Introduction

Health New Zealand | Te Whatu Ora 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 a standard FHIR® API using the NZ Health Terminology Service. 

We welcome your feedback and participation. For more information about SNOMED CT implementation in New Zealand, email standards@tewhatuora.govt.nz, visit our website or join the standards channel at ehealthforum.nz.

Background

This document summarises the content changes included in the April 2025 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 CTInternational Edition February 2025 release.

New and updated content

The April 2025 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.

Gambling harm intervention reference set

This reference set has been developed to support the collection and reporting of gambling harm intervention data as specified by draft standard HISO 10112:2025 Gambling Harm Intervention Data Standard.

Health service type reference set

This reference set has been updated in partnership with Healthpoint to extend the SNOMED CT content available for the health directory services used by consumers, health professionals and helplines.

Patient friendly terms

The set of patient friendly terms in NZ English and Te Reo Māori for health service types has been further extended in partnership with Healthpoint and Te Taura Whiri i te Reo Māori | Māori Language Commission.

Emergency care reference sets

The chief presenting complaint and diagnosis reference sets have been updated as a result of the latest six-monthly review in February 2025.

CanShare reference sets

Te Aho o Te Kahu | Cancer Control Agency has developed a collection of CanShare reference sets for New Zealand and this content has been further extended in this release. These reference sets provide standard sets of SNOMED CT concepts to use for recording, sharing and querying cancer data in Aotearoa. Each concept in these reference sets has a preferred term in the CanShare language reference set (SCTID 231621000210105), selected by New Zealand clinicians to standardise the way that cancer data is displayed . These reference sets support a range of cancer data, including key diagnostic components, treatment plans, national registers and screening programmes.

The April 2025 release includes 53 new CanShare reference sets, 115 updated reference sets, 459 static reference sets and 443 new concepts in the following areas:

• Cancer streams, sub-streams and primary cancer types to support clinical workflows for medical oncology and haematology.
• Topographies for recording the primary site of a cancer. This includes a maximal set of body sites, a high-level set of commonly used body sites, and body sites specific to breast, thoracic, gastrointestinal, female genital, genitourinary, soft tissue & bone, skin, head & neck, central nervous system, endocrine & neuroendocrine, and eye cancers.
• Lymph nodes for recording a lymph node site (for pathology or surgery) for breast, thoracic, gastrointestinal, female genital, genitourinary, head & neck, and eye cancers.
• Cancer histologies for haematologic, breast, thoracic, gastrointestinal, female genital, genitourinary, soft tissue & bone, skin, head & neck, central nervous system, endocrine & neuroendocrine, eye, and paediatric (new) cancers, based on the WHO Classification of Tumours 5th edition.
• Grading systems for haematology and solid (new) cancers.
• Staging systems (AJCC and non AJCC) for haematology and solid (new) cancers, including clinical, pathological, and a subset of recurrence or retreatment, and post therapy or post neoadjuvant therapy staging.
• Prognostic scoring systems for haematology, female genital, and genitourinary (new) cancers.
• Neoadjuvant therapy response scoring systems for breast, colorectal, and female genital cancers.
• Specimen collection procedures and specimens to support all cancer types.
• Ancillary study tests and results for a wide range of cancers, to support testing eligibility for new cancer medicines (new), as well as breast and colorectal (new) cancers.
• Additional data to support radiation oncology and systemic anti-cancer therapy treatment plans, radiation oncology waitlist data (new) and national screening programmes eg, national cervical screening programme (new).

Systemic anti-cancer therapy regimens

Further concepts representing systemic anti-cancer therapy regimens have been added to support the CanShare programme.

Other changes

Fifteen reference sets have been updated to replace inactive concepts with the active concepts.

Release statistics

Concept statistics

Requests from the SNOMED NZ National Release Centre to SNOMED International have resulted in the promotion of one new concept into the International Edition between October 2024 and February 2025.

Table 1. New concepts in the SNOMED International Edition February 2025 release by hierarchy

There are 549 new concepts added to SNOMED NZ Extension April 2025 release.

Table 2. New concepts in the SNOMED NZ Extension April 2025 release by hierarchy

Description statistics 

There are 2121 new descriptions added to our April 2025 release.

For a statistical breakdown of the content of the SNOMED NZ Extension and the April 2025 release please visit release statistics site.

Reference sets

There are 731 reference sets in the April 2025 release including 54 new reference sets. 

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

You can access New Zealand reference sets without log-in by visiting SNOMED CT Reference set Tool 2.0. Once there click on library in the top right-hand corner and then you can filter on New Zealand NRC in the organisation column and select the preferred reference set. 

Please note due to licencing reasons only a simplified RF2 version or a list of ID's can be downloaded for unregistered users.

Deprecated and inactivated reference sets

88 reference sets have been removed from the April 2025 release, and 31 reference sets have been inactivated pending full deprecation in the October 2025 release.

Table 3.1 Deprecated reference sets (These reference sets have been removed from the April 2025 release)

Table 3.2 Inactivated reference sets (These reference sets have been inactivated and will be removed in the October 2025 release)

Language reference sets

Language reference sets are created to define preferred terms and synonyms associated with each concept. There are four language reference sets in the April 2025 release.

Maps

Five maps between SNOMED CT and other code systems are contained in the April 2025 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.

Notice of changes to the NZ Extension Release package

The New Zealand NRC has decided to extend the standard International DescriptionType specification, which currently restricts Description term lengths to 255 characters. The New Zealand Extension from April 2024 onwards, now specifies term lengths can be created up to 4096 characters.

This means that users wanting to utilise New Zealand Extension Descriptions, should use the specialised New Zealand DescriptionType.