes
(dual
source)
HIS
lab, ADT,
meds,
source
documents
LIS


display
dictate
chart note
Redundant creation of chart note
CDA in Starbrite Trial
Merged workflow: electronic CRF
re-used in chart note
HIS
lab, ADT,
meds,
source
documents
LIS
validation

display
CDA/
ODM
db
eCRF
Proposed
processes
(single
source)

dictate
chart note
CLINIC
ARO
One CDA, many applications: clinical
trials
Clinic note inserted
into patient chart
Source CDA
(principal
investigator,
author’s view)
Archival CDA
XML
Case report form
submission to
research database
See demo here,
Microsoft pod!
Investing in Information
cost
80/20
√
benefit
 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
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)
 http://www.intersystems.com/mt_washington_vision.pdf
Thank you!
Questions?
Descargar

CDA & the Primacy of Information