Health Information Technology Standards. Series Editor: Tim Benson

Transcription

1 Health Information Technology Standards Series Editor: Tim Benson

2

3 Tim Benson Principles of Health Interoperability HL7 and SNOMED Second Edition

4 Tim Benson Abies Ltd Hermitage, Thatcham Berkshire UK ISBN nd edition ISBN nd edition (ebook) ISBN st edition ISBN st edition (ebook) DOI / Springer Dordrecht Heidelberg New York London Library of Congress Control Number: British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Springer-Verlag London 2012 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Printed on acid-free paper Springer is part of Springer Science+Business Media (

5 This book is dedicated to my sons Laurence, Oliver, Alex, and Jamie.

6

7 Foreword to the First Edition Health data standards are a necessary component of interoperability in health care. Aggregation of health-related data mandates the use of standards, and aggregation is necessary to support safe and quality care. The American Recovery and Reinvestment Act (ARRA) includes $19 billion dollars in direct funding and an additional $18.5 billion in returned savings tagged to the use of health information technology (HIT). The resulting expanding use of HIT has engaged a growing number of stakeholders, many of whom now realize the value of standards. All aspects of creating and meaningful use of electronic health records (EHRs) require standards. With the increasing demand for individuals knowledgeable in what standards are available and how and when to use those standards, this book is most welcome. The author, Tim Benson, has been engaged in the creation of standards since the beginning. His experiences span organizations including HL7, CEN, and ISO and terminologies such as SNOMED and LOINC. He has engaged the global community and understands similarities as well as differences among the global community. He has a top reputation as a teacher and writer within the international community. I know no other individual more qualified to write this book than Tim Benson. In Principles of Health Interoperability HL7 and SNOMED, Tim focuses on major contributors to the set of required standards. In the first section, he lays out a framework for why interoperability is important and what is needed to accomplish that interoperability. Health Level Seven (HL7) is preeminent among the several contributing Standards Developing Organizations (SDOs) in the global community. HL7 standards are widely used and cover the full spectrum of applications. Its membership is international (currently including over 35 countries) and includes the major HIT vendors and representatives of the full set of stakeholders. The International Healthcare Technology Standards Developing Organization (IHTSDO) is rapidly promoting SNOMED CT as the preferred terminology in health care. While focusing on HL7 and SNOMED CT, Tim has included much useful information on other standards and other organizations. Readers will find this book easy to read, even if it is their first exposure to standards. In this rapidly changing field, this book is a must for anyone who is involved or has interest in the use of health information technology and who isn t. vii

8

9 Foreword to the Second Edition The success of this book validates the above remarks. Interoperability and the focus of the broad community on this topic and the implementation of systems and standards that support interoperability have grown at an exponential rate. As the implementation of Health Information Interchange systems grows, more and more people join the workforce to support this growth. They need to be taught and learn about standards supporting interoperability. I and a number of colleagues use this book as a text. The students love it it is clear and easy to read and understand. Technology and the ensuing standards to support standards change rapidly. In this second addition, Tim has astutely addressed this challenge. In some sections, he expanded the material; in others he reorganized the material; and, most importantly, he added new sections to increase the comprehension and coverage of the topic. The second edition is even better than the first. Durham, NC, USA W. Ed Hammond, Ph.D. Director, Duke Centre for Health Informatics Duke Translational Medicine Institute Duke University Associate Director, Biomedical Informatics Core Duke Translational Medicine Institute Professor, Community and Family Medicine Duke University Founding Member of HL7 (1987), Chair HL7 (1991, , ) ix

10

11 Preface Health information technology (HIT) promises to deliver the right information at the right time and the right place. Everybody (patient, clinician, manager, and payer) stands to benefit from more soundly based decisions, safer care, and less waste, errors, delays, and duplicated efforts. This depends on us using computers to share information and make it available when and where it is needed in a way that meets privacy requirements. We need to use appropriate standards to link systems together within and across organizations. Health Level Seven (HL7) and SNOMED CT are two of the key international standards, which underpin efforts to improve healthcare interoperability. HL7 provides the structure, rather like English grammar, while SNOMED CT provides words that computers can understand. This book provides an introduction to healthcare interoperability in general, and these standards in particular, setting out the core principles in a clear readable way for analysts, students, and clinicians to understand. The second edition of this book has been completely revised and extended by four chapters, with new chapters on Privacy and IHE XDS (Cross-Enterprise Document Sharing), clinical coding schemes, and the SNOMED Concept Model. The book is organized in three parts. The first part covers the principles of healthcare interoperability, why it matters, why it is hard, and why modeling is an important part of the solution. The second part covers the main HL7 standards: Version 2, Version 3, and CDA standards and related IHE profiles. The third part covers clinical terminology and SNOMED CT. xi

