SNOMED CT® and TermWorks

Release Notes

SNOMED CT Jan 2020 Release

 

 

Copyright Notices

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TermWorks copyright @ 2018, Apelon, Inc.

 

Table of Contents

 

1        Introduction.. 4

1.1       Purpose. 4

1.2       Audience. 4

2        SNOMED CT Updates and Apelon Releases. 4

2.1       SNOMED International Releases. 4

2.2       Apelon Releases. 4

3        Understanding Changes to SNOMED CT in TermWorks. 4

3.1       Categories of Changes. 4

3.1.1       New Concepts. 4

3.1.2       Changed Concepts. 5

3.1.3       Retired Concepts. 5

4        Implementing This Release. 5

4.1       Specific to This Release. 6

4.1.1       New and Changed Concepts. 6

5        Other Changes. 8 


1       Introduction

1.1      Purpose

The purpose of this document is to provide TermWorks users with information on update files produced by Apelon to reflect changes in semi-annual SNOMED CT® releases. It also describes the format of the Infoway Excel files, which identify the changes in a user-friendly style. These files support TermWorks users by providing information on changes made in the new release.

1.2      Audience

This document is targeted at individuals who are responsible for initial mapping and maintaining SNOMED CT code mappings using the TermWorks tool.

2       SNOMED CT Updates and Apelon Releases

2.1      SNOMED International Releases

SNOMED CT is continuously updated to meet the needs of users around the world. Revisions to the international version of SNOMED CT are released twice a year. Each release includes the core components of the terminology (Concepts, Descriptions, and Relationships) and other products to support the implementation and use of SNOMED CT.

 

Updates are driven by users of the terminology and include refinements and additions to SNOMED CT components.

2.2      Apelon Releases

Apelon, an affiliate member of SNOMED International, obtains the new SNOMED CT releases from the National Library of Medicine. The releases are processed by Apelon and made available to Infoway for use in the TermWorks mapping tool twice a year.

3       Understanding Changes to SNOMED CT in TermWorks

When reviewing the changes that occur in a new release of SNOMED CT several factors should be taken into consideration. Changes made to each SNOMED CT component (i.e.: Concept, Description, and Relationship) are based on the change process that was developed by SNOMED International.

3.1      Categories of Changes

There are three types of changes that are included in Apelon’s change files for each release of SNOMED CT. Each type should be reviewed independently. The three types are:

            1. New Concepts

            2. Changed Concepts

            3. Retired Concepts

3.1.1    New Concepts

Semi-annual SNOMED CT releases generally include numerous new Concepts. These new Concepts are based on the RFCs (Request for Change) that were received and approved by SNOMED International. They may not include Concepts that have been approved by Infoway for use in Canada.

 

The information provided in the change file for new Concepts includes:

a)    code – This is the SNOMED CT Concept ID and is the code that identifies the SNOMED CT Concept in future mappings with TermWorks.

b)    name – This is the Fully Specified Name (FSN) from SNOMED CT and is the term that is associated with the Concept ID in future mappings with TermWorks.

c)     Subtype_Hierarchy – This is additional metadata provided by Infoway to assist implementers in filtering the data by context or areas of interest. This is the semantic tag attached to each FSN Concept description and is equal to the information found bracketed in the Name column.

3.1.2    Changed Concepts

SNOMED CT releases generally include numerous changed Concepts. These changed Concepts are based on the requests for change that were received and approved by SNOMED International or through SNOMED International initiated SNOMED CT content projects.

 

The information provided in the change file for changed Concepts will include:

a)    code – This is the SNOMED CT Concept ID and is the code that identifies the SNOMED CT Concept in existing mappings with TermWorks as published in the January 2018 release.

b)    old_name – This is the FSN from SNOMED CT and is the term that is currently associated with the Concept ID in existing mappings with TermWorks. This is the FSN as it existed in the January 2018 release.

c)     new_name – This is the FSN from SNOMED CT as it appears in the July 2018 release. It is the term that will be associated with the Concept ID in future mappings with TermWorks.

d)    Subtype_Hierarchy – This is additional metadata provided by Infoway to assist implementers in filtering the data by context or areas of interest. This is the semantic tag attached to each FSN Concept description and is equal to the information found bracketed in the Old Concept Name column.

e)    Concept Name Change or Other Change - This is additional metadata provided by Infoway to assist implementers in filtering the data to find codes that have had a change in the Fully Specified Name. Changes to this name are indicated with "Name" in the column. Changes to relationships or other changes are indicated by "Other" in the column.

3.1.3    Retired Concepts

When the update is published, it will exclude concepts that were retired. TermWorks only makes active terms available for mapping, so retired Concepts will not be visible using the current version of SNOMED CT with TermWorks. A careful review of these Concepts is required to see if any are currently in use in existing mappings. If retired Concepts are included in current mapping tables, a strategy will be required to replace them. Concepts retired with the current release may still be browsed using the previous release of SNOMED CT.

