Health Level Seven, Inc. (HL7) successfully balloted what it believes to be the first XML-based standard for healthcare— the Clinical Document Architecture (CDA). The CDA, which was until recently known as the Patient Record Architecture (PRA), provides an exchange model for clinical documents (such as discharge summaries and progress notes)—and brings the healthcare industry closer to the realization of an electronic medical record. The CDA Standard is expected to be published as an ANSI approved standard by the end of the year.

By leveraging the use of XML, the HL7 Reference Information Model (RIM) and coded vocabularies, the CDA makes documents both machine-readable—so they are easily parsed and processed electronically—and human-readable—so they can be easily retrieved and used by the people that need them. CDA documents can be displayed using XML-aware Web browsers or wireless applications such as cell phones, as shown by Nokia at the HIMSS 2000 demonstration.

The CDA is only the first example of HL7’s commitment to the advancement of XML-based e-healthcare technologies within the clinical, patient care domain. Along with the CDA, HL7 is developing XML-based Version 3 messages. These Version 3 messages enhance the usability of HL7 by offering greater precision and less optionality, conformance profiles that will help guarantee compliance, coded attributes linked to standard vocabularies, and an explicit, comprehensive, and open information model— the HL7 RIM. All this, packaged in a standardized XML syntax for ease of interoperability.

In 1999, HL7 also successfully balloted a recommendation for sending V2.3.1 messages using XML encoding. In 2001, HL7 will ballot, as a normative standard, a methodology for producing HL7 approved DTDs for Version 2.4 and previous versions.

"We want to dispel the notion that XML alone offers an alternative to HL7," said Stan Huff, chair of the HL7 board of directors. "XML is an encoding that complements the semantic content provided by the HL7 RIM, allowing users to exploit all the possibilities of the Internet. The extensibility inherent in XML is resulting in an explosion of schemas and DTDs from diverse sources, which actually decreases the ability to provide plug and play applications. The development of a model-based, standardized and industry-accepted application of XML, as provided by HL7, will help decrease the cost of integration, and improve the reliability and consistency of communications between disparate systems and enterprises."

HL7’s history with the Web and XML stretches back to the inception of the technologies. The organization is a long-standing and active member of the World Wide Web Consortium— the creators and keepers of XML. It has also exchanged sponsor memberships with OASIS, a non-profit, international consortium that operates XML.org, a global XML industry portal used to collect and distribute XML schemas.

About HL7

Founded in 1987, Health Level Seven, Inc. (http://www.HL7.org) is a not-for-profit, ANSI-Accredited Standards Developing Organization that provides standards for the exchange, management and integration of data that supports clinical patient care and the management, delivery and evaluation of healthcare services. Its 1,800 members represent over 400 corporate members, including 90 percent of the largest information systems vendors serving healthcare. HL7 international affiliates are active in Australia, Canada, China, Finland, Germany, India, Japan, Korea, The Netherlands, New Zealand, Southern Africa, Taiwan and the United Kingdom. HL7’s endeavors are sponsored, in part, by the support of its benefactors: Agilent Technologies, CAP Gemini Ernst & Young U.S. LLC, IBM Global Healthcare Industry, IDX Systems Corporation, IMRglobal, Johnson & Johnson, McKessonHBOC, Quest Diagnostics Inc., Shared Medical Systems (SMS) and the U.S. Department of Veterans Affairs.