HL7 Introduction, Guide and FAQ

Introduction to HL7

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This page provides a simple, practical and easy-to-follow introduction to the Health Level 7 ("HL7") Standards. History, uses and how they are created are explained as well as the difference between "V2.x", "V3" and "XML" explained and how the CDA ("Clinical Document Architecture") Standard fits in.

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What is Health Level 7 (HL7)?

What is HL7? A Simple Introduction ...

Just as people from different countries with completely different native tongues are only able to communicate with each other if they can speak a common language, computer applications can only share information if they communicate with a common protocol. For people or computers to be able to share clinical data with one another, they must both:

have functions to be able to physically communicate, e.g. speak & hear, send and receive documents and data files, share data and information. This is called "functional interoperability".
speak a common language (in terms of nouns, verbs, grammatical structure, etc.) and share the same vocabulary that allows them to understand complex medical conditions and processes. This is called "semantic interoperability".

A group of healthcare computer systems users started developing the HL7 protocol in 1987 to create a common "language" that allows healthcare applications to share clinical data with each another. Over time the HL7 interoperability protocol became a nationally, internationally and globally accepted and accredited standard.
The term "Health Level 7" ("HL7") is used both for the organisations involved in developing and supporting the healthcare standards as well as for the Version 2.x and Version 3 Standards themselves and other standards developed by the HL7 local organisations in ~30 countries. HL7 creates international standards for inter-system and inter-organisation messaging, for decision support, clinical text document mark-up,

user interface integration as well as a health data model and a message development methodology.

HL7 Books we Recommend:

Introduction to HL7 V2.x Messaging (2nd Edition) - a very popular introductory book

HL7 V2.x Messaging Study Guide - the Study Guide to the above textbook.

Principles of Health Interoperability HL7 and SNOMED - Healthcare depends on the two leading standards HL7 and SNOMED CT for functional and semantic interoperability. Tim is one of the most experienced teachers of both HL7 V3 and SNOMED CT.

HL7 CDA: the Missing Link in Healthcare IT - an important article from "Health Management Technology"

Managing Health Care Information Systems: A Practical Approach for Health Care Executives - the title says it all...

E-Health Care Information Systems: An Introduction for Students and Professionals - excellent

Verification Results for IT Standards: HL7 - a reader focussing on the formal verification of standards

More HL7 Books and Manuals to learn the secrets of Health Level 7.

What does the Name "HL7" mean?

HL7 International's Vision is "To create the best and most widely used standards in healthcare"
HL7 International's Mission is to provide standards for interoperability that:

improve care delivery
optimise workflow
reduce ambiguity

enhance knowledge transfer

What does HL7 International do?

A frequent misconception is that Health Level Seven develops software. In reality, HL7 develops specifications, the most widely known being a messaging standard that enables disparate healthcare applications to exchange clinical and administrative data.
Members of Health Level Seven are known collectively as the Working Group, which is organized into Technical Committees (TCs) and Special Interest Groups (SIGs). The technical committees are directly responsible for the content of the Standards. Special interest groups serve as a test bed for exploring new areas that may need coverage in HL7’s published standards. A list of the technical committees and special interest groups as well as their missions, scopes and current leadership is available on the HL7.org web site.
Recent years have seen a move toward an increasingly global HL7. From 9 Affiliates in 1999, HL7 has grown to ~30 international affiliates in 2006. Currently, the worldwide membership is over 4,400. The global scope also involves increased collaboration with other regional and international standards organizations, such as CEN in Europe and the International Standards Organisation (ISO). HL7 has achieved ISO status for its standards and is moving toward harmonization with the CEN standards.
The HL7 organisation has formal relationships with other major Standards Development Organisations (SDOs), including:

ASTM (American Society for Testing Materials)
CEN TC/251 (Europe)
DICOM (Digital Imaging and Communication in Medicine)
IEEE (Institute for Electrical and Electronic Engineers)
OASIS
OMG (Object Management Group)

The full list of organisational relationships and agreements can be viewed here.
All standards and documents produced by HL7 are protected under copyright law (see "Do I need a licence to use HL7" below).

Read HL7 Books and Guides to learn the secrets of getting the most out of HL7.

What does the Name "HL7" mean?

