Change to Effective Time for International Edition Starting 1 September 2023

After consultation with the community, SNOMED International has changed the date of the effective time for the International Edition from the last day of each month, to the first of each month.  

The effective time for the “January” edition will be 1st January.

The effective time for the “July” edition will be 1st July. 

The July 2023 International Edition was the last to be published with effective time of the last day of the month.

Further details about this change can be found in the Q&A blog post. 

Inactivation of 9258009|Gravid uterus structure (body structure)|

This concept will be inactivated, content that is modeled with this concept will be remodeled with a site of 35039007|Uterine structure (body structure)| along with occurrence <<307159006|Pregnancy time period (qualifier value)|.  

The domain of 246454002 |Occurrence (attribute)| has been extended in the October 2023 release to include << 71388002 |Procedure (procedure)| to support these content changes. Content areas that will be updated include 386811000|Fetal procedure (procedure)| and 386637004|Obstetric procedure (procedure)|.

Inactivation of Concepts Specified Male/Female in Descriptions

Subtypes of 67770001 |Male mammary gland structure (body structure)| and 91532001 |Female mammary gland structure (body structure)| and their associated disorder and specimen concepts.  Further information is available here (Confluence log in required).

Update for Concepts Using 'Caused by'

Clinical finding concepts containing "Caused by" in their FSN will be reviewed and will be updated (if applicable) according to the editorial guidelines related to causation here. 

There is one area where work is still in progress:  

• Clinical finding caused by radiation.

Commencing Q4 2023 International Releases until completion.

Updates to the Inactivation Reason and Historical Association for 'On Examination' and 'Complaining of' Inactive Content

Many of the 'on examination' and 'complaining of' concepts were previously inactivated with the inactivation reason of |Moved elsewhere| with a historical association value |Extension Namespace 1000000|.

This content will be updated with an inactivation reason of |Non-conformance to editorial policy| and a historical association of |Alternative| to a suitable international concept. 

Ethnic/Racial Group Social Context Content Inactivation

The subtypes of 372148003 |Ethnic group (ethnic group)| and 415229000 |Racial group (racial group)| will be inactivated as they are out of scope for the International Edition.  A briefing note is available here.

Patient/Subject concepts in the Clinical finding and Procedure Hierarchies

Concepts in the Clinical finding and Procedure hierarchies that contain the explicit context of patient or subject will be inactivated and replaced with concepts without this explicit context. For further information please see briefing note.

The Senior Management Team (SMT) recently agreed on a proposed solution to resolve the duplication between the evaluation procedure and observable entity hierarchies. The resolution includes moving the majority of the evaluation procedures to the observable entity hierarchy while retaining the original concept id during the move.

The semantic tag will be updated from evaluation procedure to observable entity, and updates in terming and modeling to align with the observable entity model are expected. This move will allow for concepts of multiple granularities to be classified in a single hierarchy.

Non-defining annotations for “order only,” “observation only,” or “both order and observation” may be added to the concepts to assist with certain use cases. Note that some content areas of evaluation procedures such as panels and procedure methods will not be addressed at this time.

A projected timeline of changes will be developed and shared with the community. Editorial and implementation guidance will be provided with this project. Please see the briefing note for further information.

To be determined

Inactivation of 277132007|Therapeutic procedure (procedure)

The concept 277132007 |Therapeutic procedure (procedure) will be inactivated with the inactivation reason of Outdated and a replacement association target of 71388002 |Procedure (procedure)|. The nearly 2000 descendants will be reviewed as to the appropriateness of either the Has intent (attribute) of Therapeutic intent, or a Method (attribute) of Therapy - action.

For further information please see briefing note.

Remodeling of Subtypes of 128422009 |Destruction using electrical energy (procedure)|

Procedures using electrical energy classified as Diathermy (procedure) and Electro X (procedure) will be remodeled and reclassified according to the main action performed and the expected result of such action.

424244007 |Using energy (attribute)|= 18213006 |Electricity (physical force)| will be added with and updates to the descriptions.

Further information about these change is available here.

Inactivation of Procedure Concepts with AND/OR in FSN.

Classification derived concepts under 71388002 |Procedure (procedure)|using AND/OR in FSN will be inactivated in alignment with Editorial Guidance. As needed, new concepts will be created to substitute inactivated concepts without ambiguity.

Subtypes of 1263452006 |Anesthesia and/or sedation procedure (procedure)| and 108290001 |Radiation oncology AND/OR radiotherapy (procedure)| will be inactivated or modified only if needed to align with other inactivations.

