Introduction

This Terminology Fundamentals guide describes the basic principles of terminology that are used and described across HL7 published standards. Terminology Fundamentals highlights terminology basics previously published in HL7 standards while maintaining a product family agnostic approach. It is intended to serve as an educational reference for those wishing to learn more about terminology across HL7, but it is not intended to provide implementation specific guidance, as other resources exist for that purpose.

HL7 Terminology

Terminology (often referred to as Vocabulary) describes the structured data for clinical and administrative information that can be recorded and exchanged in HL7 specifications.

In HL7, the possible values for data elements and the associated meanings of those values are defined in Code Systems, from which both the Concept Representation and any associated meanings are drawn. The set of codes that are allowed for a particular coded model element is referred to as a Value Set.

The pages included under the Terminology Artifacts tab describe the structural properties of terminology artifacts, such as Concepts, Code Systems, Value Sets, and more. The Characteristics of a Value Set Definiton tab includes pages that describe the data elements that formally define and characterize how to create an HL7 conformant Value Set. For more information on the sources that the information was drawn from, please see the Background page.

The Rationale - Semantic interoperability

In HL7's view, interoperability requires that the systems be able to "exchange" information reliably and securely ("functional interoperability") and be able to correctly and consistently interpret the information being exchanged ("semantic interoperability"). Terminology plays a huge role in enabling semantic interoperability.

In the 21st Century, "functional interoperability" is increasingly easy to accomplish. what with the availability of carefully integrated computational and communication environments in which to implement. "Semantic Interoperability," however, poses major challenges, particularly for the enterprise of health care in which:

• the intellectual space continues to expand so rapidly that most individuals cannot keep pace;

• the interpretation of any given data element is inexorably linked to the context in which that element was discovered, and the whole of the other data about the same subject;

• the data content requires precise, and frequently extensive scientific representation;

• a large, fraction of the data encoded in rich terminologies that are both vast, and continually expanding; and

• human life and well-being depend upon the rapid, correct interpretation of the information.

Dependencies

This guide is based on the FHIR R5 specification. In addition, this guide also relies on a number of parent implementation guides:

This implementation guide defines additional constraints and usage expectations above and beyond the information found in these base specifications.

Intellectual Property Considerations

This implementation guide and the underlying FHIR specification are licensed as public domain under the FHIR license. The license page also describes rules for the use of the FHIR name and logo.

No use of external IP