National editions are published by a number of SNOMED International Members to customize the SNOMED CT International Edition to a specific country or territory. The table below lists some examples of Members who have published national editions of SNOMED CT. Please note that the International Edition is translated into Spanish. However, this translation is performed by SNOMED International, and is therefore not distributed as a national edition.
Table: Examples of national SNOMED CT editions
Australian edition
The table below lists some examples of published SNOMED CT editions and their included modules, as specified in the . Please note that a number of Members publish more than one edition. For example, in the UK both a national edition and clinical edition are published.
Table: Examples of national editions with their included modules
Edition
Included modules
The image below shows the four modules contained in the 20170901 US Edition, together with their module dependencies. Two of the modules are from the 20170901 US Extension, and the other two are from the 20170731 International Edition. Please note that the module dependencies (shown as grey arrows) are date specific, so each versioned source module is dependent on a versioned target module. The module names in this diagram have been shortened for brevity.
Table below: US Edition focus module and URI (for 20170901 US Edition)
Edition
Focus module
URI
The image below shows the five main modules in the 20171130 Australian Edition, together with their module dependencies. Two of the modules are from the 20170731 International Edition, and three are from the 20171130 Australian extension.
The table below lists the focus module and URI for the 20171130 Australian Edition.
Table: Australian Edition focus module and URI
Edition
Focus module
URI
The image below shows the eight modules contained in either the 20171001 UK Clinical Edition or the 20171108 UK Edition, together with their dependencies. The 20171001 UK Clinical Edition contains 4 modules, including two from the International Edition and two from the UK Clinical Extension. The 20171108 UK Edition contains eight modules, including two from the International Edition, two from the UK Clinical Extension and four from the UK Drug Extension.
The table below lists the focus modules and URIs for the 20171001 UK Clinical Edition and 20171108 UK Edition.
A SNOMED CT edition is a complete set of SNOMED CT components and reference set members that belong to an identified focus module plus all of the modules on which the focus module depends. Every SNOMED CT edition includes the contents of zero or more extension modules and the contents of the International Edition. The International Edition itself includes the contents of the | SNOMED CT core module| and the | SNOMED CT model component module| .
An edition consists of a set of modules (usually maintained by different organizations) that can be used as a standalone terminology solution within a healthcare environment. For this reason, many extension producers choose to publish their extension as an edition (which includes the content on which the extension depends), rather than as a separate extension. As explained in Packaging and File Naming, however, use cases exist for both packaging options.
The figure below illustrates the composition and dependencies of a local edition that is composed of a local extension module and the two international modules.
The composition of an edition is based on its module dependencies
The local edition consists of all components and reference set members that belong to the focus module and the two modules on which the focus module depends - | SNOMED CT core module| and the | SNOMED CT model component module| . As discussed previously, the version specific dependencies must be stated in the Module Dependency Reference Set.
There are many use cases that require a date specific version of an edition, including specifying the of a SNOMED CT query, and specifying the version of SNOMED CT used to code a specific data element in a health record. A versioned edition includes the contents of the specified version of the focus module, plus the contents of all versioned modules on which the versioned focus module depends (as specified in the ). The version of an edition is based on the date on which the edition was released. Many extension providers release their extensions as a versioned edition, using regular and predictable release cycles. For example, the International Edition is released by SNOMED International monthly.
Versioned editions can be identified using the using the following format:
where {sctid} represents the id of edition's focus module, and {timestamp} represents the release date of the edition. For more information, please refer to .
The table below shows some examples of versioned editions of SNOMED CT, with their corresponding focus module, URI and set of included modules.
Table: URIs for versioned editions of SNOMED CT
Edition
Focus module
URI
Included modules
Please note that a versioned edition is a logical composition of modules, and does not necessarily correspond to a single release package. For more information on release packages, please refer to and .
As discussed above, an edition is defined based on a single focus module. This focus module must be the most dependent module, in that the focus module is dependent on all the other modules in the edition. Note that the is always the least dependent module in all SNOMED CT editions, as it has no dependencies to other modules.
If a situation arises in which an extension has two equally dependent modules, then a new focus module may need to be created, with dependencies defined to all other modules in the edition. In this case, the focus module may contain only the components used to define the module concept itself and its dependencies as defined in the module dependency reference set. The image below illustrates a situation in which two (equally dependent) sibling modules exist - national module A and national module B - which are both dependent on the and the , and are not dependent on each other. To form a national edition, which contains both national module A and national module B, a new focus module must be created that is dependent on all other modules in the edition. The concept id of the new focus module is then used in the URI of the national edition that contains both national module A and national module B.
