Introduction
SNOMED CT terminology provides a common language that enables a consistent way of indexing, storing, retrieving, and aggregating clinical data across specialties and sites of care. The SNOMED CT NL Edition is a combination of the full July 2023 SNOMED CT International Edition and the NL Extension of SNOMED CT.
The International Health Terminology Standards Development Organisation (IHTSDO®), trading as SNOMED International, maintains the SNOMED CT technical design, the content architecture, the SNOMED CT content (includes the concepts table, the descriptions table, the relationships table, a history table, and ICD mappings), and related technical documentation. The SNOMED CT NL Edition is developed and maintained by the NL NRC and is available to authorized Licensees. This material includes SNOMED CT which is used by permission of the IHTSDO. All rights reserved.
SNOMED CT was originally created by the College of American Pathologists. "SNOMED" and "SNOMED CT" are registered trademarks of IHTSDO.
Background
This document provides a summarized description of the content changes included in the March 2024 release of the SNOMED Clinical Terms® NL Edition.
It also includes technical notes detailing the known issues which have been identified. These are content or technical issues where the root cause is understood, and the fix has been discussed and agreed, but has yet to be implemented.
This document is available as a web resource as well as alongside the March 2024 NL Edition release.
Scope
This document is written for the purpose described above and is not intended to provide details of the technical specifications for SNOMED CT or encompass every change made during the release. These Release Notes should be used in combination with the SNOMED CT February 2024 International Edition - SNOMED International Release notes.
Changes to the release format
Preceding the September 2022 release, our SNOMED NRC changed to a new authoring platform. This necessitated a number of changes in our release. For details, please refer to sections 3.3 & 3.4 of the SNOMED CT Managed Service - Netherlands Edition Release Notes - September 2022. However, we failed at that time to describe the consequences for the National Terminology Server with respect to patient-friendly terms. Retrieving the patient-friendly term now requires a different query. For details, please read the following section on the National Terminology Server.
Preparation for monthly releases of the NL edition
As you may already know SNOMED International have transitioned to a monthly delivery schedule for the International Edition of SNOMED CT. The move towards more frequent releases of SNOMED CT realizes 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.
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 have been removed from the NL Edition from the September 2022 Release onwards.
Nictiz has received several requests to publish more frequently as well. We plan to publish monthly from October 2024 onwards – weather and tooling permitting. We will use the intervening seven months to:
- Streamline our internal processes to enable monthly releases.
- Gather a group of SNOMED stakeholders to discuss the consequences of monthly releases and agree on how to handle them.
- Formulate a release policy in accordance with Nictiz’ Duurzaam releasebeleid.
- Publish a guide on how and when to update SNOMED; and on how to deal with issues that arise from organisations using different versions.
We are looking for you as a stakeholder to give us insight into your needs and into the impact of this change on your business process. If you are willing to participate, please submit a request at the Nictiz Servicedesk with the subject Monthly SNOMED releases – stakeholder participation.
Patient-friendly terms and explanations
In 2023-2024 Nictiz and MedMij have run a pilot project Patiëntvriendelijke Termen, the aim of which was to establish a set of requirements for patient-friendly terms and explanations of SNOMED concepts, a process for their development and a tried and tested method of distribution. This has led to a small number of new explanations which are published in the March 2024 release. More importantly, it has caused us to evaluate the release format for patient-friendly terms and explanations. We believe that a number of changes are necessary:
- We currently have two language reference sets for patient-friendly terms: one on B1 reading level and another which does not specify reading level. One of the project outcomes is that all explanations should have a reading level of B1 at most. As in future all explanations will be at B1 reading level, there is no reason to keep the distinction in reference sets. Thus:
- 160161000146108 | Patient-friendly Dutch at B1 reading level language reference set| will be retired starting September 2024.
- Any patient-friendly terms in the Patient-friendly Dutch at B1 reading level language reference set| that are not at B1 reading level will be retired.
- At present, patient-friendly explanations are added to SNOMED concepts as text definitions in a patient-friendly language reference set. This is misleading, as the explanations are in no way definitions: they are not unique to the concept and do not fully represent it. It also causes difficulties in maintenance. Therefore:
- All text definitions in both patient-friendly language reference sets will be retired.
