Health Level 7 (HL7) is an international standard national development organization established more than 20 years ago.¹ HL7's key subject is the integration of clinical and administrative data. It creates standards for the exchange, management, and integration of electronic healthcare information. It also develops specifications, for example a messaging standard that enables disparate healthcare applications to exchange key sets of clinical and administrative data. It is accredited by the ANSI (America National Standards Institute and houses its headquarters in Ann Arbor, Michigan. HL7 is also a not for profit organization whose members contribute based on a strict volunteer basis. The organization (like so many others) aims to become the finest and most widely used standard in the health care industry dealing with health informatics. Today, HL7 affiliate organizations exist in more than 40 countries. Hospitals and other medical institutions typically use many different types of systems to communicate with one another. Everything, from patient records to billing information, is tracked and recorded in computer systems. In order for these different types of systems to communicate with each other, they use a standard like HL7.

HL7 creates healthcare standards to enable interoperability of healthcare information (HL7 does not create or provide any sort of software). This way, messages and documents move healthcare information in a standardized way to the point of patient care. Standards assist in moving information within and beyond the four walls of hospitals and clinics among all healthcare stakeholders, they assist in the sharing of public health information, and they help enable the electronic health record and creation of a National Health Information Network (NHIN). HL7 does not create or provide any sort of software. It does provide healthcare organizations with specifications for making their systems interoperable. HL7 develops coherent, extendible standards and a formal methodology. This allows collaborating with healthcare information users and other standards development organizations, which in turn promotes the use of HL7 standards worldwide. There are several health care standards development efforts currently underway throughout the world. HL7 is singular as it focuses on the interface requirements of the entire health care organization, while most other efforts focus on the requirements of a particular department. Moreover, on an ongoing basis, HL7 develops a set of protocols on the fastest possible track that is both responsive and responsible to its members.

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. Collectively, the co-chairs comprise the Technical Steering Committee, which votes on issues related to the standard. Votes of the Technical Steering Committee are passed as recommendations to the Board of Directors, who make the final decision. HL7 members are encouraged to participate in all of these committees. Like many other organizations, HL7 has undergone many changes and uses a system of "versions" much like software or hardware systems and infrastructures. Version 3 represents a significant departure from "business as usual" for HL7. Offering lots of options and thus flexibility, the V2.x series of messages were widely implemented and very successful. These messages evolved over several years using a "bottom-up" approach that has addressed individual needs through.
"Level Seven" refers to the highest level of the International Organization for Standardization (ISO) communications model for 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.

Applications (Standards)

There are several HL7 Standards. The most common are the Version 2.x and Version 3 Messaging standards, and the Arden Syntax. Version 2.x Messaging Standard is an interoperability specification for transactions produced and received by computer systems. These specifications are published as a collection of chapters that describe the transaction interactions by domain. Version 3 messages include the concepts of message wrappers, sequential interactions, and model-based message payloads.²
The Arden Syntax allows to implement rules into healthcare computer systems. These rules are independent of the computer system in use. It processes medical conditions and gives recommendations as a module, which will further be used in medical alrogithms.

Other HL7 standards include:
  • Version 3 Rules/ GELLO
  • CCOW/ Visual Integration
  • Claims Attachments
  • Clinical Document Architecture (a V3-based standard)
  • HL7 Electronic Health Record/ Personal Health Record
  • Structured Product Labeling (a V3-based standard)

Web Resources

Official HL7 web site

HL7 101: A Beginner's Guide

HL7 Information

HL7 Introduction Guide

Everything You Need To Know About HL7

Related Terminology

Arden Syntax
Clinical Context Object Workgroup - CCOW
National Health Information Network - NHIN

Citation/ References



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