•  Recording of meeting approved by participants.

Conflicts of interest and agenda review

Inactivation of Navigational concept hierarchy

At risk concept modeling

update

In reference to content development in the International release, the following must be considered:

• On 2020-04-29 the EAG approved an editorial policy: When defining observable entities for the international release, the SCALE TYPE attribute will not be used. If extensions would like to add specific subtypes of observable entities that include the SCALE TYPE, they are free to do so.
  When using observable entities to define clinical findings, international concepts that do not include a SCALE TYPE relationship would be used a values for the INTERPRETS relationship. The exception to this guidance are existing "vital sign" observable entities that have been defined with the SCALE TYPE of "Quantitative".
• The majority of Observable entities in the International release of SNOMED CT are not modeled, so Scale Type is not available.
• There are currently no International concepts that require concrete values for HAS INTERPRETATION
• It is not possible to support both concept based values and concrete values in the same range for a scale type such as "Quantitative or Ordinal"

Discussion:

James R. Campbell described the use of risk calculators at UNMC.  One question that had arisen was the editorial decision to not include a value for the SCALE attribute to Observable entities in the international release.  This was due to the fact that the "expected" scale was adequately described by the PROPERTY attribute value, and the TECHNIQUE attribute value as well as the observation that many of these risk calculators allowed for either a Ordinal or quantitative value.

However, the Regenstrief/SNOMED agreement obviates much of this as the LOINC extension will necessarily contain SCALE TYPE as that is a required LOINC part in the definition of a LOINC term. 

A discussion ensued on the need to create clinical findings that represented the combined observable-value that is represented by the INTERPRETS/HAS INTERPRETATION relationship group.  This did not seem to be the way that the data are collected in the EHR.  However, it was recognized that there is a need for clinical findings to be used as members of a value set bound to an observable to support assessments. 

Decision:

The discussion ended with consensus that there is no compelling use case at this time to expand the range of HAS INTERPRETATION at this time. The need to revise the editorial policy related to the inclusion of SCALE TYPE in modeling observable entities in the International release will be re-evaluated by the SNOMED content team.

Should "Mechanical complication of device" be a disorder or a finding?

Current situation:

111746009 |Mechanical complication of device (disorder)| has 215 subtypes, all of which refer to a failure of a device without specifying a deleterious effect on the patient. 

       e.g. 285961000119107 |Mechanical breakdown of prosthetic heart valve (disorder)|

We also have disorder concepts that refer to a patient condition due to mechanical failure of a device 

       e.g. 5053004 |Cardiac insufficiency due to prosthesis (disorder)|

Without specifying the resultant condition associated with device mechanical issues, is it appropriate that these are represented as patient disorders, or should they be findings that may be related to disorders in the patient?

A briefing note using "Leakage of device as an example is located here.

Discussion:

Without an associated condition in the patient it is unclear whether there is an adverse impact on the patient.  In general, if the device is implanted, it can be assumed that there is a negative impact. These should be retained as disorders.  Each of the subtypes would need to be evaluated as to the potential impact on the patient.

2023-04-04

Additional issues and questions:

1. If we agree that implantable device malfunctions result in an adverse condition in the patient, should the FSN reflect that, e.g. "Disorder due to mechanical breakdown of prosthetic heart valve"? Consensus - no...
2. SNOMED CT does not have a general classification of implantable devices.  Is the following definition suitable to provide editorial guidance? FDA - "Medical implants are devices or tissues that are placed inside or on the surface of the body." Consensus - no

Definition provided by John Snyder - "Medically implanted devices refer to any manufactured device, prosthesis, or biological construct that is surgically implanted into or physically attached to the body to aid in the diagnosis, treatment, or monitoring of a medical condition".

Implantable devices might be considered as a type of body part, thus a disorder of the device would of necessity cause a problem in the patient and should be a disorder. While there may not be a morphological abnormality, there is an abnormality of the device. Is a new attribute needed to represent device abnormality?  This discussion is restricted to medical devices and not transplanted tissues and organs.

Some implantable devices are not prostheses.

With reference to a proposed definition, what does physically attached mean?  Look at how FHIR has addressed this.  Should imply some introduction method, rather than just an attachment to the body.

The top level concept could be moved to clinical findings.  There is an issue with the term "complication".  Subtypes would be individually reassessed.  Propose that the disorder boundary start with mechanical complication of implanted device.

Kin Wah will provide documents related to a discussion on implantable devices.

Update 2023-04-10:

Upon investigation, as expected, these concepts (i.e. Mechanical complication) are classification derived (ICD-9, ICD-10, and ICD-11) and refer to injury or harm to a patient caused by a failure, breakdown, or malfunction of a device.  Coding guidance indicated that (for ICD-11) the disorder caused by the mechanical complication should be coded first and then associated with the device. Thus, the intended meaning of these concepts imply a disorder in the patient due to some issue with the device. The actual terms are index terms in the ICD.  Example:

PK91.22 Cardiovascular devices associated with injury or harm, mechanical or bioprosthetic valves (ICD-11)

    Index term: Mechanical complication of heart valve prosthesis

This would suggest that these concepts are correctly placed in the taxonomy, and they are currently mapped to ICD disorders (i.e. injury or harm to patient) but are possibly not modeled sufficiently to express the implied meaning.  A new approach to modeling these concepts will be undertaken to clean up this sub-hierarchy.