Remodeling of Non-Surgical Drainage Procedures

Normalization of attributes used for Procedure site direct/indirect, Indirect/direct morphology and Direct/indirect substance will be performed for concepts modeled with 260686004 |Method (attribute)|= 129289008 |Drainage - action (qualifier value)|.

Alignment and normalization is needed for subsequent remodeling of Surgical drainage procedures.

Update Model and Descriptions for Fetal, Neonatal and Perinatal Jaundice Disorder Concepts

A review of content in this area has been undertaken.

The semantic tag for concepts representing “Jaundice due to X” and “Jaundice caused by Y” will be updated from (disorder) to (finding); their modeling and descriptions will be updated accordingly.

Concepts of type “Jaundice due to and co-occurrent with Z” will retain “is_a” relationship to “Z (disorder)”; their semantic tag will be retained as “disorder”.

The "Occurrence" attribute value for perinatal jaundice findings will be updated to 1156671008 |Maternal perinatal period (qualifier value)|. This change is required to reflect the fact that these findings are related to the mother, who has the jaundice, rather than the fetus. 

Inactivation of 168123008 |Sample sent for examination (situation)| and Descendants

168123008 |Sample sent for examination (situation)| and its ~90 descendant concepts will be inactivated as out of scope of the international release of SNOMED CT.

Urinary Bladder

Following feedback from translation, descriptions for concepts that contain the word 'bladder' and the site of 89837001|Urinary bladder structure (body structure)| will be updated to include 'urinary' in the FSN and PT, for example:

126885006|Neoplasm of bladder (disorder)

will be updated to

126885006|Neoplasm of urinary bladder (disorder).

Update for 73632009 |Laparoscopy (procedure)| and Subtypes 

There will be a bulk update to align 73632009 |Laparoscopy (procedure)| and subtypes with the template here: https://confluence.ihtsdotools.org/display/SCTEMPLATES/Laparoscopy+%28procedure%29+-+Draft

These changes include the addition of INCISION ROLE GROUP and INSPECTION ROLE GROUP for all Laparoscopic procedures. 

Inactivation of Concepts that state Delivered/Not delivered

Obstetric content that conflates the delivery status with the disorder of the mother that prompted the admission to hospital will be inactivated.

There are 250 concepts that state the delivery status of the mother within the FSN:

• 198905007 |Placenta previa with hemorrhage - delivered (disorder)|
• 198906008 |Placenta previa with hemorrhage - not delivered (disorder)| 

These concepts are classification derived and are used to record whether the baby was, or was not delivered during that inpatient stay for the care of the mother who has placenta previa with a hemorrhage.

2.

Update for 399248000 |Procedure related to anesthesia and sedation (procedure)|

745638006 |Injection of anesthetic agent (procedure)| and its 283 subtypes will gain a supertype of 399097000 |Administration of anesthesia (procedure)|. 

Inactivation of 415360003 |Severe acute respiratory syndrome-related coronavirus (organism)|

To resolve ambiguity for 415360003 |Severe acute respiratory syndrome-related coronavirus (organism)|, this concept will be inactivated as ambiguous. New concepts will be created to represent the associated strain and species.

840533007 |Severe acute respiratory syndrome coronavirus 2 (organism)| will be a sibling of the “Severe acute respiratory syndrome (SARS) coronavirus” strain and a subtype of the “Severe acute respiratory syndrome-related coronavirus” species.

Current children of 415360003 |Severe acute respiratory syndrome-related coronavirus (organism)|, which represent Severe acute respiratory syndrome (SARS) coronavirus strain subtypes will be inactivated using "Outdated component" as the inactivation reason with a "Replaced by" association to the concept representing “Severe acute respiratory syndrome (SARS) coronavirus."

Details of the change can be found in this Briefing Note.

Planned Inactivation of Concepts in the 260299005 |Number (qualifier value)| Hierarchy

Following the deployment of the concrete domain functionality in SNOMED CT, concepts in the 260299005 |Number (qualifier value)| hierarchy are no longer necessary and plans have been made for their inactivation.

To provide adequate time for any national extension or implementation affected by this change, concepts in the 260299005 |Number (qualifier value)| hierarchy will be inactivated in the January 2023 International Release.

Concepts will be inactivated with reason “Non-conformance to editorial policy” and no historical relationship or replacement concept will be provided.

