1 Introduction

The Nutrition Care Process Terminology (NCPT) Nutrition Reference Set is a product agreed as part of a collaboration agreement between the Academy of Nutrition and Dietetics (the Academy) and the International Health Terminology Standards Organisation (IHTSDO), trading as SNOMED International. NCPT content has been incorporated into SNOMED CT and is being released as a reference set by SNOMED International on behalf of the Academy. This production release is based on NCPT 2020, which is available at www.nutritioncareprocess.org.

2 Background

An initial group of countries approached SNOMED International to include the Nutrition Care Process Terminology (NCPT) in SNOMED CT. Realising the importance of having a global nutrition language, in 2018 a formal relationship was established between SNOMED and the Academy to advance terminology harmonisation and foster interoperability in health information systems. This work is resulting in the release of this reference set that contains NCPT nutrition problems from the Clinical Finding and Situation with Explicit Context hierarchies. A future release of the reference set will contain the complete content of nutrition concepts in the NCPT. 

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

• NCPT 2020 incorporated into SNOMED CT
• SNOMED International to maintain and distribute NCPT Reference Set as a SNOMED reference set
• The Academy to retain ownership of NCPT – SNOMED International to retain ownership of SNOMED CT
• The Academy to continue to lead on NCPT clinical development over time and its quality assurance through Academy terminology processes
• Free for use in SNOMED International member countries

The Academy has established the Nutrition Care Process and Terminology Committee through which decisions on the content of NCPT are made and authoring guidelines are maintained. The Nutrition Care Process and Terminology Committee has put in place a mechanism for requesting changes and additions to NCPT reference set - for more information please contact ncp@eatright.org.

3 Motivation

The key drivers for this approach are:

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

The NCPT, and therefore this reference set, is a terminology that enables dietitians to describe and report their nutrition practice in a systematic way using the NCP. The resulting outcome is high quality nutrition care using a standardised quality improvement process to support care and effective decision-making, and to inform nutrition education and health policy. 

NCPT is intended for use by and for dietitians. The Academy has been able to focus attention on the development of NCPT specifically for the nutrition care process. This has resulted in a rich and comprehensive resource that dietitians can use to systematically provide tailored patient care and describe and report in detail the things that they assess (diagnoses e.g. inadequate intake of iron) and the things that they do (interventions e.g. counselling). The potential benefits of a consistent approach to capturing nutrition data using the NCPT are far-reaching. Broad adoption and use of the NCP and NCPT worldwide is supported by extensive resources (www.nutritioncareprocess.org). However, dietitians do not practice in isolation, they practice alongside many other disciplines. One of the potential risks of a specific nutrition-focus is that nutrition will be somehow disconnected from a larger health information landscape, hence the integration of NCPT into SNOMED CT. 

4 Future releases

The SNOMED NCPT reference set was initially released April 2024 as planned and contained NCPT nutrition problems from the Clinical Finding and Situation with Explicit Context hierarchies.  It has been agreed with the Academy that the April 2025 release of the SNOMED NCPT reference set will contain NCPT nutrition problems from the Clinical Finding and Situation with Explicit Context hierarchies and NCPT nutrition interventions primarily from the Procedure hierarchy (i.e. nutrition diagnosis findings, nutrition intervention procedures). The next release, April 2026, will contain the complete NCPT, pending available resources, including nutrition assessment concepts from SNOMED CT’s observation and finding hierarchies and then be maintained annually in April. This supports changes to the release cycles of derivatives at SNOMED International and will also allow the Academy a further period to collect and agree additions to NCPT which are being proposed by users through the Nutrition Care Process and Terminology Committee. This annual update cycle by the Academy ensures that the NCPT refset remains current and in line with global nutrition practice.

It should be noted that the content of the NCPT Refset (April 2025) will be included in the free for use Global Patient Set which will be issued later in 2025 by SNOMED International.

5 Design

The decisions about additions and changes to SNOMED CT as a result of the incorporation of NCPT 2020 into SNOMED CT has been directed by the advice given by subject matter experts from both organisations and also members of Nutrition Care Process and Terminology Committee and its subcommittees at the Academy. To ensure fit with international requirements and other sources of terminology, the SNOMED International Nutrition and Dietetics Clinical Reference Group has also provided advise and expertise.

This work provided an opportunity for the Academy to review and make decisions about the content of NCPT 2020. 

6 Versions

The version of NCPT used in this reference set is the 2020 NCPT release. Mapping between NCPT and SNOMED CT is available for organizational subscribers at nutritioncareprocess.org. 

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

7 Effective Date

The Refset is aligned to the January 2025 SNOMED CT International Release.  The effectiveTime for the content has therefore been set to 20250101 (1st January 2025). 

8 Feedback

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

Additionally, as part of on-going evaluation and assessment of the Collaborations Portfolio, the SNOMED International Collaboration team welcomes feedback, use case examples and showcase of benefits of this refset. Please send information to Suzy Roy (sro@snomed.org). 

9 Technical Notes

9.1 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.

9.2 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 NCPT Refset releases from 2024 onwards, we have included additional metadata components that used to reside solely in the International Edition.  These will include the NCPT module concept + description records, etc.

If you have any feedback on the metadata components, please contact SNOMED International on release@snomed.org

Notice of changes to the NCPT 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