Introduction

The International Classification of Nursing Practice (ICNP) Reference Set is a product agreed as part of a collaboration agreement between the International Council of Nurses (ICN) and the International Health Terminology Standards Organisation (IHTSDO), trading as SNOMED International. ICNP content has been incorporated into SNOMED CT and is being released as a reference set by SNOMED International on behalf of ICN. This production release is based on ICNP 2019 plus additional content requested by ICN.

Background

ICN and SNOMED International have worked together since 2006 to advance terminology harmonisation and foster interoperability in health information systems. This work resulted in the release of an equivalence table between the International Classification for Nursing Practice (ICNP®) and SNOMED Clinical Terms (SNOMED CT®) for nursing diagnoses and an equivalence table between ICNP and SNOMED CT for nursing interventions which were released 6 monthly until 2018. It also resulted in the SNOMED CT Nursing Activities Reference Set and SNOMED CT Nursing Health Issues Reference Set which were released until October 2021. No further releases of these reference sets are planned. 

ICN initiated a review of its role in health informatics globally, enabling them to develop a strategy for supporting nursing globally. It is this review which lead to the new agreement between ICN and SNOMED International, with the following key components:

• ICNP 2019 incorporated into SNOMED CT
• SNOMED International to maintain and distribute ICNP as a SNOMED reference set on behalf of ICN
• ICN to retain ownership of ICNP – SNOMED International to retain ownership of SNOMED CT
• ICN to continue to lead on ICNP clinical development over time and its quality assurance through ICN governance processes
• Free for use in SNOMED International member countries and licensed by ICN in non-member countries

ICN has established the ICNP Editorial Board through which decisions on the content of ICNP are made. The ICNP Editorial Board has put in place a mechanism for requesting changes and additions to ICNP reference set - for more information please contact icnp@icn.ch.

Motivation

The key drivers for this approach are:

• To ensure that nursing remains connected to the wider health information landscape globally
• To ensure that SNOMED CT continues to adequately reflect global nursing practice
• To ensure that information collected using ICNP can link to SNOMED CT encoded records and be shared with other healthcare professionals to support the care of individuals
• To capture nursing care in a standardised way thus avoiding local mapping which will lead to inconsistency
• To facilitate the sharing of ICNP-based information in a standardised way to support delivery of patient care, usage for research purposes and participation in health policy making

The ICNP, and therefore this reference set, is a terminology that enables nurses to describe and report their practice in a systematic way. The resulting information is used to support care and effective decision-making, and to inform nursing education and health policy. 

As ICNP is intended for use by and for nurses, ICN has been able to focus attention on the development of ICNP specifically for nursing practice. This has resulted in a rich and comprehensive resource that nurses can use to describe and report in detail the things that they assess (diagnoses e.g. nausea) and the things that they do (interventions e.g. counselling). The potential benefits of a consistent approach to capturing nursing data are far-reaching. However, nurses do not practice in isolation, they practice alongside many other disciplines. One of the potential risks of a specific nursing-focus is that nursing will be somehow disconnected from a larger health information landscape, hence the integration of ICNP into SNOMED CT. 

Design

The decisions about additions and changes to SNOMED CT as a result of the incorporation of ICNP 2019 and additional content into SNOMED CT has been directed by the advice given by subject matter experts from both organisations and also members of ICNP Editorial Board at ICN. To ensure fit with international requirements and other sources of terminology, the SNOMED International Nursing Clinical Reference Group has also provided advise and expertise.

This work provided an opportunity for ICN to review and make decisions about the content of ICNP 2019 and additional content. 

Versions

The version of ICNP used in this reference set is the May 2019 release plus additional content requested by ICN.  

The version of SNOMED CT used is the January 2025 International Release.

Content

The 2025 International Classification of Nursing Practice (ICNP) Reference Set is comprised of 2118 active concepts from the SNOMED CT Clinical Finding, Procedure and Situation with Explicit Context hierarchies. Changes to the membership of the reference set for the 2025 release includes replacements for inactivated concepts as well as the addition of new concepts. The table below details the changes. 