Exceptions:

118586006 |Ratio (property) (qualifier value)| and descendants have been relocated to 118598001 |Property (qualifier value)| hierarchy.

272070003 |Ordinal number (qualifier value)| and descendants have been relocated to 362981000 |Qualifier value (qualifier value)| hierarchy.

A briefing note will also be distributed to selected Advisory and Project Groups.

Please contact info@snomed.org with any inquiries.

Remodeling of 771527003|Structure of synovial sac (body structure)| and Subtypes

The content in this area is being updated to align with this model.

Inactivation of 118222006 |General finding of observation of patient (finding)|

118222006 |General finding of observation of patient (finding)| is a high level finding with little clinical value.  The concept will be inactivated with an inactivation target of Clinical finding.  Descendants count is 4237 concepts. 

Update to 307159006|Pregnancy time period (qualifier value)| and Subtypes

Concepts referring to temporal periods for pregnancy and birth (307159006 Pregnancy time period (qualifier value) and subtypes) will be updated with the addition of a small number of concepts to make this area of content more comprehensive.

A new concept which explicitly covers 'maternal antenatal and/or intrapartum and/or postpartum period’ will be added.

Definitions will be added to aid modeling and interpretation.

Update to MRCM

Extend the range of 719722006 |Has realization (attribute)| by including 71388002 << |Procedure (procedure)|, << 272379006 |Event (event)|, << 404684003 |Clinical finding (finding)|.

Please see here

Inactivation of "X by body site" concepts in various hierarchies

Concepts that include "X by body site" in multiple hierarchies are being inactivated, e.g., 371571005 |Imaging by body site (procedure)| and 301810000 |Infection by site (disorder)|, because they are classification groupers with no clinical use.

Neoplasm of Connective and Soft Tissue Disorders

Around 30 concepts which include “neoplasm of connective and soft tissue" in their FSN will be inactivated as "Classification derived component." 

Measurement Findings

The next set of changes for measurement findings content will involve the positive and negative results content (~150 concepts). Measurement findings concepts which include 'positive' or 'negative' in the FSN will be updated as follows:

1) The FSN and PT will be updated to include 'detected' or 'not detected.' Existing descriptions with 'positive' or 'negative' will be retained as synonyms.
2) The Has interpretation value of 10828004 |Positive (qualifier value)| or 260385009 |Negative (qualifier value)| will be updated to 260373001 |Detected (qualifier value)| or 260415000 |Not detected (qualifier value)|.

Please see the briefing note (20221116 BN Positive_Negative measurement findings.pdf) for more information.

Metastatic Content with 'Involving' and 'Metastasis to X of Unknown Y'

Approximately 75 disorder concepts of the type 'Malignant tumor involving [x structure] by [separate] metastasis from [y structure]' and 30 disorder concepts of the type 'Metastasis to [x structure] of unknown primary' will be inactivated.

Examples:

369554006 Malignant tumor involving right fallopian tube by separate metastasis from left fallopian tube (disorder)
285643007 |Metastasis to adrenal gland of unknown primary (disorder)|

The current Editorial Guidance indicates that the primary malignancy and the metastatic malignant neoplasm should be recorded using two separate SNOMED CT concepts, and these replacements will be provided as inactivation target values, and if not available they will be created.

Remodel 16356006|Multiple pregnancy (disorder) to Become Subtype of 77386006 |Pregnancy (finding)|

16356006|Multiple pregnancy (disorder) will be updated to a clinical finding with a semantic tag of (finding) and a subtype of 77386006 |Pregnancy (finding)|.

Current subtypes of 16356006|Multiple pregnancy (disorder) will be reviewed as some subtypes should retain the semantic tag ‘disorder’ where the concept meets the criteria of being always and necessarily an abnormal clinical state.

A new parent will be assigned designated by whether the semantic tag has been changed.

Primary and Metastatic Project - New Primary Malignancy Disorders

Approximately 150 new primary malignancy disorders will be added to SNOMED CT.

Inferred subtypes of 372087000 |Primary malignant neoplasm (disorder)| that were assigned by the classifier based on the morphology hierarchy (now revised), but which did not state primary in the FSN ('agnostic') have been reviewed.  

These previous subtypes of 372087000 |Primary malignant neoplasm (disorder)| will have a new subtype concept added that states 'primary' to provide an option for selection by clinicians.

Inactivation of 307844003 |Minor surgery status (finding)| and Subtypes

Concepts that have explicit context should be in the situation hierarchy. Therefore 307844003 |Minor surgery status (finding)| and 5 subtypes with context "done" + a procedure will be inactivated.