12

13 Series Preface In every industry, and healthcare is no exception, standards are the key to reuse, trust, and interoperability, leading to cost reduction and quality improvement. In healthcare, having information available in a trusted form, when and where required, leads to quicker and more soundly based clinical decisions and hence improvements in efficiency, safety and patient outcomes. The Office of the National Coordinator (ONC) for health information technology (HIT) has specified the standards to be used for electronic data interchange, clinical documents, terminology, privacy, and information security, in order for healthcare providers to qualify for incentive payments of over $35 billion. However, many of these HIT standards are complex and the barriers to adoption are now being addressed. The standards development organizations have recognized the need to introduce education on HIT standards into the higher education curriculum of both clinicians and HIT professionals. This series sets out to elucidate key HIT standards in a form that is accessible to both students and practitioners. The focus is on specific groups of standards and on how to use them individually and in combination. Usually, a single author who has been actively involved in the development, use, or teaching of these standards writes each book to provide a coherent viewpoint. Tim Benson xiii

14

15 About the Author Tim Benson graduated from the University of Nottingham as a mechanical engineer and was introduced to healthcare computing at the Charing Cross Hospital in London (now part of Imperial College Healthcare NHS Trust), where he evaluated the socioeconomic benefits of medical computing systems. In 1980, he founded Abies Informatics Ltd, one of the first GP computer suppliers where, with James Read and David Markwell, they developed the Read codes, which evolved to become the national standard for UK primary care and one of the two sources of SNOMED CT. In 1990, he led the first European project team to assess the need for open standards in health informatics, which led to the European Committee for Health Informatics Standards (CEN TC251) and two decades of work on interoperability standards and collaboration with HL7. For further information, see xv

16

17 Acknowledgments I am grateful to the many people who made useful comments on the first edition of this book. I want to thank in particular Dr. Mary Hawking to allow me to reproduce her story of Fred and his dog and to Dr. Malcolm Duncan for permission to reproduce the story of the Chocolate Teapot. Many people have contributed to my understanding of this healthcare interoperability HL7 and SNOMED. Dr. David Markwell, my friend and collaborator over 25 years, has made an outstanding personal contribution to both SNOMED CT and HL7. In the HL7 space, I want to thank and acknowledge my debt to Ed Hammond, Mark Schafarman, Jack Harrington, Clem McDonald, Woody Beeler, Charlie Mead, Bob Dolin, Mike Henderson, Abdul-Malik Shakir, Virginia Lorenzi and Réné Spronk, Charlie McCay, Leo Fogarty, Andrew Hinchley, Martin Whittaker, and Ann Wrightson. In clinical terminology, I have learned much from Alan Rector, Kent Spackman, Ed Cheetham, James Read, and Tom Marley. I would also like to thank Ed Conley, Pete Burnap, Roddy Neame, Justin Whatling, Sigurd From, Larry Weed, Georges de Moor, Seref Arikan, Michael Houghton, Timur Cevik, and David Ingram for their help in different ways. Finally, I wish to acknowledge all the great people who have made HL7 and SNOMED what they are today. This book includes copyright material on HL7 which is reproduced with the kind permission of HL7 International and on SNOMED CT, which is reproduced with the kind permission of the International Health Terminology Standards Development Organisation (IHTSDO); Health Level Seven and HL7 are registered trademarks of Health Level Seven International, Inc. IHTSDO, SNOMED, and SNOMED CT are registered trademarks of the International Health Terminology Standards Development Organisation. xvii

