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 forum.hinz.org.nz.

Background

This document provides a summarized description of the content changes included in the April 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 January 2023 release.

Content development activity

Summary

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

The April 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.

Health consumer information

The New Zealand health consumer information reference set consists of common terms used on websites and in patient information leaflets to describe diseases, tests and treatments (other than medicines) in a form consumers and whānau can understand. This content has been developed in partnership with Health Navigator.

Family planning

The New Zealand Family Planning reference set identifies common symptoms, diagnoses and procedures that are referred to when seeing patients for their sexual and reproductive health. This content has been developed in partnership with New Zealand Family Planning.

Minor procedures

A collection of five reference sets has standard codes for recording minor procedures performed in outpatient clinics. Reporting the procedure performed for the five purchase units listed below will reduce the number of new purchase units required for specific procedures and will allow more accurate counting of some procedures – for example, when NNPAC data is linked to hospital costing data.

The five reference sets are:

• New Zealand purchase unit code S00008 minor operation reference set

• New Zealand purchase unit code S25006 ear, nose and throat minor operation reference set

• New Zealand purchase unit code S30008 gynaecology minor procedure reference set

• New Zealand purchase unit code S40008 eye procedure reference set

• New Zealand purchase unit code S60007 plastic surgery minor procedure reference set

CanShare

Te Aho o Te Kahu (Cancer Control Agency) has produced a collection of 72 reference sets for recording, sharing and querying cancer data on the CanShare platform. The collection includes Anti-Cancer Therapy - Nationally Organised Workstreams (ACT-NOW) reference sets, histology reference sets for haematolymphoid tumours (based on the WHO Classification of Tumours, 5th edition), TNM cancer staging reference sets for breast and haematologic malignancies (based on the AJCC cancer staging manual, 8th edition) and general reference sets used across a range of cancer data.

New and updated content

Concept statistics

The SNOMED NZ National Release Centre promoted 12 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 362 new concepts in our April 2023 release.

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

Description statistics 

The SNOMED NZ NRC promoted 4 new descriptions to the SNOMED International Edition January 2023 release.

There are 1253 new descriptions in our April 2023 release.

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

Reference sets

There are 138 reference sets in the April 2023 release including 79 new reference sets. The new reference sets cover family planning, health consumer information 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 April 2023 release.

Maps

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

Appendix 1

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