One concept 314471005 |Minor surgery done (finding)| will be inactivated and replaced by 1268934004 |Minor surgery done (situation)|.

Concepts in various hierarchies (including Procedure, Clinical finding, Observable entity, Event and Specimen), which are defined by the stated attribute value of "105590001 |Substance (substance)|" are being reviewed.

Many of these concepts are being remodeled by removing the attribute/value relationship—provided that this change doesn’t result in a change to the meaning of the associated concepts. Some of these concepts may need to be remodeled with a more specific substance.

Some of the grouper concepts will be inactivated—specifically the groupers that are classification derived and/or have only one subtype. This change is part of the Substance-Drug project and will allow for the correct subsumption of the subtypes, if and once the attribute values are changed to subtypes of 373873005 |Pharmaceutical / biologic product (product)|.

Inactivation of 6920004|Defect (morphologic abnormality)|

6920004|Defect (morphologic abnormality)|is planned for inactivation. 286 concepts currently modelled with 6920004|Defect (morphologic abnormality)| will be reviewed and remodelled; this may include inactivation and replacement.

Please see the briefing note for further details.

Inactivation of Measurement Finding Concepts

The following concepts will be inactivated as they do not comply with editorial guidance:

• • Blood glucose finding concepts with the numeric value or range precoordinated, e.g., 166915000 |Blood glucose 1.5-2.4 mmol/L (finding)| - 7 concepts.
  • Urine pH finding concepts with the numeric value precoordinated, e.g., 167309000 |Urine pH = 6.5 (finding)| - 7 concepts.
  • 107651007 |Quantity finding (finding)| and 13 subtype concepts.
  • "X in sample" finding concepts, e.g., 275791007 |Urea in sample (finding)| - 9 concepts.

Planned Inactivation of Subtypes of 129284003 |Surgical action (qualifier value)|

As part of the Quality Initiative, a review has been undertaken of the 129284003 |Surgical action (qualifier value)| hierarchy which has identified:

• 36 concepts with no usage or descendants.
• 4 concepts with 3 or less descendants and no usage.
• 5 concepts with low usage and less than 2 descendants with no usage.

As a result of this review, 45 concepts in the qualifier value hierarchy that are descendants of 129284003|Surgical action (qualifier value)| will be inactivated. The complete list of concepts can be accessed here.

Primary and Metastatic Project - New Metastatic Morphologic Abnormality Concepts

Metastatic disorders will be defined by their specific metastatic neoplastic morphologic abnormality concepts, and new metastatic morphologies are being added to the international edition of SNOMED CT as needed. In cooperation with the Netherlands extension of SNOMED CT, SNOMED International will be promoting certain of their existing metastatic morphology concepts to the International release to be used to model new metastatic disorder concepts. 

Update to MRCM

The domain and proximal primitive refinement will be updated to the MRCM of situations of findings and procedures.  The existing exclusion constraints for domains will be removed. The "associated finding" and "associated procedure" will be added as mandate requirements, and the contexts will be removed.  Further details are available 
here and here.

Addition of AJCC Cancer Staging Content

New subtypes of 1222584008 |American Joint Committee on Cancer allowable value (qualifier value)|

Based on requests from several member countries through the Content Managers Advisory Group, AJCC have now approved addition to SNOMED CT of new cancer staging content as part of a joint collaborative process agreed between both organizations.

Change for Clinical Drug Concepts Containing Pancreatic Enzymes

Clinical drug concepts in the International Release containing pancreatic enzymes will be modeled based on the discrete enzymes; because of variability between real clinical drugs, synonyms representing a total amount in a particular product will not be included in the International Release.

The editorial guide and existing content will be reviewed and updated accordingly in a future release.

Plan to Move the International Monthly Release Date to the First of Each Month

After consultation with the community, SNOMED International will be changing the dates of the International Edition from the end of each month, to the first of each month.  This will mean that in addition to all of the other months, the “January” release will move from 31st January to the 1st January, and the “July” release will move from 31st July to 1st July each year.  

Further details of this proposal can be found here (https://www.snomed.org/news/blog%3A-the-snomed-ct-international-edition-to-be-published-on-first-day-of-each-month), however if you have any concerns in the meantime please provide feedback to release@snomed.org as soon as possible. 

