Jim Case

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Jim Case

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Jim Case 

SNOMED currently has extensive editorial guidance on terming patterns for disease combinations that involve the distinction of causal and temporal relationships between conditions.  One scenario that has not been adequately addressed is the representation of variably present clinical manifestations of a syndrome.  Syndromes often have multiple associated clinical manifestations that are variably present during the disease process or progression.  It is important to be able to specifically call out these conditions as being extant at the time of recording, i.e. they are not definitional for the syndrome in general, but are definitional at the time of clinical presentation.  An example is Bechet's disease, for which the pathognomic clinical presentation is oral ulcers, but other inflammatory conditions can occur with the disease (e.g. skin rashes, uveitis, arthritis, etc.).   

Current editorial guidance (Disorder Combination Modeling) suggests the use of "X with Y" as the FSN terming pattern.  Prior discussions have suggested that the use of terms such as "X with Y" and "X in Y" are too vague to represent the association of the condition with the syndrome.  The use of "X due to Y" has also been considered inappropriate as the condition is not caused by the syndrome, but is a variably present component of the syndrome.

• Jim Case to provide a list of affected concepts

Nicola Ingram 

An updated Briefing note for transplantation procedures of both solid organs and tissues is provided.  An updated status report is also included below.

Discussion: Please read the short update document for today's EAG  attached for details (including numbers involved and inactivations). Excluded transplant procedure areas are described.

Here is a summary of the model:

Solid organ transplant procedures:

260686004 |Method (attribute)| = 410820007 |Surgical transplantation - action (qualifier value)|

405813007 |Procedure site - Direct (attribute)| = << 24486003 |Structure of transplant (body structure)|

363701004 |Direct substance (attribute)| = << 422285003 |Transplant solid organ (substance)|

For glands and viscera if required a new subtype of 24486003 |Structure of transplant (body structure)| was created. If no specific graft substances existed 261571005 |Tissue graft - material (substance)| was utilised (or 15879007 |Autograft (substance)|, similarly for allograft etc). See 119911006 |Salivary gland transplantation (procedure)| illustration on EAG update document. Any feedback comments?

The majority of tissue transplant procedure concepts (eg. nerves, muscle, tendon ,skin),  were inactivated as duplicate to the grafting procedure where this existed, or a new grafting procedure created. The transplant procedure was aded as a synonym to the grafting procedure and a normal body structure used as the procedure site plus a direct substance relationship as described above for glands and viscera.

Questions to be sent to Nicola Ingram and Jim Case for discussion and clarification at a future EAG call.

23 Sep 2024 

Access has been granted to the SNOMED Terminology server and some comments have been received:

Jeff Pierson 

Specifically addressing your comments after review of the content changes in the TS Browser: Transplantation model noted. Use of the body structure of "transplanted <X>" makes sense to avoid issues you outlined.

1. I don't think the “Direct substance” is needed (it's redundant to the body structure), unless it provides additional information: like "Allograft", "Tissue graft - material", etc.
2. I think a simplified model using only "Allograft" is better than to a pre-coordinated substance, because it is sufficient and limits creation of new content.
3. The model and approach look reasonable.

Impact of the suggested revisions:

• Removing the Direct substance (attribute) relationship when it is redundant i.e. does not add additional information. Rationale: we are using << 24486003 |Structure of transplant (body structure)| now to specify transplant material
• Removing any new << 261571005 |Tissue graft - material (substance)| that I created that are not now required

