1. Introduction

SNOMED International has introduced the Global Patient Set (GPS) to support the sharing of patient health information coded with SNOMED CT without the need for a SNOMED International license. 

The GPS is a managed list of existing SNOMED CT unique concept identifiers and their associated descriptions and will be available to all interested parties at no cost to users. The GPS supports health information interoperability across care settings, systems, organizations and national borders.  

2. Implementation

The SNOMED International GPS Implementation Guide provides information on downloading the GPS and considerations for its use.  A PDF version of the SNOMED International GPS Implementation Guide is included in the GPS release package - however to ensure that the latest version can be accessed, it's also available online:

https://confluence.ihtsdotools.org/display/RMT/SNOMED+International+Global+Patient+Set+%28GPS%29+package+Implementation+Guide+-+September+2021

3. Release content

3.1.1. Frequency of Release

The GPS package contains the content of a number of SNOMED CT reference sets to support a variety of general purposes.  It will be published annually.

3.1.2. Changes to the GPS Release content

Changes to the content of the GPS release package each cycle will reflect updates to the underlying terminology, including concept inactivations and additions.  For this reason, details of changes made to this release can be found in the Release Notes for the underlying SNOMED CT reference sets that are used to compile the GPS.

From the July 2020 GPS Release onwards, SNOMED International will also be publishing an RF2 formatted package containing the GPS refset content.  This Refset will follow normal RF2 conventions, and will therefore retain a full historical audit trail of all changes to the GPS refset from that point onwards.

3.1.2.1. Significant changes:  COVID-19

SNOMED CT concepts have been created and added to the GPS so that these codes are globally available to all implementers. Details on the SNOMED CT concepts included can be found here - http://snomed.org/covid-19

3.1.2.2. Significant changes:  Organism content relating to breeds

There were approximately 3000 concepts in the organism hierarchy that were related to various breeds.  Based on the editorial guidelines, breeds are restricted to the veterinary domain.  These concepts have therefore been inactivated from the International release and moved to the veterinary extension.  In order to align the GPS package with this, we have also inactivated them in the GPS RF2 Refset in this cycle.  The inactive content will not be included in the GPS Freeset deliverable, as this has no mechanism for retaining historical content.

4. Obtaining the GPS package

The GPS is downloadable from the following page on the SNOMED International website:

http://www.snomed.org/snomed-international/learn-more/global-patient-set

If you would like to obtain the full version of SNOMED CT through membership or an affiliate license, please visit

https://www.snomed.org/snomed-ct/get-snomed

5. Technical Notes

5.1.1.  RF2 package format

The GPS Freeset is released in TSV (Tab Separated Values) file format, with the following naming convention:

• SnomedINTL_GPSRelease_PRODUCTION_[date and time stamp].zip

The GPS RF2 Refset is released in RF2 file format, with the following naming convention:

• SnomedCT_GPS_PRODUCTION_[date and time stamp].zip

Please be aware that the RF2 refset contains records with the GPS specific moduleID (890195008) + refsetID (787778008) allocated to them all, regardless of the concepts origin in the various GPS feeder refsets.  This is because there are several thousand concepts that exist across multiple feeder refsets, and therefore it would prove confusing from a user-perspective to choose one module/refset combination over another without any reason.

5.1.2. Inactive Content

Due to the historical features of the RF2 format, we are able to include inactive content in the GPS Refset product.  This means that any concepts inactivated since the previous GPS release will be included in the GPS RF2 files, with a status of "active=0".   The inactive content will not be included in the GPS Freeset deliverable, as this has no mechanism for retaining historical content.

This inactive content should be used entirely at the users own risk, as these concepts have been inactivated for clinical or editorial validity reasons and are therefore considered as obsolete by SNOMED International.  They are therefore no longer maintained, and as such should not be used in Production clinical systems or in clinical settings.

5.1.3. New files added to the RF2 package format for Derivative products

In order to bring the package format in line with the latest SNOMED International packaging conventions, several new files have been added to the 2021 derivative product release packages:

• > sct2_RelationshipConcreteValues_GPSDelta_INT_20210731.txt
  > sct2_RelationshipConcreteValues_GPSFull_INT_20210731.txt
  > sct2_RelationshipConcreteValues_GPSSnapshot_INT_20210731.txt
• > sct2_sRefset_GPSOWLExpressionDelta_INT_20210731.txt
  > sct2_sRefset_GPSOWLExpressionFull_INT_20210731.txt
  > sct2_sRefset_GPSOWLExpressionSnapshot_INT_20210731.txt
• > der2_ssccRefset_GPSMRCMAttributeRangeDelta_INT_20210731.txt
  > der2_ssccRefset_GPSMRCMAttributeRangeFull_INT_20210731.txt
  > der2_ssccRefset_GPSMRCMAttributeRangeSnapshot_INT_20210731.txt
• > der2_sssssssRefset_GPSMRCMDomainDelta_INT_20210731.txt
  > der2_sssssssRefset_GPSMRCMDomainFull_INT_20210731.txt
  > der2_sssssssRefset_GPSMRCMDomainSnapshot_INT_20210731.txt
• > der2_cRefset_GPSMRCMModuleScopeDelta_INT_20210731.txt
  > der2_cRefset_GPSMRCMModuleScopeFull_INT_20210731.txt
  > der2_cRefset_GPSMRCMModuleScopeSnapshot_INT_20210731.txt
• > der2_cissccRefset_GPSMRCMAttributeDomainDelta_INT_20210731.txt
  > der2_cissccRefset_GPSMRCMAttributeDomainFull_INT_20210731.txt
  > der2_cissccRefset_GPSMRCMAttributeDomainSnapshot_INT_20210731.txt

These files will likely remain empty of content in this derivative product package, but are included to ensure consistency across the SNOMED International catalog of products.