"Did not attend X" or "Attended X" Clinical Finding Concepts

Around 30 "did not attend X" or "attended X" findings concepts, e.g., 390923003 |Did not attend cardiac clinic (finding)|, will be inactivated from the international release as they are administrative concepts.

Around 20 "did not attend X" or "attended X" situation concepts, e.g., 310352003 |Mammography not attended (situation)|, will be inactivated from the international release as they are out of scope of this hierarchy.

Measurement Findings

The six false positive and false negative measurement findings, e.g., 274684006 |False-positive serological test for syphilis (finding)|, will be inactivated with reason of Nonconformance to editorial policy.

Drug Content Analysis Project (DCAP) - Addition of Anti-Infective Clinical Drug Concepts 

DCAP was launched in September 2022 to identify clinical drug concepts that are published in participating National Release Center extensions and that are eligible for promotion to the international release (supported by appropriate references to authoritative source material).

Concepts that are already published in the Norwegian drug extension have been reviewed by multiple countries participating in the group and content eligible for promotion to the international release of SNOMED CT has been identified.

Approximately 100 concepts will be promoted to the international release and corresponding concepts for Medicinal Product (MP) 'containing only', and Medicinal Product Form (MPF) 'containing only' imported from Norway if missing. MP 'containing' concepts will be created in the international release as required.

Clinical drugs modeled with dose form 421366001 |Tablet for conventional release oral suspension (dose form)|

The dose form 421366001 |Tablet for conventional release oral suspension (dose form)| will be updated with the new Preferred Term 'Dispersible oral tablet'. This aligns with the EDQM standard.

37 clinical drugs that are defined with a dose form of  421366001 |Tablet for conventional release oral suspension (dose form)|  will have a new Preferred Term created for 'dispersible oral tablet' and the existing PT made a synonym.

Update to MRCM

1142142004 |Has pack size (attribute)|is an attribute that is used for modeling real clinical drugs in a national extension (not for use in the international edition of SNOMED CT). The current MRCM prevents national extensions from using a decimal to define a pack size (for example, a 3.5 milliliter bottle) as it limits the attribute range to whole integers only.

The MRCM will be changed for Has pack size (attribute)|from Integer to Decimal.

Resolution of Dose Form Inconsistency for 421366001 | Tablet for conventional release oral suspension (dose form)

The Preferred Term (PT) of 421366001 | Tablet for conventional release oral suspension (dose form) | will be updated from “tablet for oral suspension” to “dispersible oral tablet.”

This is in line with EDQM (also national data sets) where a dispersible tablet is equivalent to a tablet for oral suspension.

The PT of 37 clinical drugs (CDs) that currently have a mixture of names will be updated to all use “dispersible oral tablet”. Therefore, users will be able to search for and translate these CDs more effectively.

New Subtypes of 1155866009 |Messenger ribonucleic acid of severe acute respiratory syndrome coronavirus 2 encoding spike protein (substance)|

New subtypes will be added to 1155866009 |Messenger ribonucleic acid of severe acute respiratory syndrome coronavirus 2 encoding spike protein (substance)| including:

• "SARS-CoV-2 mRNA encoding B lineage spike protein" (i.e. "SARS-CoV-2 mRNA encoding original strain spike protein")
• Severe acute respiratory syndrome coronavirus 2 mRNA encoding BA.1 lineage spike protein
• Severe acute respiratory syndrome coronavirus 2 mRNA encoding BA.4/BA.5 lineage spike protein

These concepts will be created to meet the requirement for creation of bivalent vaccines (usually containing original strain + an omicron variant). In addition, creation of "SARS-CoV-2 mRNA encoding original strain spike protein" will allow for accurately representing monovalent vaccines containing "SARS-CoV-2 mRNA encoding B lineage spike protein" (original strain)."

Update Hierarchy 90708001 |Kidney disease (disorder)|

As part of the Quality Initiative Project, work has commenced on 90708001 |Kidney disease (disorder)|. Work is being undertaken in stages and upcoming sub-hierarchies will be posted here as the work progresses:

• 236423003 |Renal impairment (disorder)| -  completed.

The remaining content areas in this hierarachy will be reviewed and updated as part of the QI project. 

Concepts with "...attend.. X"

Around 40 "attends X" or "attending X" findings concepts, e.g., 160766005 |Midwife attends 14-16 days post-discharge (finding)| will be inactivated from the international release as they are administrative concepts. 

Update to MRCM

Extend the domain of 246454002 |Occurrence (attribute)| by including << 71388002 |Procedure (procedure)|.