Comment from Matt Cordell 

Transplant Procedures - What is the issue with the current remodelling is trying to solve? (It’s unclear why a new model is being proposed, and what the benefits of the new model are)
Apologies for not replying to this one  sooner. I must have missed it. I haven’t had a chance to look at the modelling in authoring platform yet.
Solid Organ:
          What is the purpose of the property “Directsubstance(attribute)=<<422285003|Transplantsolidorgan(substance)|”. Would classification be different without it?
Tissue transplants –
          I think cleaning up the duplication/ambiguity around graft/transplants is good.
          “Tissue transplant procedures will not use << 24486003 |Structure of transplant (body structure)| for the Procedure site - direct relationship, to prevent having to create numerous new transplant body structure concepts, but instead will use normal body structures”
           If it’s OK here, why can’t this be done for Solid organ transplants also?
            It would be valuable to actually model what the graft material is. Especially when it’s removed/transplanted from another site.
           Are these always “autoimplants” ? (if so they presumably always include an exicsion of the “donor” material)

2024-09-23:

The reason for the remodeling is that much of the content in this area was not sufficiently defined.  Also, the use of the original body structure does not take into account that the transplanted structure is not always in the same location as the original structure.

Only by testing the removal of the DIRECT SUBSTANCE would we see whether there was any substantial impact on classification.

Decision:

In general, agreement that the modeling was an  improvement.  Additional testing on the removal of the DIRECT SUBSTANCE will be undertaken.

• Jim Case to request view access to the TS browser for the EAG members to allow them to look at the remodeling impacts.
• Nicola Ingram to provide a list of "lost" subtypes from transplantation along with a designation of inactivation or moved.

Victor Medina 

Jim Case 

At the March 2024 EAG call, the group asked for an impact analysis of the change from Surgical approach to a more general Procedure approach.  The results of that analysis were presented at the April 2024 meeting.  At the April face-to-face meeting a list of non-surgical procedures that might benefit from this change was requested and is attached (download to view as spreadsheet).  

Discussion:

Comment from Matt Cordell 

Change Surgical approach to Procedure approach – I continue to support this. Good improvement.

Decision:

2024-04-16: Request to distribute list of non-surgical procedures affected by this change

2024-08-19: Postponed

2024-09-23:  General agreement that this is an improvement and that SI should move forward with the change.  EAG will be given access to the TS project prior to promotion.

• Victor Medina to distribute a list of non-surgical procedures affected by the proposed change

Feikje Hielkema-Raadsveld Daniel Karlsson 

At the November 2023 EAG call, a proposal to update the Physical object MRCM to allow for the modeling of containers was presented.  The EAG requested additional information as well as examples of the proposed modeling.  Feikje Hielkema-Raadsveld and Daniel Karlsson were provided with access to the SNOMED authoring platform to test their proposed model.  Questions that arose from this testing include:

• Should we group the attributes? We immediately ran into a problem grouping them. The MS discourages grouping attributes with the same type, but to create different role groups for each additive is very counter-intuitive. Are there other branches in SNOMED where this issue emerged, and what solution was adopted there?
• We propose a modification to our initial proposal: intended content should be specimen, not substance, to accommodate for instance container for 24 hour urine specimen
• Should we distinguish between blood collection tube and blood transfer tube? Why (not)? Our example project is working on the assumption that we drop that distinction.
• Should we distinguish between blood tube and blood container? If so, is the relevant distinction the shape or something else?
• We can model coagulation factors but not (yet) clot activators. We have left those concepts primitive, but we could model them by adding a disposition. Preferably one that can be grouped with coagulation factors. Is that worth doing? Those clot activators do pop up in every blood container branch.
• Do we want to want an attribute to dinstinguish between evacuated and non-evacuated containers, or do we keep those concepts primitive?

Discussion:

Comment from Matt Cordell 

Container modelling – “intended content should be specimen”, substance seems more accurate. If becomes a “specimen” in the container.
Consider the various blood collections – they all get whole blood put in them. but the tubes (with additives) produce different specimens, plasma, serum, whole blood, pack cells, buffy coat etc.
(Maybe there is a different attribute for input content, and contained substance?)

General comments:

Discussion on the use of substance vs. specimen.  The purpose of the model is to create models for pre-manufactured specimen specific containers.