Obtaining the reference set

This reference set covers content of ICNP 2019 and additional content requested by ICN and is published as a Production release in March 2025. It should be noted that SNOMED International is not providing an equivalence table as part of the 2025 release. For further information regarding a human readable version of the current equivalence table please contact icnp@icn.ch

Access within SNOMED international member countries is provided by the Member National Release Centre in each country, via the relevant Member page. Users of ICNP in non-member countries need to gain a licence from ICN in the first instance, unless they are also SNOMED CT Affiliates in which case they will be able to access the files using their MLDS accounts. Please contact info@snomed.org and icnp@icn.ch for more information if required. 

Feedback

Feedback should be sent jointly to info@snomed.org and icnp@icn.ch. Feedback should include any issues relating to implementation, suggestions for future content inclusion or general comments regarding the subset.

Technical Notes

RF2 package format

The RF2 package convention dictates that it contains all relevant files, regardless of whether or not there is content to be included in each particular release.  Therefore, the package contains a mixture of files which contain both header rows and content data, and also files that are intentionally left blank (including only a header record).  The reason that these files are not removed from the package is to draw a clear distinction between:

1. ...files that have been deprecated (and therefore removed from the package completely), due to the content no longer being relevant to RF2 in this or future releases, and 
2. ...files that just happen to contain no data in this particular release (and are therefore included in the package but left blank, with only a header record), but are still relevant to RF2, and could therefore potentially contain data in future releases.

This allows users to easily distinguish between files that have purposefully been removed or not, as otherwise if files in option 2 above were left out of the package it could be interpreted as an error, rather than an intentional lack of content in that release.

Metadata now incorporated into the Derivative Packages

After consultation in 2023, SNOMED International have migrated the Metadata components for Derivative products from the International Edition to the Derivative release packages themselves.

These Derivatives are solely single refsets/maps, and so don’t mean anything to end users without the supporting terms and other components from the International content.  The nature of these products is therefore such that we necessarily create Derivative packages that are inherently dependent on the relevant International Edition content.  Previously, therefore, we have always created the metadata components (refset/module concepts, descriptions, relationships, etc) in the International Edition release packages, with the Derivative products being dependent on the relevant International content. 

Whilst this dependency on the International content continues, the metadata components are now included in the Derivative packages themselves, rather than in the International Edition packages

The consensus within the community is that moving the Metadata components into the Derivative packages will bring benefits to both the Derivative maintainers, and also to the end users who will no longer need to pull this particular data down from the dependent International Edition in order to use the Derivative products.   It enables maintainers to move to a more efficient model of hosting the Derivative content in termServer branches, rather than importing Delta files from external tools.

Therefore in the ICNP Refset releases from 2024 onwards, we have included the relevant metadata components in the following files in the Derivative release package:

• sct2_Concept_ICNPSnapshot_INT_20240101.txt
• sct2_Description_ICNPSnapshot-en_INT_20240101.txt

• der2_cRefset_ICNPLanguageSnapshot-en_INT_20240101.txt
• sct2_Relationship_ICNPSnapshot_INT_20240101.txt
• sct2_sRefset_OWLExpressionICNPSnapshot_INT_20240101.txt

Notice of changes to the ICNP Release package

In line with the refined implementation of Annotations, we are updating all products in order to align them with the updated version of the refsets in the International Edition Release package (which were first published in June 2024).

The languageCode field was specified as the two characters of ISO-639-1 code for the language of the annotation text. The change includes support for specifying dialect when it is applicable by adhering to RFC 5646, which allows the combination of two characters of ISO 639-1 code and two uppercase letters of country code (ISO 3166) separated by a hyphen.  The changes apply to both the Member Annotations String Value Reference Set + Component Annotation String Value reference set:

• The column "languageCode" has therefore been changed to "languageDialectCode".
  • Component Annotations (1292992004)
    • OLD:    id    effectiveTime    active    moduleId    refsetId    referencedComponentId    languageCode    typeId    value
    • NEW:   id    effectiveTime    active    moduleId    refsetId    referencedComponentId    languageDialectCode    typeId    value
  • Member Annotations (1292995002)
    • OLD:   id    effectiveTime    active    moduleId    refsetId    referencedComponentId    referencedMemberId    languageCode    typeId    value
    • NEW:  id    effectiveTime    active    moduleId    refsetId    referencedComponentId    referencedMemberId    languageDialectCode    typeId    value