- We will publish a separate file through MLDS that contains explanations with a UUID to identify them.
- To SNOMED concepts we will add an Annotation of type Consumer explanation whose value is the UUID of an explanation.
The National Terminology Server provides an easy method of accessing the latest SNOMED edition in the FHIR R4 format. Using this server is free of charge. More information, including a manual, can be found at https://www.nictiz.nl/standaardisatie/terminologiecentrum/nationale-terminologieserver/ and https://github.com/terminologieserver.
Content Development Activity
Summary
The March 2024 SNOMED CT NL Edition contains content authoring tooling and release production provided by SNOMED International Managed Service. Quality assurance of the release was completed by both the NL NRC and SNOMED International.
March 2024 NL Edition of SNOMED CT Statistics
These statistics include the content from the February 2024 International Edition and March 2024 NL Edition.
Release | Active Concept Count | Active NL Description Count | Active Relationship Count |
---|---|---|---|
NL Edition of SNOMED CT (includes February 2024 International Edition) | 379,548 | 938,983 | 1,334,653 |
NL Extension of SNOMED CT | 13,545 | 938,983 | 84,663 |
These statistics include new content from the March 2024 NL Extension.
Statistics for March 2024 NL Edition of SNOMED CT | |
#total | |
---|---|
Number of new active NL concepts | 147 |
Number of new active descriptions | 12,806 |
Number of new active relationships | 5,264 |
Number of newly inactivated concepts | 89 |
Total number of translated active concepts | 280,618 |
SNOMED CT derived products
New reference sets
Dutch mental health diagnoses simple reference set | Handpicked set of diagnoses that are relevant in mental health care. | 350401000146101 |
Changed reference sets
Dutch food allergen simple reference set | Handpicked set of food allergens. | 98011000146102 |
Dutch total non-drug allergen simple reference set | Intensional reference set which contains all allergens from our 5 handpicked allergen simple reference sets. | 98061000146100 |
Dutch implant registry simple reference set | Combination of handpicked set and intensional set of implants that need to be delivered to the national implant registry by the hospitals. | 52801000146101 |
Dutch implants reference set - intensional | Intensional set of implants that need to be delivered to the national implant registry by the hospitals. | 117721000146102 |
Dutch non-drug allergen simple reference set for Dutch clinical building blocks version 2017 | This temporary reference set has been reactivated especially for the Dutch clinical building blocks version 2017. This reference set contains exactly the same content as 98061000146100 |Dutch total non-drug allergen simple reference set| in order to be able to use the correct content without changing the Dutch clinical building blocks 2017 release. This reference set is valid until the Dutch clinical building blocks 2017 may no longer be used. If at all possible, please use the Dutch total non-drug allergen simple reference set instead (row above). | 42931000146101 |
Dutch microorganism simple reference set | >4,000 micro-organism concepts for registration in Dutch laboratories. | 2581000146104 |
Dutch pathology simple reference set | Handpicked set of concepts for the Dutch PALGA thesaurus | 110851000146103 |
Dutch nursing observations for suicide simple reference set | Handpicked set of suicide observations. | 140971000146107 |
Dutch nursing observation simple reference set | Intensional reference set which contains all observations from the 5 nursing observation simple reference sets. | 140991000146106 |
Dutch nursing problem simple reference set | Dutch nursing problems which have been translated to Dutch and also possess Dutch textual definitions. | 11721000146100 |
Dutch nursing problems with sections of e-transfer simple reference set | Dutch nursing problems extended with sections of e-transfer, to be able to sort the nursing problems according to the e-transfer sections | 117701000146105 |
Dutch optometric diagnoses simple reference set | Diagnoses relevant to optometry. | 41000146103 |
Dutch rare neuromuscular disorders simple reference set | Rare neuromuscular disorders: selection based on the CRAMP classification. | 2551000146109 |
SNOMED CT to Omaha correlated extended map reference set of patient problems | Maps the SNOMED CT concepts in the Dutch nursing problem reference set to OMAHA system codes | 32311000146108 |
SNOMED CT to ICF correlated extended map reference set of patient problems | Maps the SNOMED CT concepts of the Dutch nursing problem reference set to ICF codes. | 32321000146103 |
SNOMED CT allergens to drug excipient correlated map reference set | Maps SNOMED CT allergen concepts to G-standaard drug excipient codes. | 148521000146104 |
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 are Known Issues for the SNOMED CT NL Edition that have been identified and will be resolved in the next editing and production cycle:
Resolved Issues
Resolved issues are Known Issues which were not fixed as part of the previous release lifecycle, but which have now been resolved for this March 2024 NL Edition. These can be issues found during the Pre-Production or Production phases of the testing of the current release, which were resolved before the final deployment of the final production release. Finally these can be issues which were reported or found during the testing phase, but which have been closed without any action taken.