The reason for the project is to address the need from some members to create a hierarchy of specimen containers to support European data projects and to allow for subsumption testing.  An issue that it would resolve is to allow specification of a container based on its characteristics in a FHIR model.  There are currently about 100 concepts that would be affected by this model.  This would allow for a cleanup of the container hierarchy as well.  Many of the concepts will require renaming or replacement.

What is the difference between a collection tube and a transfer tube?  May need to go back to GMDN to get definitions.  Their definitions may not be consistent with SNOMED.

Need more information on clot activators.  How to represent.  

Evalcuated or non-evacuated containers.  Jim Case  stated this is an intrinsic characteristic of the container and should  be represented.

Concern expressed about the complexity of the model and its relationship to other attributes  that are already defined for devices.  Specific editorial guidance will be necessary to allow for proper and consistent use of a physical object concept model that needs to represent such a wide variety of objects.

Decision:

Further discussion will be held at future meetings.

Jim Case 

Current and prior editorial policy for modeling of Events (<<272379006 |Event (event)|) stated that while the allowed attributes for events closely aligned with the Clinical finding concept model, editorial policy for using these attributes to model events were still under development.  However, one restriction has been applied and that is: "The Event hierarchy should not precoordinate periods of life/occurrence within the event concept."  It has been brought to our attention that there are a number of event concepts that do reference periods of life in which the event occurred.  Examples:

• 418189009 |Child abuse (event)|
• 242571000 |Accident due to neglect of child (event)|
• 12399091000119108 |Adult abuse (event)|
• 70055007 |Unexpected sudden death of adult (event)|
• 160957000 |Sudden infant death (event)|

A few of these have been modeled using the OCCURRENCE attribute in spite of the editorial guidance.  A member request has asked that we look at this policy as modeling of other concepts is being affected due to this restriction on modeling of events.  

Q: As  the OCCURRENCE attribute is currently an allowed attribute for EVENTS, should there be any restrictions on the use of these attributes.  If they should not be used, should the MRCM be modified to remove them from the allowed attributes set?

Discussion:

Comment from Matt Cordell 

• Age-related events modeling - I’m OK with keeping occurrence for these. I think simply having “Abuse” or “Death” (for the examples loses much of the meaning). I know there’s implications the “periods of life/occurrence” range brings, but perhaps we need to accept this is the language people use.

Decision:

2024-09-23: Postponed to later meeting

Victor Medina 

Jim Case 

As requested from the EAG, a list of definitions has been developed that will guide content authors in the correct modeling of concepts related to bypass, bypass graft, shunt, etc.:

Proposal for definition of concepts under 48537004 |Bypass graft (procedure)|.
Proposal for Definitions.

• CONSTRUCTION OF BYPASS. Surgical creation of a passage to carry contents
  around a part of a structure in its normal route and back to a structure in its
  normal route.
• CONSTRUCTION OF BYPASS USING GRAFT. Surgical creation of a passage, using a
  biological or synthetic material, to carry contents around a part of a structure in its
  normal route and back to a structure in its normal route.
• CONSTRUCTION OF SHUNT. Surgical creation of a passage allowing contents to
  move from one structure to another, not following its normal route.
• CONSTRUCTION OF SHUNT USING GRAFT (SYN: INTERPOSITION SHUNT). Surgical
  creation of a passage using a biological or synthetic material, allowing contents to
  move from one structure to another, not following its normal route.
• INTERPOSITION GRAFT. A surgical repair, using a biological or synthetic graft, of a
  structural defect that does not allow tension-free anastomosis.
• ANASTOMOSIS. Surgical procedure to create a cross-connection between
  channels, tubes, fibers, or other parts of a network.

Discussion:

Decision:

2024-03-11 Comments will be added to the document by the EAG members. 

2024-04-16: Proposed definitions will be revised based on input and resubmitted to the EAG for review.  

2024-08-19: Postponed

2024-09-23: Postponed to later meeting

• Victor Medina to revise definitions based on input from the EAG

Jim Case 

September 23, 2024