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Zoom Meeting Details
Topic: SNOMED Editorial Advisory Group
Time: Sep 26, 2022 05:30 Pacific Time (US and Canada)
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Meeting ID: 885 3132 6943
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Monica Harry Timothy Williams Yongsheng Gao Maria Braithwaite Jieun Hwang @peter jordan Frank Geier Andrew Marchant STEFAN SCHULZ Anna Rossander Peter G. Williams Andrew Perry Sarah Warren Ramamurthi Janakara Venkata François Macary Jeff Pierson Julie M. James Ana Paredes Olivier Bodenreider Kin-Wah Fung
The call recording is located here.
- Obtain consensus on agenda items
|Call to order and role call
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Conflicts of interest and agenda review
|Welcome new members
|Reevaluating "History" vs. "Past history" situation concepts
Currently, most "417662000 |History of clinical finding in subject (situation)|" concepts (~1000) are modeled with a TEMPORAL CONTEXT of 410513005 |In the past (qualifier value)|. The exceptions are "Family history of X" concepts. While this makes sense in the context of procedures, it is not so clear with clinical findings. In many cases clinical history involves conditions that are both current and in the past (e.g. history of cough for last 10 days). While we have a few concepts that specifically state "Past history", for the most part History of clinical findings represent conditions that were in the past and do not represent ongoing clinical conditions.
It is recommended that these concepts be remodeled with a new TEMPORAL CONTEXT, either the existing 410511007 |Current or past (actual) (qualifier value)|, or a new "Current and/or past (qualifier value). As this change is more general than the current modeling, it should have no impact on the taxonomic structure of the hierarchy.
In the past was modeled a long time ago and there was an argument that this was sufficient to model these concepts. There are some conditions that need to be evaluated as to whether they only occur in the past. Might need to look at Family history as well. Loosening this context up would be an improvement. Suggested to ask Ed Cheetham for background. There may also be some duplication. There is still a valid use case for "in the past" and "Current and/or past". The problem list use case requires that the context be explicitly represented.
Do we need additional contexts that refer to resolved? The Situation model was intended to be a "mini-information model".
No opposition to starting with this proposal
|The need for "duplicate" findings and disorders
We have examples of clinical findings and disorders that have identical modeling, and in some cases have identical descriptions. An example brought to our attention is that of "Inflamed joint" vs. "Arthritis". These are modeled identically and 3723001 |Arthritis (disorder)| has the additional description of "Joint inflammation". During internal discussions it was commented that there is a need to distinguish between observations made during clinical exam and those that represent a "diagnosis". Other examples include 281795003 |Inflamed tonsils (finding)| vs. 90176007 |Tonsillitis (disorder)|; 298170003 |Knee joint inflamed (finding)| vs. 371081002 |Arthritis of knee (disorder)|, etc.
Some proposed use cases were nursing findings, and the "need" to differentiate a finding on observation vs. diagnosis. We have recently completed inactivation of a large number of O/E (on examination) findings. However, we do not have a comprehensive representation of this pairing of findings and disorders in SNOMED CT. This impacts where specific descriptions may be applied; for example, we would not put the description "Inflammation of knee joint" on the concept 371081002 |Arthritis of knee (disorder)| (which is currently the case), since it would be more appropriate for 298170003 |Knee joint inflamed (finding)|. There is considerable inconsistency in the current content, for example there is 298171004 |Ankle joint inflamed (finding)|, but no "Arthritis of ankle".
Q: Is there a need to maintain this distinction and, if so, where should it be applied?
This is a discussion that has gone on for over 20 years, the finding/disorder dichotomy. The nursing use case (i.e. clinical observation) makes these findings vs. disorders which are diagnoses. The distinction is vague and inconsistent. We do not have a comprehensive representation of finding and disorder for many of these.
The distinction of who can make what type of finding/disorder should not be the responsibility of SNOMED. How far do we need to go to maintain the distinction? Arthritis seems like more of a definitive diagnosis as opposed to just a clinical finding. This is a problem with the use of and interpretation of the language. Because the terms are defined the same, what are the reasons for maintaining the difference? It is the context in which these concepts are used that makes the difference.
Intractable problem? The clinical interpretation is an important aspect that is not captured by the current concept model. There is an implicit notion of temporality. Findings are made at a point in time, whereas a "disorder/disease" requires more data. How do we keep the two "meanings" different?
Need to come back with a proposal to determine how many of these would be needed if the distinction is maintained. Also, for arthritis, what are the necessary conditions to make something a disorder? Can this be done?
|Modeling of "Palsy" concepts
From the meeting on 2022-08-24, a query had arisen internally regarding the definition and modeling of 784289008 |Nerve palsy (disorder)|. During the short discussion Jeremy Rogers had some very useful comments, copied below:
"I think the only truly defining characteristic of a “palsy” is the presence of partial or complete motor deficit. If its partial and unbalanced, it may manifest most obviously as tremor rather than paralysis.
So “palsy” is if anything synonymous with “hemiparesis (of any extent, including bilateral)” rather than with the motor or mixed neuropathy that is 99% of the time both co-occurrent and also the cause. This would also be consistent with the presumed etymology of the word “palsy” as being borrowed from the Greek παράλυσις (parálusis, “palsy”), from παραλύειν (paralúein, “to disable on one side”), from παρά (pará, “beside”) + λύειν (lúein, “loosen”).
The fact that there is often also sensory deficit too doesn’t IMHO make sensory deficit part of the palsy. Its merely a common co-occurrent but fundamentally different effect of the same underlying pathology: a mixed mononeuropathy. So all the texts that mention it aren’t saying that sensory deficit is a polythetic defining part of “palsy” but rather simply noting for the interested clinician that the two (rather than the one) commonly cooccur."
