The HL7 Clinical Document Architecture

Abstract

Many people know of Health Level 7 (HL7) as an organization that creates health care messaging standards. Health Level 7 is also developing standards for the representation of clinical documents (such as discharge summaries and progress notes). These document standards make up the HL7 Clinical Document Architecture (CDA). The HL7 CDA Framework, release 1.0, became an ANSI-approved HL7 standard in November 2000. This article presents the approach and objectives of the CDA, along with a technical overview of the standard. The CDA is a document markup standard that specifies the structure and semantics of clinical documents. A CDA document is a defined and complete information object that can include text, images, sounds, and other multimedia content. The document can be sent inside an HL7 message and can exist independently, outside a transferring message. The first release of the standard has attempted to fill an important gap by addressing common and largely narrative clinical notes. It deliberately leaves out certain advanced and complex semantics, both to foster broad implementation and to give time for these complex semantics to be fleshed out within HL7. Being a part of the emerging HL7 version 3 family of standards, the CDA derives its semantic content from the shared HL7 Reference Information Model and is implemented in Extensible Markup Language. The HL7 mission is to develop standards that enable semantic interoperability across all platforms. The HL7 version 3 family of standards, including the CDA, are moving us closer to the realization of this vision.

A standard XML Schema for computerised anaesthetic records

“…Work toward the development of XML schemas for a range of medical document classes (e.g. referral letters to general practitioners and hospital discharge summaries) is already underway [13,14]. Reference information such as drug formularies, clinical guidelines, journal articles and equipment manuals will also be delivered in XML.…”

“…The level of detail of information structuring should be as high as possible, with the caveat that in some circumstances it may be appropriate for the schema to support alternative levels of detail (for example, when recording a patient's regular medication as part of preanaesthetic assessment, it may be appropriate for the schema to offer both a coarse-grained and a fine-grained representation. Where appropriate, the design of the schema should facilitate interoperability with other schemas, for example, government standards for representing demographic information in educational and social domains, and national or international standard schemas pertinent to related clinical domains (such as schemas for clinical investigation reporting [13,14]). Although the schema should be freely available, there should be a mechanism for controlling its distribution and maintenance.…”

Extending document models to incorporate semantic information for complex standards

“…The closest related area of research is the Health Level 7 Clinical Document Architecture (CDA) framework [13,14,15,16]. The framework has two core parts, the Clinical Document Architecture (CDA) and the Reference Information Model (RIM).…”

Improving the Usability of HL7 Information Models by Automatic Filtering

“…In our current prototype, the time required for this computation is about 2 seconds. On the other hand, to compute the closeness Ω(c, FS) of an HL7 class with regard to the focus set FS it is required to know the minimum distances between classes in the HL7 models (see (2) in Section IV). However, it is only necessary to compute the distance from each class in the focus set to any class out of FS, which requires a lower computational cost.…”

“…The HL7 standard specifications are unified by shared reference models of the healthcare and technical domains [2], [3].…”