Grace Paterson, Medical Informatics Xiaoli Wang, Dalhousie Computer Science

1. Electronic Exchange of Structured Interim Discharge Summaries Using the XML-based Clinical Document Architecture Grace Paterson, Medical Informatics Xiaoli Wang, Dalhousie Computer Science http://www.medicine.dal.ca/dmedinfo

2. XML Standard for Healthcare • Comprehensive healthcare information exchange standard must include the full electronic health record, not just fielded data • Clinical Document Architecture (CDA) is a specification for exchanging clinical documents using eXtensible Markup Language (XML) • Bob Dolin’s Ehealth 2001 Workshop presentation available on CIHI HL7 website

3. Power of XML • XML, like HTML, is a derivative of Standard Generalized Markup Language (SGML) • Information Technology’s “lingua franca” • Current “must-have” feature in software • Browsers, Notepad, SAS, Oracle, Internet Security • E-Commerce and Automating Transactions • E-Health gets a tremendous boost at low cost

4. Power of a Think Tank - Kona Proposal • Week of July 7, 1997, a group of physicians, healthcare system vendors and consultants met at Kona Mansion, NH • OUTCOME: a multi-level architecture for the exchange of Electronic Health Care Records • April 2000. Kona Proposal was revised into the PRA (Patient Record Architecture) but went to HL7 ballot August 2000 as CDA (Clinical Document Architecture) • Xiaoli phoned Liora Alschuler for specifications

5. CDA and Shared Care • CDA gives priority to documents generated by clinicians involved in direct patient care • Care occurs where the patient’s pillow is - hospital, family physician, long term care • CDA standard can be readily implemented, and is platform and application independent • Promotes shared care in appropriate setting

6. Structured Discharge Summary QEII DEPARTMENT OF MEDICINE • Header Information (Participants and Roles) • Most Responsible Diagnosis/Admitting Dx • Comorbidities/Cardiac Risk Factors • Allergies • Course in Hospital • Pertinent Investigations/LabResults

7. Structured Discharge (con’d) • Follow Up • Recommendations for Family Doctor • Medications on Discharge (unchanged from admission, altered, new) • Discharge Outcome Measures • Physician’s Signature/Status/Print Name • Discharge Summary and Dictated Job #

8. CDA and Knowledge Integration • Publishers submit abstracts to MedLine in XML • XML tag <FullText> provides external link to fulltext for MedLine abstract • CDA has <content>, <link>, <coded_entry>, <observation_media>, and <local_markup> • Nova Scotians can link from CDA document to Electronic Bookshelf entries in doctorsns.com for prompts and “Information Given to Patient”

9. CDA and Outcomes Research • From time of Florence Nightingale to mid-60s, Hospital Annual Reports documented discharges as recovered, improved, no change, worsened, died • Generic scales (SF-36) • Disease specific scales (IBDQ) • Health Status (comfort, function, lifespan) • Health Outcomes and HL7 V3 Data Types

10. Feedback Model

11. Key features of CDA • A clinical document should be human readable. • The clinical document will be legally authenticated, and the authentication of a clinical document will be applied to the whole, not portions of the document. • Entrusted person or organization will maintain the clinical document. • A CDA document can include text, images, sounds and other multimedia content. • CDA documents are encoded in XML. • CDA documents will be consistent with HL7 data types.

12. Necessary and Sufficient Components • Persistence • Stewardship • Potential for Authentication • Wholeness • Human Readability

13. Specification Overview of CDA Architecture • In Level One, the level one DTD is for all kinds of clinical document. • In Level Two, a specific clinical document will be defined in consultation with Professional Societies • QEII Hospital has gone through up to 12 revisions of Cardiology, Internal Medicine, Geriatrics, COPD templates • We were able to implement each template in Level One • Defined process for going from CDA Level One to CDA Level Three - tightly coupled with HL7 V3 Data Types • Deliberate decision to wait for V3 ballot results Aug 2001

14. XML Design (Header) • CDA Header is used to uniquely identify a clinical document in order to exchange it among organizations • There are four components for header: document information, Encounter data, providers and patients • Document information includes <id>, <set id>, <version_nbr>, <document_type_cd>, <confidentiality_cd>, <document_relationship> • Encounter data describe the setting in which the documented encounter occurred. It includes <patient_encounter>, <practice _setting_cd>, <encounter_tmr>, <service_location>, <addr>. • Provider include the person who participated in the services being documented. • Patient include the patient and other significant participants (such as family members)

15. XML (Level One Body) • Nested containers in Level One body: sections, paragraphs, list and tables. • Minimal amount of markup and minimal constraint for this markup. • Coded entries uses HL7 Version 3 Data Types • Appendix A lists object identifiers, e.g., 2.16.840.1.113883.6.3 is the external coding scheme ICD10

16. <coded_entry> <section> <caption>Most Responsible Diagnosis</caption> <section> <caption>Unstable Angina <caption_cd V=“I20.0” S=“2.16.840.1.113883.6.3”/> </caption> <paragraph> <content>Y</content> </paragraph> </section> ICD10 Object Identifier for ICD10 coding scheme

17. Implementation • To generate a Discharge Summary, the user enters the information into Web form • Information is POSTed to Web server where a Java servlet parses the input data and marks up the data into the CDA format • Written to disk as an XML file • Retrieved as XML file by Java servlet and parsed into constituent elements by SAX parser, converted to HTML and displayed

18. Implementation • XML describes the meaning of content, independent of its display • There are two style sheets for XML • CSS (Cascading Style Sheet) • XSL (XML Style Sheets Language) • User enters chart number for search and choice of display style (web form or discharge summary)

19. Implementation Parser of XML • We must access information in XML documents through an XML parser. • There are two kinds of parser: SAX and DOM, SAX is event-based parser and DOM is object-based parser, the core object is Node.

20. Implementation • Several events for SAX: • startDocument()/endDocument() • startElement()endElement() • Characters() • Several methods for DOM: • NodeType, parentNode, childNode, firstchild, getElementByTagName(), getText(), getNameItem().

24. Summary and Next Steps • The procedure of this project includes understanding specification, designing a system, implementing the system, and the final testing. • The purpose of the system is to meet the need of an extensible, hierarchical, structured clinical document exchange. • Work-in-progress with other CS Students: • CDA document storage in Statistical Analysis System (SAS) • CDA integrated with Electronic Bookshelf • Automatic Indexing Using UMLS for Coded Entries

25. Acknowledgements • Dr. Michael Shepherd, Computer Science • Dr. Carolyn Watters, Computer Science • Dr. David Zitner, Director, Medical Informatics; Chair, Health Records Committee, QEII Health Sciences Centre • 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 • Ron Soper, Computer Science CO-OP Student