 

The information provided in the change file for retired Concepts will include:

a)    code – This is the SNOMED Concept ID and is the code that identifies the SNOMED CT Concept in in existing mappings with TermWorks and the Concept that has been retired.

b)    name – This is the FSN from SNOMED CT and is the term that is associated with the Concept ID in existing mappings with TermWorks. It represents the term for the Concept that has been retired.

c)     Subtype_Hierarchy – This is additional metadata provided by Infoway to assist implementers in filtering the data by context or areas of interest. This is the semantic tag attached to each FSN Concept description and is equal to the information found bracketed in the Name column.

4       Implementing This Release

Projects that have not previously used TermWorks may begin to use the new version immediately.

 

Projects that have already begun mapping in TermWorks will need to complete a careful quality control review of the new release to determine how the changes will impact the work they have completed so far. Some things to consider:

 

  1. When reviewing maps, choose between the versions of SNOMED CT to evaluate specific concepts. The January 2020 and the July 2019 versions of SNOMED CT are currently available for mapping as well as the September 2019 version of the Canadian Extension.
  2. Review the Concepts that have been retired to see if they are currently in use. Alternate Concepts will need to be chosen for retired Concepts.
  3. Review the Concepts that have been changed to ensure the change does not impact the current use of that Concept in existing mappings. Details regarding relationship changes have not been provided by Apelon. In instances where the Old Concept Name and the New Concept Name are the same, it can be assumed that a relationship change has been made.  These will need to be investigated using a SNOMED CT browser or other software.
  4. Review new SNOMED CT Concepts to determine if they can be used to solve any current mapping problems.

4.1      Specific to This Release

4.1.1    New and Changed Concepts

There were no anomalies for new Concepts added to the Jan 2020 SNOMED CT release. There were 3051 new codes added, dispersed across several hierarchies.

 

  • There were 2760 concepts that were changed in this release.
    • Of those, 1108 had a name change (e.g. Majority of the changes were made in the hierarchy (disorder), changing the concept name with an addition of ‘precisely’ and ‘conventional release oral tablet’ such as ‘Product containing only acetazolamide 250 mg/1 each oral tablet (clinical drug)’ to ‘Product containing precisely acetazolamide 250 milligram/1 each conventional release oral tablet (clinical drug)’).
    • 68 changes were made in the hierarchy (medicinal product), changing the name such as ‘Product containing diatrizoate (medicinal product)’ to ‘Product containing amidotrizoate (medicinal product)’)
    • 1108 concepts had a name change in this release.
    • 1652 concepts had an other change in this release
    • The remaining terms should be reviewed in the SNOMED CT browser if they are being used in your organization.

 

While the new Concepts added by SNOMED International have been assigned SNOMED CT Identifiers (SCTIDs) that are a maximum of 11 digits long, content created by other countries has also been added. Examples of some of these Concepts are provided in Table 1. These SCTIDs are up to 18 digits long.

 

CODE_IN_SOURCE

NAME

107881000119100

Advanced collapse of scapholunate joint due to osteoarthritis (disorder)

12265261000119102

Benign extra-axial hygroma (disorder)

Table 1

This variance in SCTID length will not impact the use of TermWorks, but may be an issue in Excel depending on the format of the Excel cell. By default, Excel comes with a built in number precision of 15 digits. To prevent numbers longer than 15 digits from displaying incorrectly or from having them round up, Excel cells need to be formatted prior to starting a mapping exercise. To accommodate numbers up to 15 digits, use a ‘Number’ format, to accommodate numbers greater than 15 digits, use ‘Text’ format. When Excel cells are not formatted correctly, the SCTID may appear as shown in Figure 1.

 

Figure 1

With these longer SCTIDs, simply extending the column width as shown in Figure 1 is not sufficient and the cell (or column) will require specific formatting. The property should be formatted to indicate the content is a number in order to properly display the SCTID when it contains 15 or less digits. The change in format for numbers of 15 digits or less can occur before or after the mapping. If the number contains more than 15 digits, using the number format will not work. See Figures 2 and 3 for a properly formatted cell for numbers up to 15 digits.

 

Figure 2 Formatting the cell to ‘Number’

Figure 3 The 15 digit number now displays

 

Because of the built in precision of Excel, the only way to use numbers that are longer than the built in precision of 15 digits is to first format the cell as ‘Text’. This will ensure that the longer numbers are displayed without rounding. Figure 4 shows the result of formatting the cell as a number; the last 3 digits have been rounded to 0.

 

Figure 4 Cells formatted as Number

If the formatting is then changed to Text, the number remains rounded as shown in Figure 4. Figure 5 shows how the number is displayed if the cells are formatted as Text prior to mapping.

Figure 5 Cells formatted as Text

 

When using long SCTID numbers, rounding errors may occur when data is copied and pasted from one file format to another. For more information on rounding in Microsoft products, see the following web page:

 

http://support.microsoft.com/kb/214118

5       Other Changes

The Apelon SNOMED CT Change File spreadsheet contains an additional tab to support the SNOMED CT Concepts that have been retired. This tab should be reviewed to see if Concepts that are used in your maps have been affected.

 

Users of SNOMED CT should consult Infoway’s Terminology Gateway for any additional documentation from SNOMED International included in the SNOMED CT release package.

                                                        

Questions and comments regarding the Apelon release of SNOMED CT in relation to TermWorks can be made via the support email:

 

[email protected]

 

Additional information about TermWorks is available on Infoway’s InfoCentral.

 

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