Introduction

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Te Whatu Ora - Health New Zealand works with health agencies and their industry partners to develop SNOMED CT® reference sets, maps, language reference sets and other content for digital health solutions in Aotearoa New Zealand.

The SNOMED CT New Zealand Extension packages these components for release every April and October, to be used with the latest designated SNOMED CT International Edition release.

The content can be downloaded from our member licensing and distribution service, viewed online using the SNOMED CT browser or accessed via FHIR® API using the NZ Health Terminology Service. 

We welcome your feedback and participation. For more information about SNOMED CT implementation in New Zealand, see our website or join our standards channel at ehealthforum.nz.

Background

This document provides a summarized description of the content changes included in the October 2023 production release of the SNOMED NZ Extension package.

It also includes technical notes detailing any known issues.

This SNOMED NZ Extension package is dependent upon and should therefore be consumed in conjunction with the SNOMED CT International Edition July 2023 release.

Content development activity

Summary

Content from the SNOMED CT International Edition July 2023 release has been incremented, using additional components for use in New Zealand. 

The October 2023 release includes updates to the previously released content in the SNOMED NZ Extension and introduces some new content.

This release includes new content in the following areas.

Assistance and preferences 

The assistance and preferences reference set identifies the types of assistance requirements or preferences a person may have in order to access health services.

Common patient friendly terms 

This reference set covers the most common health conditions and interventions, each with equivalent New Zealand English and te reo Māori consumer and whānau friendly terms.

Female pelvic surgical mesh injury

This reference set provides clinicians with a standard set of diagnosis codes to capture injuries and complications due to the implantation of surgical mesh to treat female stress urinary incontinence and pelvic organ prolapse. The set is developed and maintained by the New Zealand Female Pelvic Mesh Service.

Oral health

This reference set identifies coded terms to be captured in an oral health information system to support community oral health services, Māori oral health services and hospital dental services.

Rheumatic fever

This reference set relates to the diagnosis and management of rheumatic fever related conditions, including acute rheumatic fever and rheumatic heart disease. The reference set underpins standardised care plans and case management records, enabling nationally-consistent management of cases, reducing the risk of severe rheumatic heart disease and improving health outcomes.

CanShare

Te Aho o Te Kahu (Cancer Control Agency) has produced a collection of 298 CanShare reference sets for Aotearoa. These reference sets provide standard sets of SNOMED CT concepts to use for recording, sharing and querying cancer data . They are designed to support a range of cancer data, including histology, topography, grading, staging, scoring, treatment intents, disease response and cancer streams.

The October 2023 NZ SNOMED CT edition includes 226 new CanShare reference sets and 15 updated reference sets in the following areas:

• Cancer histologies for haematolymphoid, breast, thoracic, female genital, digestive and genitourinary tumours, based on the WHO Classification of Tumours 5th edition.

• Topographies for recording the body location of a cancer. This includes a maximal set of body locations, a high-level set of commonly used body locations, and body locations for specific thoracic and breast cancers.

• Grading systems and their values for haematolymphoid and breast cancers.

• Staging systems and their values for haematolymphoid, breast and thoracic cancers

• Prognostic scoring systems and their values for haematolymphoid cancers.

• Cancer groupings to support clinical workflows.

• Data that supports systemic anti-cancer therapy treatment plans, including basis of diagnosis, treatment intent, disease response, dose forms, dose units, and ancillary studies for breast tumours.

New and updated content

Concept statistics

The SNOMED NZ National Release Centre promoted 6 new concepts to the SNOMED CT International Edition January 2023 release.

Table 1. New concepts in the SNOMED International January 2023 release by hierarchy

There are 951 new concepts in our October 2023 release.

Table 2. New concepts in the SNOMED NZ Extension October 2023 release by hierarchy

Description statistics 

The SNOMED NZ NRC promoted 1 new descriptions to the SNOMED International Edition January 2023 release.

There are 3777 new descriptions in our October 2023 release.

For a statistical breakdown of the content of the SNOMED NZ Extension and the October 2023 release please visit release statistics site.

Reference sets

There are 369 reference sets in the October 2023 release including 231 new reference sets. The new reference sets cover assistance and preference, common patient friendy terms, female pelvic surgical mesh, rheumatic fever, oral health and CanShare reference sets.

For more information about New Zealand reference sets, please visit our website.

The New Zealand reference set list is available in Appendix 1, table 1.1.

Language reference sets

Language reference sets are created to define preferred terms and synonyms associated with each concept. There are three language reference sets in the October 2023 release.

Maps

Five maps between SNOMED CT and other code systems are contained in the October 2023 release.

Technical notes

Known issues 

Known issues are content or technical issues where the root cause is understood and the resolution has been discussed and agreed but has yet to be implemented. This can be due to a number of reasons, from lack of capacity within the current editing cycle, to the risk of impact to the stability of SNOMED CT if the fix were to be deployed at that stage in the product lifecycle.  

The following known issues were identified, and agreed to be resolved in the next editing cycle:

Notice of changes to the International Edition release schedule

The SNOMED CT International Edition has moved to a monthly release cycle. These more frequent releases of SNOMED CT will realize several benefits, including:

• The potential to be able to get content changes into the terminology in a shorter time frame.

• The fostering of better interoperability, as a result of entities being able to consume release content that is more aligned with other organizations.

• The prevention of circular dependencies that occur in longer projects, due to the move towards smaller, more manageable authoring projects.

• More automated validation services, as a result of the inherent removal of the Alpha/Beta stages in the Release cycle.

Whilst most users will continue unaffected (as they can simply continue to download the releases every 6 months as always), this transition will necessarily involve a few changes to process/packages:

• Delta files have been removed from releases of the SNOMED CT International Edition and SNOMED NZ Extension. A Delta Generation service will be provided for those who need it. The Delta Generation Tool allows users to create their own Delta between two fixed release dates - you can find it here:

  • https://github.com/IHTSDO/delta-generator-tool/releases

• The ICD-O/ICD-10 Maps will continue to be published in each Monthly International Edition release package (in line with that month's content) for the foreseeable future, unless we experience issues with the new process in Production, and they need to be removed at a later date.

The first monthly Release of the SNOMED CT International Edition was published on the 28th February 2022 with the Delta files having been removed, and therefore they will be removed from the New Zealand Extension from the April 2022 Release onwards.

Please note - While the SNOMED CT International Edition is moving to monthly releases, the New Zealand Extension of SNOMED CT will remain on the current bi-annual release schedule of April and October for 2023.

Changes to the Identifier file format

In line with the proposals documented here:  https://confluence.ihtsdotools.org/mag/snomed-international-proposal-to-change-the-rf2-identifier-file-specification - the New Zealand Extension Release will from now on include the following changes to the format of the Identifier files:

• < identifierSchemeId    alternateIdentifier    effectiveTime    active    moduleId    referencedComponentId           ...to

• > alternateIdentifier    effectiveTime    active    moduleId    identifierSchemeId    referencedComponentId

These improvements are introduced in the October 2023 New Zealand Extension release, and will be used in all future New Zealand Extension releases until further notice.

Appendix 1

Table 1.1 Reference sets in the SNOMED NZ Extension October 2023 release