A briefing note related to the use of the word “drug” in SNOMED concepts is linked below. We would like input from the EAG prior to circulating it for broader consultation.. Please provide comments here on the forum.
https://drive.google.com/file/d/1BgkAL-_j0pk9wc_O48yuK0djCSNJd-KC/view?usp=sharing
This opens a can of worms that is akin to the digit versus finger discussion.
• Does guidance need to be added to the Editorial Guide to discourage or restrict the use of drug?
Yes, because it will help to address ambiguity at the grouping concept level. Once a specific substance is named then any number of classification systems may apply to appropriately categorize or classify that substance based on the use case. (e.g. ATC, DEA schedules, FDA Drug Categories, GoodRx Drug Class, MedRT, etc.)
• When new concepts are requested with the term drug, how are these to be authored?
The context of the request will need to be taken into consideration. In the U.S. if “drug” is part of a named program for reimbursement, education, Assessment Scale, or other purpose then it will need to be allowed and retained as part of the FSN. For Example: 671231000124104 |Enrolled in Medicare drug plan (finding)| or 273426006 |Drug abuse screening test (assessment scale)|
We also need to take into consideration how LOINC and NPU content should be addressed in the observable entity hierarchy for things like 1031411000124100 |Drug Abuse Screening Test 28-item version (assessment scale)| so that that the content is consistently represented across the laboratory space.
• Does guidance vary according to hierarchy?
Can we refine the BN to be more explicit about what is in scope versus out of scope otherwise people like me will spiral down a rabbit hole and get focused on content that doesn’t matter. That being said, I think the SNOMED CT model components need to be addressed first. If “Drug” is considered ambiguous, then we should reduce to the ambiguity in the modeling components as an aid to the authors.
Hierarchy Impact assessment:
Looking across the various content, I think we need to provide a mix of editorial guidance. For any hierarchy where “drug” is used as a named item then it is allowed. For any hierarchy where it is not used as part of a named object provide more specific editorial guidance.
• Does guidance vary according to intention?
* There has been a general move away from identifying concepts based on therapeutic, diagnostic, recreational, illicit, medicinal, etc., use
I am not an expert in this area, but my gut reaction is that the guidance should be intention agnostic. The classification system applied to the substances may aid in the definition of intention. For example, a refset for diagnostic substances may be more useful then attempting to define it as part of the terminology to have it used for classification purposes.d
•How does potential guidance vary regarding FSN, PT, and SYN?
• Should other term(s) be used to describe drug instead?
• What to do with new content requests that contain drug?
• What to do with current content that contains drug? (800+ in Clinical findings)
Again, just brainstorming here but I think we can apply decisions made for existing editorial guidance to this situation for consistency. Given the ambiguity surrounding the word “drug”, it should not be allowed for use in the FSN but could be allowed in the PT or at the very least a SYN. (e.g. Bilateral versus both)
I think the best path forward is going to be refine the decision on editorial guidance across the hierarchies and then come up with an appropriate implementation plan to make the changes, in stages, across the hierarchies.
• Should the definition at 410942007 |Drug or medicament (substance)| be amended to include diagnostic substances?
• France (at least) defines drug as any substance not only to treat medical conditions, but also to diagnose them.
I think we may need to, otherwise we risk duplication and incorrect classification of substances like Arginine, Adenosine, Dobutamine, Edophonium, etc. substances. What defines a substance as diagnostic versus therapeutic appears to be the context under which it is administered. Identifying substance categories based on context of administration seems to be more appropriately handled as a refset, but that may not be feasible given the overhead to create and maintain the refsets over time.
• Should extracts of plants, <<289941004 |Plant extract (substance)|, be classified as 410942007 |Drug or medicament (substance)|?
• Many products that use extract substance as the active ingredient are modeled as <763158003 |Medicinal product (product)|. See <<1157193008 |Product containing plant material (product)|
This starts to go down a rabbit hole because tinctures specifically use alcohol as the solvent whereas extracts may use alcohol, water, vinegar, glycerin, oil , etc. as the solvent. Extracts may require the application heat during the extraction process where tinctures typically do not. Extracts and tinctures may or may not be standardized to a certain percentage of active ingredient by volume. Extracts and tinctures may also be specific to certain part of the plant (e.g. rhizome, bark, leaf, flower, etc.)
