ADVANCED NOTICE: Upcoming changes to the Map Reference Set product formats

Message from SNOMED International.

Dear all

An opportunity has been identified to improve the format of the SNOMED International Map Reference Set products. This will apply to all types of simple and complex Map Reference Sets going forward, including (but not limited to) the SNOMED CT MedDRA Simple Map package, first released back in April 2021.

The existing SNOMED CT map reference sets were originally designed for maps in the direction from SNOMED CT to another code system, manifested by the use of a ‘mapTarget’ string attribute used to represent the code in the other code system. The new and improved map reference set patterns will be introduced with a ‘mapSource’ attribute, in order to more accurately represent maps from other code systems to SNOMED CT.

The refined format provides users with more clarity when using maps of either direction, as well as additional map metadata representing the new refset patterns and correlation values. Users will also benefit from clearer and more predictable naming of the map refsets, as the map reference set concepts have been reviewed and updated to follow the refined description patterns. Please see the links below for the updated technical details including the improvements:

• 5.2.3.1 Simple Map from SNOMED CT Reference Set
• 5.2.3.2 Simple Map to SNOMED CT Reference Set

The first product to be improved using the new designs will be the SNOMED CT MedDRA Simple Map package. After in-depth discussions with the communities’ expert advisory bodies, the users confirmed that their preference was to retain the historical data from April 2021.

It was therefore agreed that the April 2022 SNOMED CT MedDRA Map package will be published as follows:

• …with all new April 2022 content in the improved format
• …with all relevant historical MedDRA data (from April 2021) also in the new format
• …with the historical April 2021 map records that were in the original format inactivated (in order to retire the relevant UUID’s) - the inactivations would likely be published a) in the new package in the new format, and b) in a separate file/package in the original format. However this is still to be confirmed.
• All of this means that the April 2022 file will appear as if the original April 2021 MedDRA release was actually published in the new format. Therefore, the April 2022 MedDRA Release will be published as a complete, consolidated package, with all original data from 2021 plus all new inactivations/changes from the latest cycle presented in the new and improved format.

If you have any questions on the upcoming improvements please email us at This email address is being protected from spambots. You need JavaScript enabled to view it. and cc This email address is being protected from spambots. You need JavaScript enabled to view it.