Based on this the updated modeling might include:
363714003 |Interprets (attribute)| : 52479005 |Motor function (observable entity)|
363713009 |Has interpretation (attribute)| : 260379002 |Impaired (qualifier value)|
A more difficult question is if a palsy is in effect one manifestation of the neuropathy, should these concepts be "findings" rather than disorders?
The current definition of palsy only uses peripheral nerves, also includes cranial nerves needed. Netherlands views palsy as a finding, whereas the disorder of the nerve affected is the disorder concept. We have many nerve disorders that may result in palsy, which is just a manifestation of the nerve disorder. We have a mix of palsy disorders and findings. Some can be explicitly linked with a specific nerve. In all cases, there is a loss of motor function, which needs to be represented in the model for the concept.
This is similar to the finding/disorder issue above. Weakness of X muscle vs. palsy of X muscle/body structure.
Seek information from the nascent Neurology group. Use Impaired for the HAS INTERPRETATION value based on the available definitions.
|Finding present (situation) vs. Finding present (finding)
A recent query from members brought to light the fact that SNOMED CT represents "Clinical finding present" concepts in two ways. The majority of the concepts (>550) are located in the Clinical finding hierarchy (e.g. 297990009 |Hair present (finding)|), with the majority of those concepts having a definition status of primitive. A small number (~55) are located in the Finding with explicit context hierarchy and are sufficiently defined, having been moved from the Clinical finding hierarchy, first to the "Context dependent category" (precursor to the Situation hierarchy) in 2004 and then to the Situation with explicit context hierarchy in 2006.
It may seem clear that the remaining "X present (finding)" concepts would logically belong in the Situation hierarchy; however, large changes in hierarchy have historically caused issues with implementations. Advice is sought concerning the potential move of these concepts.
Ancillary to this is the use or the TEMPORAL CONTEXT value 410512000 |Current or specified time (qualifier value)|. The addition of "specified time" is assumed to have been used to state that the referenced condition was known to be present based on a timestamp that is specified in the EHR, but has caused confusion for editors regarding the appropriate selection of "current" vs "current or specified time", leading to inconsistency in modeling of TEMPORAL CONTEXT..
An underlying assumption is made that the recording of the finding is contemporaneous with the the observation and that all modern EHR systems provide a timestamp for each recorded instance. If the observation is recorded at a future date, then a determination of whether the condition is still present (i.e. 15240007 |Current (qualifier value)|), or has resolved (i.e. 410513005 |In the past (qualifier value)|) must be made. This makes questionable the use of any temporal context value that refers to "specified time". The use of these temporal context values has been extremely limited, although subtypes (e.g. 410589000 |All times past (qualifier value)|) have been used for a relatively small number of concepts (<100).
Q: Given their limited use an questionable value, should Temporal context values that use "specified time" be inactivated and affected concepts be remodeled with the appropriate parent value?
Many of these cannot be expressed within the situation hierarchy because there is no way to represent the ASSOCIATED FINDING (e.g. testes present). Other terms that represent disorders can be moved over. Many of the existing finding concepts fall into the first category.
Should remove the description "Disease present" should be removed from "Disease". Determine whether there are approaches to make these sufficiently defined within the findings hierarchy.
Which is a better representation of currency, "Specified time" or "Current"? The use of Specified time explicitly states that the time associated with the finding is recorded elsewhere in the record. Issue with how to represent a specified time in the past.
For the issue around "Finding present" there may not be a need for temporal context at all.
SI will test some potential modeling patterns in the findings hierarchy to determine if we can sufficiently defined.
Will test whether leaving off temporal context when not stated has an impact on classification.
|Revisit movement of "At risk" concepts to Situation hierarchy
At the April 2022 EAG meeting, the EAG members, by consensus agreed to the inactivation and replacement of "At risk of X (finding)" concepts with Situation with explicit context concepts, making explicit the FINDING CONTEXT and re-terming to specify "increased" or "decreased" risk, as appropriate. SNOMED International has received a note from the Nursing CRG objecting to the proposed move. The document can be found at:
SNOMED has responded to the concerns in the attached document.
Question: Does this prior decision need to be revisited? It is proposed that a briefing note be distributed informing the MF, CMAG, and CoP of the proposed changes.
2022-09-26 Internal discussions indicated that there are concerns about breaking current implementations for these highly used concepts in the nursing domain. A request to look at alternative representation as a finding was evaluated. The use of HAS REALIZATION has been considered:
Situation model example:
Note: Suggested that adding subtypes of At risk context (e.g. At increased risk, At decreased risk, etc.) would allow for sufficient definition.
Finding model example:
Note: "Clinical findings" currently not in the range of HAS REALIZATION
Discussion with the CMAG and presentation of options resulted in a straw poll of 10-8 in favor of the Situation representation.
All members agreed that leaving them in the findings hierarchy. Potentially change the top level concept to represent either increased or decreased. (i.e. finding of risk status, top level grouper). Must avoid "relative risk" based on previous determination.
Test the findings model, update the nursing CRG.
Briefing note on inactivation of concepts including "delivered/not delivered"
Existing obstetric content that includes the statement "delivered/not delivered" will be inactivated as follows:
Inactivation reason: Classification derived concept
Both of these concepts must be used to replace 198905007 |Placenta previa with hemorrhage - delivered (disorder)|
Inactivation reason: Classification derived concept
Briefing note above gives additional detail
What is the need for the pointer to the "Mother delivered"? What about the antenatal/postnatal complication concepts? Does this mean "Not delivered"? The timing of these imbedded in the concept makes them ambiguous as to the temporal context.
Limit the changes to the - delivered/- not delivered and avoid the antenatal/postnatal terms. Also review the descriptions to make sure they do not include delivered/not delivered as synonyms.
Put out a doodle poll to determine a new time for the conference calls.