Definition of device malfunction from the US Code of Federal Regulations TITLE 21--FOOD AND DRUGS, CHAPTER I--FOOD AND DRUG ADMINISTRATION, SUBCHAPTER H - MEDICAL DEVICES
PART 803 -- MEDICAL DEVICE REPORTING: "Malfunction means the failure of a device to meet its performance specifications or otherwise perform as intended. Performance specifications include all claims made in the labeling for the device. The intended performance of a device refers to the intended use for which the device is labeled or marketed..."

A query was posed as to the difference between 129433002 |Inspection - action (qualifier value)| and 281615006 |Exploration - action (qualifier value)|, both subtypes of 302199004 |Examination - action (qualifier value)|. The internal consensus was that these are clinically different with the former limited to visual evaluation and the latter implying an active examination.  Various medical dictionary definitions concur with this view:

e.g. Exploration - "An active examination, usually involving endoscopy or a surgical procedure, to ascertain conditions present as an aid in diagnosis. - 
Medical Dictionary for the Health Professions and Nursing © Farlex 2012"

Inspection - "The visual examination of the body using the eyes and a lighted instrument if needed. The sense of smell may also be used. - Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved."

This would imply that surgical procedures would more frequently use exploration as the METHOD than inspection; however, this does not appear to be the case

<<387713003 |Surgical procedure|:260686004 |Method| = 129433002 |Inspection - action| = 306

<<387713003 |Surgical procedure|:260686004 |Method| = 281615006 |Exploration - action| = 150

For non-surgical procedures the difference is more extreme

(<<71388002 |Procedure| MINUS <<387713003 |Surgical procedure|):260686004 |Method| = 129433002 |Inspection - action| = 710

(<<71388002 |Procedure| MINUS <<387713003 |Surgical procedure|):260686004 |Method| = 281615006 |Exploration - action| = 220

Many of the non-surgical procedures modeled using inspection are some form of endoscopy.  Given the definitions above and the consensus of the internal content development team, should SI undertake a project replacing Inspection with Exploration for surgical and endoscopic procedures?  It is anticipated that much of this can be done automatically.

Discussion:

Need to review the definition associated with Inspection procedure and Exploration procedure. General consensus is that we do not change the modeling unless there is a clear distinction that can be applied other than what is expressed in the FSN. 

Explorations can be performed without visualization, but Inspections do require visualization.  The current definitions on both need clarification as they imply a supertype/subtype relationship:

122458006 |Exploration procedure (procedure)| -  An observation of the body or a body part done by inspection and/or palpation.

32750006 |Inspection (procedure)| - An exploration using the sense of sight, done with the eyes.

Endoscopy/laparoscopy etc. all use a scope of some sort to visualize the body structures, so should use Inspection as the action. Almost all concepts that use Exploration - action have the word Exploration in the FSN. 

An associated question, based on the current definition in SNOMED of Exploratory procedure, should Palpation -action be a subtype of Exploration - action?  

The use of the SEVERITY attribute is complicated by the lack of knowledge about the ordinal scale from which the selected severity originated.  For example, the source severity value set may have different sets of values such as: 

• mild / moderate / severe
• minimal / mild / moderate / severe / very severe
• mild / mild to moderate / moderate / moderate to severe / severe / life threatening / fatal

The current editorial guidance for the use of the SEVERITY attribute has a modeling note attached:

The question is whether the restrictions on the use of SEVERITY in the International release be relaxed, allowing for any concept that explicitly states severity in the FSN have a severity relationship assigned?  

Discussion:

Decision:

In January, the EAG discussed the definition of "Surgical procedure" and revision of the current MRCM attribute was discussed (2023-01-23 SNOMED Editorial Advisory Group Conference Call).  In light of the fact that we are not able to come up with a standard definition for surgical procedure, we should eliminate the specific action methods under 129284003 |Surgical action (qualifier value)| to the more general 129264002 |Action (qualifier value)| concepts.  As we review the current 129264002 |Action (qualifier value)| hierarchy, we are finding that there are a number of actions that can be applied to either a surgical or non-surgical procedure.  

What we have found is that the definition of a surgical procedure depends primarily on who performs the procedure.  This is problematic as the same procedure may be performed by multiple categories of healthcare professionals. The current definition was broadened from the initial definition in 2021 and now represents an overarching meaning that overlaps with many types of procedures that would not normally be considered surgical (e.g. freezing of warts, reduction of nursemaid elbow). 

Retaining this distinction of surgical and non-surgical procedure will result in the need to create a number of specific surgical actions with unknown benefit in the classification of procedure concepts.  Elimination of the need to specify Surgical procedure as a specific subtype of procedure would obviate the need for the creation of these specific "surgical" actions.