18

19 Contents Part I Principles of Health Interoperability 1 The Health Information Revolution... 3 Healthcare is Communication... 3 Information Handling... 6 Use of Information... 6 Clinical Decisions... 7 Lessons of History... 9 El Camino Hospital... 9 Problem-Oriented Medical Records Success in GP Surgeries Failure in NHS Hospitals The NHS National Programme Canada Denmark Meaningful Use References Why Interoperability is Hard Why Standards are Needed Electronic Health Records The Devil is in the Detail Complexity Creates Errors References Models The Importance of Models Models in Interoperability Standards Model-driven Architecture Life Cycle Scope xix

20 xx Contents Storyboards Requirements Specification Conceptual Design Technology-Specific Specification An Example: Colorectal Cancer Referral References UML and XML UML Class Diagrams Modeling Behavior BPMN XML XML Documents XML Elements XML Attributes XML Schema Namespaces Style Sheets XPath Reference Privacy Data Protection OECD Principles Information Governance Authentication Authorization Consent Management Cryptography Digital Signature Encryption Other Security Services References Standards Development Organizations What is a Standard? How Standards Bodies Work Standards Development Organizations (SDOs) HL7 International HL7 Products Ballot Process Membership The Technical Steering Committee IHTSDO IHE... 94

21 Contents xxi Continua Alliance CDISC OpenEHR Open Health Tools References Part II HL7 and Interchange Formats 7 HL7 Version Message Syntax Delimiters Segment Definition Segments Message Heavder MSH Event Type (EVN) Patient Identification Details (PID) Patient Visit (PV1) Request and Specimen Details (OBR) Result Details (OBX) Z-Segments A Simple Example Data Types Simple Data Types Complex Data Types Names and Addresses Other Complex Data Types HL7 V2 Tables HL7 V2 Documentation Further Reading The HL7 V3 RIM Origins Overview The RIM Backbone Common Attributes Act Entity Role Association Classes V3 Data Types Basic Data Types Instance Identifier (II) Code Data Types Dates and Times Name and Address Generic Collections

22 xxii Contents Special Fields Use of the RIM References Constrained Information Models Types of Model Types of Constraint Vocabulary and Value Sets Artifact Names A Simple Example RMIM Notation Tooling Templates Clinical Statement Pattern Relationships between Entries HL7 Development Framework Profiles Implementation Technology Specification (ITS) Documentation Clinical Document Architecture The Document Paradigm CDA History Header Patient Author Steward Other Participants Relationships Body Section Clinical Statement CDA Templates Continuity of Care Document (CCD) CCD Body greencda Reference HL7 Dynamic Model Interaction Trigger Event Application Role Message Type Interaction Sequence Message Wrapper

23 Contents xxiii Query Acknowledgement Safety IHE XDS Why XDS? XDS Metadata Document Data Patient Data Author Data Event Data Technical Data Submission Sets and Folders XDS Transactions and Extensions Point-to-Point Transmission Information Retrieval Security Profiles OpenExchange References Part III SNOMED and Terminology 13 Clinical Terminology Importance Coding and Classification Terminology Terms User Requirements Cimino s Desiderata References Coding and Classification Schemes International Classification of Diseases Diagnosis-Related Groups The Read Codes Hierarchical Codes Automatic Encoding Diseases Procedures History/Symptoms Occupations Examination/Signs Prevention Administration Drugs Development

24 xxiv Contents Why Read Codes Were Successful Problems SNOP and SNOMED LOINC UMLS References SNOMED CT Introduction Components The SctId Concept Description Relationships Expressions Precoordination Postcoordination Axis Modification Subsumption Testing Other Aspects Subsets Cross Mappings History Files Releases Documentation References SNOMED CT Concept Model SNOMED Hierarchies Attributes Object Hierarchies Clinical Findings Procedures Situations with Explicit Context Observable Entities Event Value Hierarchies Body Structure Organism Substance Pharmaceutical/Biologic Product Physical Object Physical Force Social Context Environments and Geographic Locations

25 Contents xxv Miscellaneous Hierarchies Qualifier Value Special Concept Record Artifact Core Metadata Concept Foundation Metadata Concept Linkage Concept Using SNOMED and HL7 Together Terminology Binding Model of Use Model of Meaning Structural Models Implementation Issues When to Use HL7 and SNOMED References Glossary Further Reading Index

26