Electronic Exchange of Structured Interim Discharge Summaries Using the XML- based Clinical Document Architecture Grace Paterson, Medical Informatics Xiaoli Wang, Dalhousie Computer Science

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

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

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 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

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

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

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 #

CDA and Knowledge Integration  Publishers submit abstracts to MedLine in XML  XML tag provides external link to fulltext for MedLine abstract  CDA has,,,, and  Nova Scotians can link from CDA document to Electronic Bookshelf entries in doctorsns.com for prompts and “Information Given to Patient”

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

Feedback Model

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.

Necessary and Sufficient Components  Persistence  Stewardship  Potential for Authentication  Wholeness  Human Readability

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

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,,,,,  Encounter data describe the setting in which the documented encounter occurred. It includes,,,,.  Provider include the person who participated in the services being documented.  Patient include the patient and other significant participants (such as family members)

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., is the external coding scheme ICD10

Most Responsible Diagnosis Unstable Angina Y Object Identifier for ICD10 coding scheme ICD10

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

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)

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.

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

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

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