"Level Seven" refers to the top level of the seven-layer International Standards Organization's (ISO) communications model for Open Systems Interconnection (OSI) - the application layer. The application level addresses definition of the data to be exchanged, the timing of the interchange, and the communication of certain errors to the application. The seventh level supports such functions as security checks, participant identification, availability checks, exchange mechanism negotiations and, most importantly, data exchange structuring. (More info on the 7-layer ISO communications model at: http://en.wikipedia.org/wiki/OSI_model.)
HL7 focuses on the interface requirements of the entire health care organization, while most other efforts focus on the requirements of a particular department. HL7 undertakes ongoing development of protocols on the fastest possible track that is both responsive and responsible to its members. The group addresses the unique requirements of already installed hospital and departmental systems, some of which use mature technologies.
While HL7 focuses on addressing immediate needs, the group continues to dedicate its efforts to ensuring concurrence with other United States and International standards development activities. Argentina, Australia, Bulgaria, Canada, China, Czech Republic, Finland, Germany, India, Japan, Korea, Lithuania, The Netherlands, New Zealand, Southern Africa, Switzerland, Taiwan, Turkey and the United Kingdom are part of HL7 initiatives. Moreover, HL7 is an American National Standards Institute (ANSI) approved Standards Developing Organization (SDO). HL7 strives to identify and support the diverse requirements of each of its membership constituencies: Users, Vendors, and Consultants. Cognizant of their needs, requirements, priorities and interests, HL7 supports all groups as they make important contributions to the quality of the organization. The committee structure, balanced balloting procedures and open

membership policies ensure that all requirements are addressed uniformly and equitably with quality and consistency.

More Info:

How is HL7 organised?

The organization is managed by a Board of Directors, which is comprised of eight elected positions and three appointed positions. The organization is comprised of Technical Committees and Special Interest Groups that are responsible for defining the HL7 standard protocol. Each Technical Committee and Special Interest group is chaired by two or more co-chairs. The TCs and SIGs are grouped into Steering Divisions, which comprise the Technical Steering Committee, which votes on issues related to the standard. The Board of Directors has strategic oversight over the TSC.

HL7 members are encouraged to participate in all of these committees.

Who is Health Level Seven International?

HL7 Norway - Why are we an HL7 Affiliate?

Health Level Seven International is one of several ANSI-accredited Standards Developing Organizations (SDOs) operating in the American healthcare arena. Most SDOs produce standards (sometimes called specifications or protocols) for a particular healthcare domain such as pharmacy, medical devices, imaging or insurance (claims processing) transactions. Health Level Seven’s domain is clinical and administrative data.
Headquartered in Ann Arbor, USA, Health Level Seven is a not-for-profit volunteer organization - like most of the other SDOs. Its members - providers, vendors, payers, consultants, government groups and others who have an interest in the development and advancement of clinical and administrative standards for healthcare - develop the standards. Like all ANSI-accredited SDOs, Health Level Seven adheres to a strict and well-defined set of operating procedures that ensures consensus, openness and balance of interest.

For more information on HL7 (USA) see the "About HL7" page on the HL7.org web site! For answers to frequently asked questions on HL7 (USA), see the "HL7 FAQ" page on the HL7.org web site! View the latest HL7.org Newsletters, the HL7.org Press Releases and the HL7.org Press Release Archive.

Read HL7 Books and Guides to learn more about HL7.

What happens at an HL7.org Working Meeting?

HL7 is organized around Technical Committees (TCs) and Special Interest Groups (SIGs). These committees are responsible for defining the HL7 Standards. TCs are responsible for at least one chapter in one of the HL7 Standards, while SIGs work closely with TCs to ensure that information within their particular domain is considered and represented in the Standards. Two or more co-chairs, who develop meeting agendas and ensure that the work of the group proceeds as scheduled, chair each TC and SIG. The TCs and SIGs are represented in four Steering Divisions which in turn constitutes the Technical Steering Committee (TSC).

What goes on at an HL7 Working Meeting?

You will be able to quickly identify Board and TSC Members at the meeting by the ribbons on their name badges. TC and SIG meetings are held throughout the week, are open to all meeting attendees and are informal in nature, so don't be afraid to simply show up and get involved!

HL7 Mentors and Staff are onsite during the week; so don't hesitate to stop by should you have a question.

HL7 offers a very useful First Timers Attendees Orientation which is held both on Sunday evening and on Monday morning. Also, look for the "First Time Attendee" designated lunch tables on Monday and Tuesday to meet with other first-time attendees and seasoned members who have volunteered to help you learn the ropes.
Each day, the HL7 Working Group Meeting begins at 8:30 a.m. with an informative general session for announcements and dissemination of general information such as changes in meeting rooms and/or times. Technical Committees (TC), Special Interest Groups (SIG) and tutorials begin following the general session.
HL7 Working Group Meetings always provide a vast array of educational opportunities. Over 20 tutorials are scheduled for the Working Group Meeting on topics such as Implementing HL7, V2.x, V3, XML, CDA and HL7's Vocabulary initiatives. Please refer to the Working Group Meeting Brochure for course descriptions.

Go to the First-Timers HL7 web page for info to prepare you for your first Working Group Meeting experience.

Who is "HL7 Australia"?

