HL7 Version 3 is used by healthcare computers to talk to other computers.
The name HL7 comes from 'Healthcare' and the top level (Level 7) of the Open Systems Interconnection (OSI) model, which carries the meaning of information exchanged between computer applications.
HL7 Version 3 is mainly used in large interoperability projects, such as the NHS Connecting for Health programme in the UK, Health InfoWay in Canada, etc.
HL7 V3 has significant differences from HL7 Version 2, which is mainly used within individual hospitals.
NEW: Meaningful Use and Beyond: A Guide for IT Staff in Health Care
- Are you ready to take your IT skills to the healthcare industry?
This concise book explains how the US healthcare system is implementing Electronic Health Records ("EHRs") and other IT systems to comply with the US government’s Meaningful Use requirements. A tremendous opportunity for tens of thousands of IT professionals, the Meaningful Use program requires a complete makeover of archaic paper records systems, cumbersome workflows and other outdated practices.
This book describes in detail how hospitals and doctors’ offices differ from other organizations that use IT and explains how to bridge the gap between clinicians and IT staff.
Electronic Health Records For Dummies
- a helpful, plain-English guide for doctors, nurses and healthcare administrators to understand, implement and use an Electronic Health Record system.
Health Care Information Systems: A Practical Approach for Health Care Management
- the Best Selling textbook in the field.
Mark Leavitt, MD, PhD, CCHIT Chairman said "With health care information technology now in the national policy spotlight, this book should be required reading for every health care administrator and student.
The HL7 CDA Book
- by eminent expert Keith Boone provides clear and easy-to-use CDA implementation guidance with numerous examples.
The reader will learn not only how to implement the CDA standard, but also to understand its idioms and to "speak" the CDA language.
Introduction to HL7 V2.x Messaging (2nd Edition)
- the most popular HL7 V2.x Messaging introductory Textbook. Mike Henderson is widely recognized as a most experienced HL7 V2.x teacher and trainer.
He regularly teaches at the HL7 Education Summits in the US and co-authors the HL7 V2.x Analyst Certification exams.
HL7 V2.x Messaging Study Guide
- the Study Guide to the above Textbook. Both books are considered mandatory reading and study for candidates sitting the HL7 International V2.x Analyst Certification exam.
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.
A specialised healthcare language is required to avoid the sort of ambiguity that is common in everyday medical English.
Computers cannot easily deal with synonyms (saying the same thing using different words) or homonyms (where the same term or phrase means different things depending on context).
Furthermore, healthcare data is uniquely complex in scope and structural complexity.
Joined-up healthcare is difficult when patients have multiple problems and are being treated by several specialists in different locations.
HL7 and XML
HL7 messages are XML documents, which look somewhat similar to HTML.
Each message is a string of text with information enclosed by tags, wrapped in angle brackets.
Start tags look like <tag> and end tags look like </tag>.
Tags can be qualified by attributes such as <tag attribute="value">.
The HL7 tags and attributes are derived from the HL7 Reference Information Model (RIM) and the HL7 Data Types.
The structure of each HL7 message is set out in an XML schema, which specifies the tags and attributes needed or allowed in the message, their order and the number of times each may occur, together with annotations describing how each tag shall be used.
The HL7 RIM Reference Information Model
HL7 is a language, and every language has a
grammar. The HL7 RIM (Reference Information Model) specifies the grammar of HL7
messages and, specifically, the basic building blocks of the language and their
permitted relationships. The RIM is not a model of healthcare, although it is
healthcare specific, nor is it a model of any message, although it is used in
messages. At first sight the RIM is quite simple. The RIM backbone has just five
core classes and a number of permitted relationships between them.
In HL7 V3, every happening is an Act, which is
analogous to a verb in English. Each Act may have any number of Participations,
in Roles, played by Entities. These are analogous to nouns. Each Act may also
be related to other Acts, via Act-Relationships.
Act, Role and Entity classes also have a number of
specialisations. For example, Entity has a specialisation called Living Subject,
which itself has a specialisation called Person. Person inherits the attributes
of both Entity and Living Subject.
RMIM Refined Message Information Model
HL7 has developed a notation, called Refined Message Information Model (RMIM), which displays the structure of a message as a
colour-coded diagram. Most RMIMs can be shown on a single sheet of paper or
PowerPoint slide and these RMIM diagrams are used to design messages and to
explain what each HL7 message consists of.
Structural Attributes
Structural attributes are used to specify more
precisely what each RIM class means when used in a message. For example, Act has
a class code and a mood code. The class code states what sort of Act this is,
such as an observation, an encounter, or the administration of a drug. Mood is
analogous to the tense of a verb. Mood code indicates whether an Act has
happened (an event), or is a request for something to happen, or a goal or even
a criterion. For example, "weight = 100kg" is an observation event; "measure
weight daily" is a request; "reduce weight to 80Kg" is a goal and "if weight is
greater than 80Kg" is a criterion.
Attributes and Data Types
The RIM defines a set pre-defined Attributes for each class and these are the only ones allowed in HL7 messages.
Each attribute has a specified Data Type. These Attributes and Data Types become tags in HL7 XML messages.
Refinement
Message specifications, to do a particular task, use a sub-set of the available RIM Attributes, listing each element used and how
many repeats are allowed. This is known as refinement. Each Data Type is constrained to the simplest structure that meets the requirements of the task.
Identifiers and Codes
One common data type is the Instance Identifier, which is used to give unique identity to people, persons, organisations, things and information objects.
HL7 uses two main types of code. The first type covers the specialised codes used for structural attributes and are defined by HL7 itself.
The second type covers externally defined terms and codes such as SNOMED CT (Clinical Terms).
