Introduction

The Alpha release of the SNOMED CT to Orphanet equivalency table Map is a the product of an ongoing programme of work a joint project carried out under a pre-existing collaboration agreement between INSERM and the International Health Terminology Standards Organisation (IHTSDO). The work commenced in May 2014 and the first joint release of the candidate baseline equivalency table took place in April 2015, for review and feedback.

2 Background

The overarching aim of the collaboration agreement, first established in 2010 and updated in September 2014, was to advance terminology harmonisation and foster interoperability in health information systems. Joint work would build on previous efforts, culminating in joint publication of: 

a) An equivalence table between Orphanet® and SNOMED Clinical Terms (SNOMED CT®) for rare diseases

The initial effort centred on nursing diagnoses, specifically problems – the focus of this release document. Other related work includes the identification of SNOMED CT equivalencies for Orphanet nursing interventions and in the future Orphanet positive nursing diagnoses (i.e. goals or expected outcomes).

3 Motivation

The Orphanet, a product of the INSERM, 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. 
SNOMED CT is the most comprehensive and precise clinical health terminology product in the world, owned and distributed around the world by The International Health Terminology Standards Development Organisation (IHTSDO). 
The equivalency table is intended for use by nurses, and other interested professional groups. Robust systems and processes within INSERM and IHTSDO assure the integrity of both terminologies. 

Institut national de la sante et de la recherche medicale (INSERM) and SNOMED International. Based on an agreed priority set, new concepts for rare diseases as defined in Orphanet have been added to SNOMED CT.  A map from SNOMED CT to Orphanet has been created.

This document is intended to provide a brief description, background context and explanatory notes on the SNOMED International/INSERM collaborative work and and the resulting SNOMED CT to Orphanet map.   The map is being published as an Alpha release at this time with the intention to publish a production release in April 2021.   This document is not intended to provide technical specifications about SNOMED CT or Orphanet.   Editorial guidance for SNOMED CT content can be found in the SNOMED CT Editorial Guide.   Editorial guidance for Orphanet Nomenclature of Rare Diseases can be found in Orphanet

 (https://www.orpha.net/consor/cgi-bin/Education_Procedure.php?lng=en) 

and Orphadata

 (http://www.orphadata.org/cgi-bin/ORPHAnomenclature.html)

This ALPHA release package is distributed for evaluation purposes only.  It must not be used in production clinical systems or in clinical settings, or distributed to Affiliate Licensees or any third parties.   .

Audience

The audience for this document includes National Release Centers, vendors of electronic health records, terminology developers, researchers, genomics experts and individuals who wish to have an understanding of the content of the SNOMED CT to Orphanet map.

Background

SNOMED International (then IHTSDO) and INSERM first started exploring opportunities for linking SNOMED CT and Orphanet Rare Disease in 2012 because of the drivers to link between clinical data using SNOMED CT and the mandated use of Orphanet for rare disease research purposes in Europe and other countries outside Europe. As a consequence, an agreement was signed in 2014 and a priority set of rare diseases was agreed. Since then, the two organisations have worked closely as follows to:

1. Undertake a gap analysis for the defined set.
2. Develop textual definitions for the rare diseases based on expert input through the INSERM community.
3. Create new content in SNOMED CT.
4. Create a map between existing and new content in SNOMED CT and Orphanet.
5. Ensure throughout the development period that new SNOMED CT content aligns with changes in Orphanet.

Approximately 3500 new rare disease concepts have been added to SNOMED CT as part of this collaboration and the resulting map product contains 5,721 SNOMED CT and Orphanet concepts/terms.

In parallel to the content development and mapping work, the operational aspects have been worked on to agree activities and processes to enable the Map to move in to Production in April 2021 and from there to be maintained and updated according to changes within the 2 terminologies. As a consequence, an updated Agreement was signed in March 2020 signalling both organisations commitment to maintaining and updating the content and map.

