Using the XMLBased Clinical Document Architecture for Exchange of Structured Discharge Summaries

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Using the XML-Based Clinical Document
Architecture for Exchange of Structured Discharge
Summaries

• Grace I. Paterson, Michael Shepherd, Xiaoli Wang,
  Carolyn Watters, and David Zitner

DALHOUSIE University
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Overview

• Health Level Seven (HL7) and XML
• Clinical Document Architecture (CDA)
• Levels within the CDA
• Vocabulary Domains
• Implementation
• Clinical/Admin Information Exchange
• Current Status

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Health Level Seven (HL7)

• HL7 is an ANSI-accredited Standards Development
  Organization
• Domain is clinical and administrative data
• Focus is the interchange of health care data
• Level 7 refers to the highest level,
  applications, of the communications model for
  Open Systems Interconnection

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HL7 Mission

• Clinical Interoperability
• Interoperability
• ability of two of more systems or components to
  exchange information and to use the information
  that has been exchanged.
• Source IEEE Standard Computer Dictionary A
  Compilation of IEEE Standard Computer Glossaries,
  IEEE, 1990

Functional Interoperability
Semantic Interoperability
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HL7 and SGML/XML

• Initial release of HL7 Version 3 slated for
  December 2001 will use only XML encoding
• Two groups in HL7 SGML/XML
• XML as an alternative syntax for messages
• Structured Documents Technical Committee
• An architecture for structured documents defines
  relationships between documents and document
  specifications in terms of specialization and
  inheritance a Clinical Document Architecture

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Clinical Document Architecture (CDA)

• Kona Proposal drafted in 1996 (Kona Mansion)
• Clinical Document Architecture (CDA) is a
  specification for exchanging clinical documents
  using eXtensible Markup Language (XML)
• Leverages the use of XML, the HL7 Reference
  Information Model and coded vocabularies to
  specify the structure and semantics
• Machine and Human-readable documents
• Approved as an ANSI standard November 2000

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A CDA Document

• A CDA document is a defined and complete
  information object
• Can exist outside of a messaging context and/or
  can be a payload within an HL7 message

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Clinical Documents in QEII

• Currently each page of paper chart reviewed to
  produce Discharge Summary and Abstract
• Demographic information
• Length of Stay
• Diagnoses and Procedures
• Most of this information is produced by
  clinicians
• Huge potential cost savings if the summary could
  be captured concurrent with care and used for
  discharge communication

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Discharge Summary Hospital Communication to
Family Doctor

• QEII Department of Medicine Structured Discharge
  Summary
• Header Information (Participants and Roles
  Patient, Sender, Recipient)
• Most Responsible Diagnosis
• Comorbidities/Cardiac Risk Factors
• Course in Hospital and Conclusions
• Pertinent Investigations/Lab Results
• Further steps and scheduling

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Referral Communications

• From Family Physician to Hospital
• Patient Information
• Reason for referral
• Symptoms and Duration
• Investigations and Results
• Diagnosis and Treatment
• Prescribed Medications

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Features of DoctorPortal

• Adding a discharge or referral
• Finding a discharge or referral
• Editing a discharge or referral
• Querying a discharge or referral
• Listing all discharges and referrals assigned to
  a given doctor

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Query the Database
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Levels within the CDA

• Level One is the root
• Most general specification (low-hanging fruit)
• Defined and complete information object web
  implementation of paper documents to start
• RIM classes are used in the CDA Header
• Terms from controlled vocabularies in body
• Level Two will be a specialization of Level One
• Level Three Clinical content can be marked up to
  the extent that it is modeled in the HL7 RIM

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Level One CDA Document

• Composed of CDA Header and CDA Body
• Purpose of the CDA Header is to enable clinical
  document exchange across and within institutions
• Coded entries uses HL7 Version 3 Data Types

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HL7 Version 3 Data Types

• XML Element Names map to Data Types
• _cd vocabulary domain has coding strength
• CNE coded, no extensions
• CWE coded, with extensions (allows local codes)
• Make use of published authoritative sources of
  code values
• _tmr document time stamp
• _id identifier
• _nbr number
• Vocabulary domains may be HL7-defined concepts or
  recognized coding schemes such as SNOMED, READ,
  ICD10, Medcin