HL7 Australia is an open, volunteer-based, not-for-profit organisation that supports the needs of HL7 users in Australia. HL7 Australia is the local HL7 user group and the accredited national affiliate of HL7 Inc. (USA). It has local responsibility for a range of core activities including the distribution and licensing of the HL7 Standards materials, education, user support and certification of professionals and systems. Copies of the HL7 standards can be purchased from HL7 Australia; substantial discounts are available to HL7 Australia Members.

For more information see the HL7 Australia web site.

What about the HL7 Decision Support Standards?

Ross Martin provides an introduction to the GELLO (Guideline Expression Language) and recently developed open source implementation tools.

More Videos at www.HL7.tv

Do I need a License to use the HL7 Standards?

As HL7 is a not-for-profit public-good organisation (as are its local organisations, the "Affiliates"), its products - the HL7 Standards - are essentially freely available and can be used for free. As such, there are no usage licenses required or license fees payable when using the HL7 Standards to implement interfaces.
However, to ensure that the HL7 Standards are not inappropriately modified or abridged, they underlie a strict copyright. As a result, if a substantial part of any HL7 Standards document is to be used in any commercial or non-commercial products or services (paper or electronic manuals, interface engines, educational materials, etc.), an appropriate license must be obtained from HL7 or its Affiliates. The Affiliates manage the HL7 intellectual property ("IP") rights in their respective territories. Additionally, as HL7 levies a small fee on copies of the standards it provides (similar to the "distributions" of Linux, Apache, Open Office or other free software) the unauthorised distribution of the standards is not legal. However, some older versions (eg. HL7 V2.3.1) of the Standards can be downloaded for free.

The HL7.org Copyright Policy (2000) states:
As an ANSI-accredited standards developer for health care related electronic data interchange, HL7 is responsible for assuring that the Standards remain accurate and their integrity is maintained. This duty is consistent with the mandate of a standard making organization to assure that the emerging standard is consistently presented and its evolution fully documented. Copyright secures to its owner the exclusive right to authorize certain uses of the copyrighted material. HL7's objective in asserting and enforcing copyrights in the Standards is to assure that the public and end-users of the Standards may rely upon HL7 to be an official source of the most current and accurate versions of the Standards. To achieve the twin objectives of 1) assuring the integrity of the Standards, and 2) guaranteeing that users may secure from a reliable source a verified version of a particular standard, HL7 has and will continue to enforce the copyrights it holds in the Standards. As dissemination and implementation of the Standards continues, it is imperative that HL7 have a method to assert and enforce its role to maintain the official editions of the Standards. Copyright provides this enforcement and protection mechanism.

In summary:

HL7 is a volunteer, not-for-profit organisation; distribution fees and membership fees support its operation.
The HL7 Standards can be freely implemented; no licenses or license fees are required.
The HL7 Standards underlie a strict copyright; unauthorised copying is not permitted.
Use of the Standards within organisations that are HL7 Members is fine.
The copying of substantial parts (>10%) of the Standards for commercial or educational purposes requires a license agreement.

Read HL7 Books and Guides to learn the secrets of getting the most out of HL7.

HL7 TechNews Technical Newsletter

Keep up-to-date with the "HL7 TechNews" newsletter on technical and tooling developments! It will give you regular updates on all technical HL7 matters around the globe, in particular new standards developments and tooling releases.

HL7 News

January 2011 HL7 International Working Meeting to be held in Sydney, Australia
Monday, 21st June 2010
The January 2011 Working Meeting of the HL7 International standards organisation will be held in Sydney, Australia. Scheduled for 9-14 January 2011, the Working Meeting will provide the forum for more than 50 Work Groups, Committees and Task Forces to progress the HL7 V2.x, CDA, V3 and EHR Standards. An extensive range of Courses, Tutorials and Workshops will allow Australians to hear and learn the very latest developments in EHRs, clinical messaging, terminology, etc. from the global experts and leaders in e-health. To host the Working Meeting in Sydney, HL7 Australia has partnered with the Dept of Health and Ageing, NEHTA, Standards Australia, HL7 New Zealand and Business Events Sydney (NSW Govt.). The Australian e-Health community is delighted to welcome the e-health standards world to Sydney in January and is looking forward to an exciting and productive meeting.

HL7 International Working Meeting Information
Sunday, 16th May 2010
Information on the Work Group activities at the HL7 International Working Group Meeting in Rio de Janiero, Brazil, is now collated in one convenient location on the HL7 Wiki. Apart from general WGM information, the agendas and meeting papers of most committees are available for review and download.

HL7 International May 2010 Working Meeting Rio de Janiero, Brazil
Monday, 3rd May 2010
HL7 International will hold its upcoming May Working Group Meeting in Rio. The WGM is preceeded by an ISO TC215 Plenary Meeting as well as an International HL7 Implementation Conference (IHIC).