At this time, SNOMED International and INSERM are seeking feedback on the Alpha version of the Map. The review period will end on 31 November 2020, after which time work will be undertaken to update the content of the Map in line with the January 2021 SNOMED CT International Release and Orphanet July 2020 coding release. A report of the feedback will be made available. Please note that the Map will NOT be extended beyond its current scope for the Production release. The Production release will be April 2021.

Scope and Purpose of Collaborative Work

The scope of the SNOMED International and INSERM work has been outlined above, and the 2 organisations have formalised the next steps as part of a new Collaboration agreement which ensures that the Map is updated, after feedback from the Alpha release, to form the Production release in April 2021. 

Under the terms of the Collaboration agreement between SNOMED International and INSERM, the Map will be issued annually by both SNOMED International in RF2 format and INSERM in spreadsheet format. Documented quality assurance processes will ensure both formats are the same and supporting materials are produced jointly. In addition, criteria for extending the Map will be agreed and managed through agreed processes to ensure that the product meets the needs of the different stakeholder groups based on use cases.

Design

Map

Decisions about maps between pre-existing content in SNOMED CT and Orphanet, the creation of new content for SNOMED CT and also Orphanet, and the validation of the map between SNOMED CT and Orphanet were made by consensus between both organisations.

Version

The version of Orphanet used is January 2020

4 Design

Decisions concerning source concepts, target concepts and validity of equivalencies were made by consensus of all parties (INSERM, IHTSDO, etc). The SNOMED International Nursing Derivatives Editorial Group now provides international validation of the content included in the set prior to publication with each release.

4.1 Versions

The version of Orphanet used is the May 2017 release.  

The version of SNOMED CT used is the July 2018 January 2020 International Release.

Source for Map

The source data is a subset of 852 Orphanet concepts.

4.3 Target

All target concepts are drawn from SNOMED CT Clinical Findings and Situation. As part of the work, new concepts were identified as relevant and needed within SNOMED CT. These were modeled as Clinical Findings.

4.4 Direction

5721 SNOMED CT concepts.

Direction of Map

The direction of the map The direction is from SNOMED CT January 2020 International Release to the Orphanet classification in line with the stated use case in section 3.

Cardinality of Map

The cardinality for all equivalencies in the table is one-to-one.

5 Content

The SNOMED CT to Orphanet equivalency table covers just one semantic type – nursing diagnoses (problems) – with equivalent Orphanet and SNOMED CT concepts for each problem. The table comprises 529 active equivalencies, representing a subset of Orphanet and a subset of SNOMED CT – equivalencies have not been identified for all Orphanet diagnoses, or for all SNOMED CT Clinical Findings. 

5.1 Changes for the July 2018 release

As a result of changes made to the July 2018 release of SNOMED CT, there were 0 Orphanet codes for diagnoses which were removed from the table.

The following members have been removed from the equivalency table:

inactive_concept_name

assoc_type_name

New target

New target_name

 INSERM Comments

, one SNOMED CT concept maps to one Orphanet entry.

Obtaining the Alpha release

Access within SNOMED International

None required in this editing cycle

6 Obtaining the equivalency table

The equivalency table was released in April 2015 as a technology preview/candidate baseline and has subsequently been maintained according to the release schedules of Orphanet and SNOMED CT. The baseline release of the equivalency table was released after July 2015, following agreement between INSERM and IHTSDO. 

Access within IHTSDO member countries is provided by the Member National Release Centre in each country, via the relevant Member page. Affiliates of IHTSDO SNOMED International in non-member countries can access the table map file through their Member Licensing and Distribution Service (MLDS) account. Please contact info@snomed.org for more information if required. 

The equivalency table Map in spreadsheet form is available for download from the Orphanet website: 
xxxxxxxxxxxxwww.orphadata.org

If you’re having any problems getting hold of the Orphanet Map Package, please contact info@snomed.org.

Users of the table should map must comply with licensing arrangements for both Orphanet and SNOMED CT and Orphanet.

Feedback

Feedback should be sent jointly to info@snomed.org and aamherdt@uwmcontact.orphanet@inserm.edufr.

Feedback should include any issues relating to implementation, suggestions for future content inclusion or general comments regarding the subsetmap.

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.