Introduction

The 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 International Health Terminology Standards Development Organisation (IHTSDO^®) maintains the SNOMED CT technical design, the content architecture, the SNOMED CT content (including the concepts table, the descriptions table, the relationships table, a history table and ICD mappings), and related technical documentation. 

This document is intended to give a brief description, background context, explanatory notes on the SNOMED CT International Drugs and Substances project and the resulting Content Preview Release package, which will be published on 9-Feb, 2018 and as needed throughout the current release cycle. 

Audience for this document

This document should be read by all those who will be reviewing or submitting questions or comments related tot he Content Preview, including participation in any follow up meetings. 

Scope and Purpose

The scope of the SNOMED CT International Drugs

Role chain and DL features to support classification of the product hierarchy and modeling of product roles have been deployed into production.

A preview of content changes will be distributed for external review 9-Feb. It is expected to include a significant number of examples of the following types of content updates:

• Product Groupers including chemical structure, dispositions and combined chemical structure-disposition groupers that have been remodeled using proximal primitive modeling pattern and have terming normalized. 
• Dose forms hierarchy remodel with additional content.
• MPs and MPFs updated to proximal primitive modeling pattern and have terming normalized.
• CDs will be excluded from the 9-February content preview.
• Updated Editorial Guide draft and updated Product Model Specification.

Outstanding modeling issues:

• Ingredient count modeling was agreed and approved by Head of Terminology on 08-FEB. Supporting work includes development of Editorial Guidelines, technical implementation and batch updates will be made available in the next preview.
• Concentration strength model is being worked on and is target for modelling by the end of February. Supporting work includes development of Editorial Guidelines, technical implementation and batch updates will be made available in the next preview.
• Product roles discussion has started and is target for modelling by the end of February. Supporting work includes development of Editorial Guidelines, technical implementation and batch updates will be made available in the next preview.

The scope of the SNOMED CT International Substances project

Role chain and DL features to support Modification groupers have been deployed and the first flattening has been successfully carried out.

Work on Jul2018 release has progressed well with a planned Alpha release scheduled for 09-February 2018.

• Disposition Groupers had been updated, modelled and fully defined in Jan2018 release, they are being updated to proximal primitive and will be included July 2018 release.

• Role Groupers have been reviewed. Some concepts have been inactivated and others replaced. 

• Additional Disposition concepts and Disposition Groupers have been created.

• Structure Groupers will be retained as primitive concepts.

• Additional Structural Groupers have been created.

• Combined Groupers ( Structure + Disposition) will be remodeled as we progress, the volume for this category is small.

• Miscellaneous types of groupers will be addressed on a case by case basis

Radiopharmacy concepts have been remodelled and the terms updated to provide consistent representation of these concepts

Roles decision is to be made for further progress of roles groupers.

The Editorial Guidelines are being updated following Project Group review in December 2017. Further updates to these guidelines are planned as work progresses.

Release content

Content detail

Detailed documentation regarding changes to the Substance and Drug hierarchies that are in scope to be reviewed for this Content Preview are located on the project Confluence sites:

• https://confluence.ihtsdotools.org/display/IAP/Drug+Model+Working+Group+-+Directory
• https://confluence.ihtsdotools.org/display/IAP/Reference+Documentation+-+Substances

Please note that comments and questions submitted related to content not specifically identified as in scope for this Content Preview will be rejected.

Effective date

Is not applicable for this Content Preview. However the content will be made available for your review from 09-FEB to 28-FEB.

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.