Depending on how far down this particular rabbit hole we want to descend, my preference would be to apply a modified version of the SEP from the body structure hierarchy to the organism or substance hierarchy so that the parts of a plant may be appropriately represented for use as ingredients. Plant extract substance concepts could then be inactivated and remodeled in the medicinal product hierarchy so that the solvent and any other applicable ingredients may be correctly modeled including the solvency ratio.
Additional comments:
• There will need to be some initial cleanup of content where a named substance appears in conjunction with the term “drug” as part of the FSN. For example: 580971000124101 |High dose opioid drug therapy (finding)|. This could be considered low hanging fruit and be cleaned up as part of an initial scope of work in which the word “drug” is removed from any FSN where a named substance is present.
These different meanings can occur in the same hierarchy. Therefore I would recommend guidance based on intention and not on hierarchy.
Some years ago, the substance grouper ‘allergen’ was retired; I think because being allergenic is not an inherent property of a substance. The same argument could probably be made for drugs and/or medication?
I do not want to argue for retiring 410942007 |Drug or medicament (substance)| - that would wreak havoc all over SNOMED. I just think we won’t get that modelling ‘right’ by looking at the inherent properties of these substances, because nature of more complex in this instance than the MRCM can handle.
Is “Drug” Really the Problem, or Is It How We Model It?
The term “drug” can mean different things depending on the context. For example:
Because the word drug has different meanings in medicine, everyday language, and legal contexts, it can create confusion in both SNOMED CT content and clinical communication.
Many people immediately associate the word with illegal substances or addiction.
Rather than focusing only on the word itself, we should consider whether clearer modelling using attributes and roles could better represent the intended meaning.
1. Should guidance be added to the Editorial Guide regarding the use of “drug”?
Yes. Guidance may ensure authors to avoid ambiguous use of the term drug and ensure the intended meaning is clear.
a. How should new concepts containing “drug” be authored?
When a request includes the word drug, authors should first clarify what is meant:
Clear guidance would help ensure consistent modelling and terminology.
b. Should guidance vary by hierarchy?
Yes. Some hierarchies, such as the Clinical Drug hierarchy, have an established purpose and structure that should remain unchanged.
Other hierarchies should use more precise terminology and avoid unnecessary ambiguity.
c. Should guidance vary according to intended use?
Yes. The same substance can have different uses depending on context.
For example, ketamine may be used as anaesthetic medicine, off-label use for pain management, and recreational or illicit use.
Rather than creating separate substance concepts, SNOMED may model the substance once and use relationships or attributes to represent its role or intended use.
Possible roles could include Therapeutic, Diagnostic, Substance of abuse etc
This aligns with the broader trend in SNOMED to avoid defining concepts primarily by their use (therapeutic, diagnostic, recreational, illicit, etc.).
d. Should guidance differ for FSN, PT, and Synonyms?
Any such guidance would need careful consideration for translation and international use.
2. Should another term replace “drug”?
No universal replacement. I think replacing one ambiguous term with another may not solve the problem.
SNOMED CT already contains more precise concepts such as Substance, Medicinal product.
I think the focus should be on using the correct concept and modelling approach rather than finding a single replacement word.
3. How should new content requests containing “drug” be handled?
Authors may need additional information about the intended meaning.
A mandatory selection of intended use such as Therapeutic, Diagnostic, Recreational, Substance of abuse etc; A required comment field providing context may improve consistency and reduce ambiguity during authoring.
4. What should be done with existing content containing “drug”?
There are already 800+ of concepts containing the term drug, particularly in the Clinical Finding hierarchy.
A phased review of high/medium/low-impact concepts which minimizes disruption while gradually improving consistency.
5. Should the definition of Drug or medicament (substance) include diagnostic substances?
Possibly.
As mentioned in earlier comments, some countries, define a drug as a substance used for diagnosis as well as treatment. However, definitions and regulatory frameworks vary internationally. Any change would need to consider global requirements and consistency across member countries.
6. Should plant extracts be classified as Drug or medicament (substance)?
No. Plant extracts may remain classified under Substance rather than automatically being classified as Drug or medicament (substance).
While many medicinal products contain plant-derived active ingredients, the extract itself is not necessarily a drug. The medicinal use should be represented at the product level rather than by reclassifying all plant extracts as drugs or Drug or medicament (substance). This will maintain clear separation between the substance itself and its potential uses in medicinal products.