Conflicts of interest

Notice of recording

EAG accepted proposal to eliminate the use of "Co-occurrent and Due to" pattern in favor of "Due to".

There are a large number of disorder concepts that refer to "Secondary" or "Secondary to". A query was sent to the WHO ICD MSAC (Medical and scientific advisory committee):

• It is unclear from the [ICD-11] definitions associated with the various conditions that use the term "secondary" as to whether it refers to simple co-occurrence or some level of causality, or both, as most of the definitions define secondary disorders as "disorder secondary to X" which is not very helpful.
• This is important from the SNOMED point of view as we are trying to separate out causality from simple temporal relationships. If by "secondary"; ICD actually means a "Complication X due to disease Y", then we would reconsider many of the terms we have that currently make a distinction between ""Complication" and "Secondary".

• There is also a question concerning the phrase ‘associated with’. As it is ambiguous, it is desirable that this phrase be deprecated.

Implications on modeling and terming of existing content as part of the QI project need to be discussed and recommendations provided to the content team.

Related SNOMED trackers:

Modeling of secondary diseases

artf6264-Complications - sequelae - secondary

Concept model for secondary disorders

artf6302-Review of Secondary X (disorder) concepts versus X associated with another disease

artf221501-metastatic malignant neoplasm

WHO ICD-11 guidance

2.3.5 ‘Due to’ and ‘With’

‘Due to’ is the preferred term for categories where two conditions are mentioned and a causal sequence exists. Other terms, such as ‘caused by’ or ‘attributed to’ are allowable synonyms. The phrase ‘secondary to’ is equivalent and may also be included as a synonym. 'Associated with’ is the preferred term for categories where two conditions are mentioned and there is no causal sequence implied.

There was also some work done in the Reference guide by the Morbidity Reference Group in partnership with Quality and Safety.

Coding from health care practitioner documentation of “causal relationships”

Sometimes conditions that have a causal relationship are clearly documented by the health care practitioner using terms such as “due to”, “caused by”, or “arising from”. These connecting terms indicate the health care practitioner has made a causal link between, for example, condition A due to condition B.  However, sometimes conditions are documented with connecting terms that are ambiguous for the coder such as “with”, “after”, “in”, and “following”.  When ambiguous terms are documented and it is not clear whether the health care practitioner means a causal inference or not, the clinical coder should code each condition separately and not link in a cluster.

The clustering (postcoordination) is a particularly notable new feature in ICD11 that has permitted the introduction of powerful new clinical coding mechanisms for capturing clinical information in dimensions such as:

• quality and safety coding for healthcare related injury and harms (see 3 part model described in section {YYY})
• the addition of clinical detail using extension codes
• the specification of diagnosis type and diagnosis timing using extension codes
• the comprehensive description of late effects (sequelae) arising from prior conditions (see section {ZZZ})
• the description of inter related stem code diagnoses where there is a clear causal relationship
  
  For more information on causal inference in the context of quality and safety, refer  to section {XXX (currently: 2.31.5.1 Causation in the context of quality and safety)}

From October 2018 MSAC Minutes:

• For entities where the aetiology is specifically known, and the combination of condition and aetiology exists as a fully precoordinated entity, “Due to” is the preferred term. Other terms, such as “caused by” or “attributed to” may be allowed synonyms. The phrase “secondary to” is equivalent and may also be included as a synonym. This proposed solution may only be used, however, when the causal link is clearly defined.
• Note, the phrases “secondary” and “secondary to” are not logically equivalent and may not be used interchangeably.
• In concepts where an association is known, yet not as a known or proven aetiological connection, and the condition and association combination exist as a fully precoordinated entity, “associated with” is the preferred term. The connections “with” and “in” are not allowed combinations.
• When considering neoplastic entities, the allowed term is “metastatic”, not “secondary”.

• There was agreement that ‘secondary’ implies causality, but there was not agreement as to what “associated with’ means.

Revisit the intended meaning and operational consequences of the nine subflavours of 900000000000522004|Historical association reference set (foundation metadata concept)|

• ‘historical associations’ are to be declared between inactive concepts and their candidate active (and so taxonomically reportable) substitute(s).
• Sections within the RefSets Practical and Terminology Services guide mention that such associations exist - though they’re rather silent on what you can or should do with them.
• No obviously visible guidance (e.g. in the new Editorial Guide) on how and why authors should decide what makes a ‘good association’
• Not a lot of understanding of the possible consequences of a bad or missing one.

Summary of discussion from F2F meeting

1. The distinction between Finding and Disease has been and is a cause of confusion for modelers and implementers.
2. The use of implied context for the Clinical findings/Disease hierarchy causes issues for implementers in that other context-types are located in a separate top-level hierarchy.
3. We are currently using the Clinical findings hierarchy as both “Clinical entities” and “Assertions”.
4. It is desirable to have a “pure” clinical entities hierarchy that can be used to populate assertions (clinical statements). Potential names proposed:
a. “Findables”
b. Phenomena
c. Clinical entity
5. A number of the attributes of the Clinical findings concept model are context-type relationships.
6. It was generally agreed that SNOMED should evolve to include a “context-less” set of defined clinical entities that would support the population of a more robust and comprehensive “clinical statement” model.
7. A review of the various extant (and useful) clinical statement models should be undertaken to inform the structure of a SNOMED CT clinical statement model.
8. The current Situation with explicit context model is viewed as a starting point for the development of the SNOMED Clinical statement model.
9. A clear statement regarding the removal of support for the “Soft context” for Clinical findings and Procedures must be communicated to the implementation community.
a. Removal references to soft context from the Editorial guide.
b. Recommended that clinical entities would not be used directly, but only as a component of a clinical statement.
10. Post-coordinated expressions have a number of issues related to construction, determination of equivalence and reusability that make them less appealing as a solution to context.
a. Most large EHR systems implementations do not support post-coordination.
11. The current Situation model simply provided a way to move concepts that were context-laden, out of the ostensibly context-free Clinical findings hierarchy.
12. Logical negation is out of scope.
a. Does not conform with non-binary representations of presence or absence.
13. Any solution should be developed in conjunction with information model developers.
14. We need to develop an incremental approach to this change as it may be viewed as to dramatic for some users.

Potential Actions

• Write a project charter. Should outline what the end goal of the project is and what the perceived benefits and potential detriments there might be. Name?
• Propose the creation of a formal project group (Clinical statement project?). The initial though is to create two types of groups, a small, formal work group and a larger project group. These would be modeled after the groups in the drugs project.
• Write the Terms of Reference for the Project Work Group and the overall Project Group
• Identify potential members. What is the proposed size of the group. The bigger the group, the more difficult it will be to get consensus. However, without adequate representation, the more chance we will have of getting pushback.
• Develop a draft strategy and the critical path for addressing the issues that we identify

a. Identification of the specific issues.
b. Predict the potential impact of the terminology
c. Outline that potential issues that might impact users and implementers
d. Develop mitigating strategies for minimizing impact.

• Notify the Community of practice about the project group and its objectives

a. Solicit feedback from the CoP. That will be our consultation process.
b. Change or revise the terms of reference as needed from input.

• Begin environmental scan for clinical statement models that can be used as starting points for comparison. Candidates include:

a. HL7 Clinical Statement model: (https://www.hl7.org/implement/standards/product_brief.cfm?product_id=40)
b. FHIR resources: (https://www.hl7.org/fhir/resourcelist.html)
c. CIMI?