The following is the expected MRCM range after the change.

246454002 |Occurrence (attribute)| << 272379006 |Event (event)| OR << 404684003 |Clinical finding (finding)| OR << 71388002 |Procedure (procedure)|

Review of CRS Requests in “Awaiting agreement compliance” Status from SNOMED CT – LOINC Cooperation Project

CRS requests in “Awaiting agreement compliance” status due to the previous cooperative agreement between SNOMED International and Regenstrief Institute, Inc. have been reviewed in light of the new cooperative agreement, the latest SNOMED CT Editorial Guide, and the latest CRS guidance documents. Concepts deemed in scope are being added.

Inactivation of Subtypes of 125676002|Person (person)|

The following concepts will be inactivated:

444145006 |Partner in relationship with subject (person)| - historical association to 262043009 |Partner in relationship (person)|

444210007 |Cohabitee in relationship with subject (person)| - historical association to 394921008 |Cohabitee (person)|

The Editorial Guide states that the Subject relationship context (attribute) is used to specify the subject of the Clinical finding or Procedure being recorded, in relation to the subject of the record; therefore, the above two concepts are unnecessary.

"X result not back (situation)" concepts

Four concepts of the type "X result not back (situation)," e.g., 168709001 |Soft tissue X-ray result not back (situation)|, will be inactivated as they are out of scope for the international edition of SNOMED CT.

October 2023 International Release

Update Hierarchy 271903000|History of pregnancy (situation)

Content relating to past pregnancy history of the subject of the record will be remodeled to subsume under the parent 271903000|History of pregnancy (situation)|.

Fully specified name and preferred term will be updated to explicitly state 'Past pregnancy history of.'

161811009|History of perinatal fetal loss (situation)| and 726626004|History of neonatal death (situation)| will be inactivated and replaced by concepts:

Past pregnancy history of neonatal death (situation)
Past pregnancy history of late neonatal death (situation)
Past pregnancy history of early neonatal death (situation)
Past pregnancy history of perinatal death (situation)
Family history of perinatal death (situation)
Family history of neonatal death (situation)

October 2023 International Release

Update to MRCM

The MRCM for Administration of substance via specific route (procedure) is no longer needed. The domain 433590000 |Administration of substance via specific route (procedure)| is replaced by a new concept 1285465008 |Administration via specific route (procedure)|

Instances of “Administration of substance via X specific route (procedure)” have been replaced with concepts of type “Administration via X specific route (procedure)”. This change is part of the Substance-Drug project and allows for the unambiguous subsumption of the subtypes, if and once instances of 363701004 |Direct substance (attribute)|are modeled with subtypes of 373873005 |Pharmaceutical / biologic product (product)|. 

Update for Concepts Using 'Caused by'

Clinical finding concepts containing "Caused by" in their FSN will be reviewed and will be updated (if applicable) according to the editorial guidelines related to causation here. The main focus of the review will be the following category of concepts:

• Concepts containing "Caused by" in their FSN that have a synonym (including PT), which contains “Due to”
• Concepts where FSN contains "Caused by" and "Due to"

Additional content update may become applicable while reviewing these concepts for example: 

• Concepts that do not contain “Caused by” or “Due to” in their FSN, but contain one of these terms as their preferred terms
• Concepts containing “Due “to in their FSN that have a preferred term which contains “Caused by”.
• Poisoning caused by (due to) organism sting or bite. 

Review of 35331000 |Toxic substance (substance)|

35331000 |Toxic substance is an ambiguous concept and will be inactivated; it can refer to any substance that has been used in amount that is harmful for health (including medication), a toxin, heavy metals, or preservatives--not all of these are currently children of 35331000 |Toxic substance (substance)|. In addition, concepts defined by 35331000 |Toxic substance (substance)| will be reviewed;  their terming and modeling will be updated where applicable, specifically where the FSN and attribute/value do not match.

Update hierarchy 263026000|Dislocation of perilunate joint (disorder)|

A new supertype concept 1290805004 |Dislocation of joint of lunate (disorder)| will be added with subtypes: 

• 1290885002 |Dislocation of lunate bone (disorder)|
• 263026000 |Dislocation of perilunate joint (disorder)|

Subtype content will be remodeled. A text definition will be added for 263026000 |Dislocation of perilunate joint (disorder)|.

The FSN for 264132003|Structure of perilunate joint (body structure)| will be updated to 264132003 |Structure of joint of lunate (body structure)|.