Health Level Seven (HL7): More Than Just Messages

Abstract Title: Health Level Seven (HL7): More Than Just Messages
Authors: David John Marotta
DT7 Software, L.L.C.
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Health Level Seven


Health Level Seven, Inc. demonstraded prototype Version 3 messaging and the XML Patient Record Architecture at the 1999 HIMSS Conference, February 21-25, 1999. The HL7 XML architecture represents the latest developments in a standardization effort built on years of real-world implementation experince. Increased precision and interoperability, integrated documents and messages, and reduced implementation costs are but a few of the benefits derived from HL7's latest efforts.

The HL7 Clinical Context Management (CCM) Specification by the Clinical Context Object Workgroup (CCOW) allows clinical applications to couple, coordinate, and synchronize their clinical context at the point-of-use.

The first HL7 standard to address interoperability at the point-of-use (front-end) is the Clinical Context Management (CCM) Specification. An ANSI-approved American National Standard, the CCM Specification is a protocol for visually integrating clinical desktop applications. At the core of this specification are the Patient Link and User Link Standards.

Patient Link enables users to select the patient of interest from any application, as the means to automatically "tune" all of the applications to the same patient. Similarly, User Link grants users access to a range of applications, but only requires them to sign on once. The specification include a high level architecture that is technology-neutral as well as mappings to specific target technologies such as Active-X.

The CCM's reliance on component technology allows vendors to quickly incorporate this standard into their products or re-engineer their systems to be compliant, enabling them to maintain focus on their core competency. Providers benefit by the improved workflow efficiencies and productivity gained from quicker access to information. And, since CCM enabled applications are easier to use, they encourage clinicians to use the full breadth of their systems' functionalities, a significant benefit to vendors and providers alike.

HL7 has recently announced the availability of new version of The Arden Syntax for Medical Logic Systems. This ANSI-approved American National Standard is a language for representing and sharing medical knowledge among personnel, information systems and institutions and designed for organizations that require or develop systems that automatically assist physicians in decisions and alerts.

The logic for making these decisions or issuing these alerts is encoded into health knowledge bases called Medical Logic Modules (MLMs) each of which contains sufficient knowledge to make a single decision. Contraindication alerts, management suggestions, data interpretations, treatment protocols, and diagnosis scores are examples of the health knowledge bases that can be represented using the Arden Syntax.

HL7's Electronic Patient Record Architecture (PRA) is a comprehensive architecture for the exchange of XML clinical documents in conformance with the HL7 RIM and using complexity with a common docuemtn structure and metadata applied across all levels. Level One of the architecture and the PRA header are being prepared for ballot and early implementation. This presentation review the conceptual and technical basis for this scalable exchange specification and its application to diverse domains of healthcare information.

Presenter's Biography:

David John Marotta () gained his undergraduate degree from Stanford, and his Masters in Computer Science from the University of Oregon. Marotta taught Computer Science before moving to the University of Virginia Health System in 1990. In 1999 he became the President of DT7 Software, which provides clinical information systems and integration software and consulting. He lectures and instructs for conferences, including Health Level Seven (HL7). His resume is available on line at