Scope and Extensibility
HL7 covers the whole scope of healthcare communications in an unambiguous way, using a relatively small set of constructs, which need to be learnt.
Healthcare communications are complex and any language needs to accommodate this complexity and also handle future needs.
Didn't find what you were looking for? Try the HL7 Search Engine:
HL7 Technical Newsletter
Keep up-to-date with the "HL7 TechNews" Technical Newsletter on Health Level 7 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:
NOTICE: All of the tools available thru
this page are designed to support the development and publication of
HL7 Version 3 Messaging standards. These tools carry a license that
restricts their use to activities that support the development and
implementation of standards by members of HL7 and of the HL7
International Affiliate organizations.
NOTICE:This release was assembled to reflect the tools that should be used for preparing Ballot 2007May.
The Tooling Committee will keep these tools stable throughout the
period, and will release required updates only in the case that a
serious bug affecting users content is found.
Detailed
documentation of HL7-supported tools, including their architecture,
functions, inter-relationships, strengths and weaknesses. Prepared
for Tooling Committee.
Installs a
Publication DB and necessary support files. VB code in the Pub DB
will invoke WYSIWYG editing of the XML markup using XML Spy Suite
4.4 or 5.0 Supports local publication of domain content. Requires
CURRENT RoseTree. User Guide included. Be sure to 'remove' or uninstall the
previous version before installing this one.
The previous pubDb
release is provided to facilitate migrating data older than PubDb
release 201.
The Pub DB Manager
is a widget created to facilitate the alignment of artifact status
and topic content across PubDbs and Design repositories, and the
merger of PubDbs, both across domains and within a domain. Its
primary focus is for internal use in publishing HL7 ballots.
The Description
Editor is a component of the Pub Db that can be installed separately
to support editing of descriptive text for HL7 ballots. Do not install this
if RoseTree and/or the PubDb are already on your system. It is
installed as part of those packages and a separate installation will
cause conflicts. User Guide included.
This Access
database holds consolidated data from V3 Ballot Reconciliation
Spreadsheets. The data span ballot cycles '2005jan' through
'2006may' and include all reconciliation sheets uploaded through
5/15/2006.
The DB includes
software for batch import of data from new spreadsheets, and limited
documentation on the use of this.
Version 3 Static Model Design & Documentation Tools
Contents: This is an
intelligent installer for the HL7 R-MIM design templates for
interactive design with Visio 2000 or 2002. These tools do not work with Visio
2003 (See
advisory).
This tool requires
a
Design/RIM Repository (below) and the installation of RoseTree
(below) to function. The installer includes instructions for
installation and use of these tools. This is the latest
"official" release.
May be updated based on data from Committees as CMETs change
status. CMETinfo.txt file
is used by the RMIM design tools (in Visio) to specify the CMETs
that may be included in a design. This file should be downloaded
and placed in your Visio "Solutions\HL7" directory if it is more
recently released than the Visio RMIM Designer tools
Formal naming in
the RMIM designer can be updated independently from the Formal
Naming Source file. Installation instructions are on a ReadMe in the
archive.
This release of 1/14/2007 does not contain all vocabulary changes
approved at Harmonization in November 2006. To meet the needs of
TCs that require this daya, there will be a later repository release
when these changes are available.
The
most recent HL7 Model Repository for capturing message designs.
Includes the most recent RIM and Vocabulary. This is updated as
additional columns and tables are added to the repository.
Note: Use of this
design repository with the RMIM Designer (in Visio) or with other
RoseTree-supported applications requires RoseTree Version 3.0.0
or later.
The archive also
holds the latest formal naming source file for the RMIM Designer in
Visio. This source file can also be
downloaded separately.
Contents:
This is the most current release of RoseTree, which builds R-MIMs
and HMDs for the Version 3 demonstration. This will INSTALL
RoseTree.exe on your system, works with the published, R-MIM-enabled
repository. It will also install Microsoft's MSXML4 (if this is not
already on your machine) to perform XML extracts from Repository. Be sure to 'remove' or uninstall
the previous version before installing this one.
The HL7 Model Interchange Format (MIF)
defines a series of schemas for XML files that will hold
the content of HL7 Version 3 specifications. These files will be
the foundation for HL7 Version 3 Tooling in the future when all HL7
supported tools will use MIF-based files as their source of data and
will emit MIF-based files as their output. (See
tools documentation.)
A subset or replacement of the Generator will be release near the
end of January 2007 to support "desktop" publishing of Static Model
TableViews.
HL7 3 Generator (requires Java
Runtime 1.4.2) is a successor to the Schema Generator. It
takes XML representations of RIM, Vocabulary, HMDs, etc. and
"generates" MIF files, Schemas, Table Views and Excel views. Use of
this Generator requires source files distributed separately (see
following entry). Extract the files from the ZIP file, preserving
the directories. Instructions are in the "HL7 Version 3.htm" file
which is installed in "documentation" directory.
Additional source
files (Domain HMDs and domain dynamic models) for use with the
Generator software.
Source files are
posted from a particular ballot cycle. See the release notes on the
Gforge downloads to determine which ballot was used for a particular
release..
'; break; }
case 2: {
/* Mozilla: Firefox */
echo '';
echo '
'; break; }
case 3: {
/* ClickBank: RealWritingJobs */
echo '';
echo '
'; break; }
case 4: {
/* Sedo */
echo '';
echo '
'; break; }
case 5: {
/* Crazy Domains */
echo '';
echo '
'; break; }
case 6: {
/* GoDaddy */
echo '';
echo '
'; break; }
case 7: {
/* SmartHome */
echo '';
echo '
';
echo '
'; break; }
}
?>
; ?>20&l=ur2&o=1 "HL7 Book"){kind=small}
to learn the Secrets of Health Level 7.