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Captions, Coded Captions, and Registered
Vocabularies

• ltsectiongt
• ltcaptiongtMost Responsible Diagnosislt/captiongt
• ltsectiongt
• ltcaptiongtUnstable Angina
• ltcaption_cd VI20.0
  S2.16.840.1.113883.6.3/gt
• lt/captiongt
• ltparagraphgt
• ltcontentgtYlt/contentgt
• lt/paragraphgt
• lt/sectiongt

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Level One Document Instance

• lt?xml version"1.0"?gt
• lt!DOCTYPE levelone PUBLIC "-//HL7//DTD CDA Level
  One 1.0//EN" "dischargesummary.dtd"gt
• ltlevelonegt
• ltclinical_document_headergt
• lt/ clinical_document_headergt
• ltbody confidentiality CONF1gt
• lt/bodygt
• lt/levelonegt

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Level One CDA Header

• 1. Document information includes ltidgt, ltset idgt,
  ltversion_nbrgt, ltdocument_type_cdgt,
  ltconfidentiality_cdgt, ltdocument_relationshipgt
• 2. Encounter data describe the setting in which
  the documented encounter occurred and includes
  ltpatient_encountergt, ltpractice _setting_cdgt,
  ltencounter_tmrgt, ltservice_locationgt, ltaddrgt.
• 3. Provider includes the persons who participated
  in the services being documented
• 4. Patient includes the patient and other
  significant participants (such as family members)

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Level One CDA Body

• Nested containers in Level One body sections,
  paragraphs, list and tables.
• Minimal amount of markup and minimal constraint
  for this markup

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Doctor Portal Implementation

• The portal has three features
• 1. Ability to add, edit, find, and query
  discharge summaries
• 2. Ability to add, edit, find, and query referral
  forms
• 3. Ability to list all discharges and referrals
  assigned to a specific doctor
• Javascript and HTML implement the interface and
  interact with the user as information is entered
  into the form

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HTML
Web interface
JAVA Servlet
SAX Parser
Validates XML
Handles requests responses
XML DB API
dbXML Database
Performs dbXML Operations
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Database Platform

• dbXML is an open source Native XML Database
• stores and indexes compressed XML documents in
  order to provide that data to a client
  application with very little server-side
  processing overhead
• provides functionality that is unique to XML
  data, which can't easily be reproduced by
  relational databases
• http//www.dbxml.org/ for Users Manual

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Clinical/Administration Information Exchange

• CDA is sufficient backbone for communication
  between Information Systems in Physician Offices
  and Hospital
• Canadian hospitals abstract each patient record
  for Canadian Institute for Health Information
• Information should support clinical,
  administration, education and research

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Current Status

• Working demonstration system
• Planned implementations for 2002
• HealthInfoRx Lifelong Learning for Chronic
  Disease Patients
• CDA will be used for physician to physician
  referral/discharge communications for patients in
  Inflammatory Bowel Disease Clinic (Level Two)
• Concurrent Review Document
• Data collection January 2002 using XML system
• Test of implementation in a District (Level Three)

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Thank You

• Questions?
• Further Information
• www.medicine.dal.ca/dmedinfo
• Grace.paterson_at_dal.ca

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Acknowledgements

• Dr. Michael Shepherd, Computer Science, Dalhousie
• Dr. Carolyn Watters, Computer Science, Dalhousie
• Dr. David Zitner, Director, Medical Informatics,
  Dalhousie
• Dr. John Ginn, Medical Informatics, Dalhousie
• Kathy MacNeil, Director, Patient Information
  Services, QEII Health Sciences Centre
• Patient Care Record Committee, Capital Health
  District Authority
• Mary Eileen Wall, Clinical Informatics
  Coordinator, QEII Health Sciences Centre
• Sandra Cascadden, Director of IT Services, QEII
  Health Sciences Centre
• Dr. Elizabeth Cowden, Head, Department of
  Medicine, QEII
• Ron Soper, Computer Science CO-OP Student