The following Resolved Issues for the SNOMED CT March 2024 NL Edition:
Technical Updates
Technical Updates reported in the following monthly Release Notes:
- https://confluence.ihtsdotools.org/display/RMT/SNOMED+CT+september+2023+International+Edition+-+SNOMED+International+Release+notes
- https://confluence.ihtsdotools.org/display/RMT/SNOMED+CT+october+2023+International+Edition+-+SNOMED+International+Release+notes
- https://confluence.ihtsdotools.org/display/RMT/SNOMED+CT+november+2023+International+Edition+-+SNOMED+International+Release+notes
- https://confluence.ihtsdotools.org/display/RMT/SNOMED+CT+december+2023+International+Edition+-+SNOMED+International+Release+notes
- https://confluence.ihtsdotools.org/display/RMT/SNOMED+CT+january+2024+International+Edition+-+SNOMED+International+Release+notes
- https://confluence.ihtsdotools.org/display/RMT/SNOMED+CT+february+2024+International+Edition+-+SNOMED+International+Release+notes
There are no technical updates that pertain to the NL Edition.
RF2 package format
Similar to the International Edition, the NL Edition follows the technical specifications for RF2 packaging format.
For future reference, 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.
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 Netherlands Edition 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 were introduced in the September 2023 Netherlands Edition release, and will be used in all future Netherlands Edition releases until further notice.
Notice of changes to the NL Extension Release package
In line with the new implementation of Annotations, two new refsets have been added to the International Edition Release package, from December 2023 onwards:
- der2_scsRefset_ComponentAnnotationStringValueSnapshot_INT_20231201.txt
- der2_sscsRefset_MemberAnnotationStringValueSnapshot_INT_20231201.txt
The latest version of the NL Extension release is based upon the February 2024 International Edition, and therefore these Annotations file types will also be included in the NL Extension release package from the March 2024 NL release onwards, until further notice:
- der2_scsRefset_ComponentAnnotationStringValueFull_NL1000146_20240331.txt
- der2_scsRefset_ComponentAnnotationStringValueSnapshot_NL1000146_20240331.txt
- der2_sscsRefset_MemberAnnotationStringValueFull_NL1000146_20240331.txt
- der2_sscsRefset_MemberAnnotationStringValueSnapshot_NL1000146_20240331.txt
- der2_scsRefset_ComponentAnnotationStringValueFull_NL1000146_20240331.txt
These refset files are empty for the March 2024 NL Extension release, whilst content is being authored for future editing cycles.
Feedback and suggestions
We welcome questions, comments or suggestions to improve the quality, accuracy and usability of the SNOMED CT NL Edition. Please submit a request at the Nictiz Servicedesk.
Approvals
Final Version | Date | Approver | Comments |
---|---|---|---|
1.0 | 25-3-2024 | Feikje Hielkema-Raadsveld | Approved |
Draft Amendment History
Version | Date | Editor | Comments |
---|---|---|---|
0.1 |
| Andrew Atkinson | Initial draft created |
0.2 | 19-3-2024 | Feikje Hielkema-Raadsveld | Revised draft |
1.0 | 25-3-2024 | Feikje Hielkema-Raadsveld | Final updates |