Nontraumatic vs. Spontaneous injury

From Monique van Berkum 

Perhaps this has already been decided? I haven’t thought about it enough to know whether I agree, but the Editorial guidance below seems to imply that “Spontaneous injury” is distinct from |Non-traumatic injury|. 789750003 |Spontaneous event (event)| was added to SNOMED in 2020 and is used with DUE To 112 times in the stated view. Not all uses are for concepts that descend from |Non-traumatic injury|.

Even if these terms are used in clinical practice, I don’t think that most clinicians would appreciate the distinction between non-traumatic and spontaneous based the latter not having premonitory signs or symptoms. The guidance below implies that “Spontaneous injury” means injury with no underlying mechanism. If this distinction is maintained for injuries going forward, the difference between “Spontaneous injury” and |Non-traumatic injury| would need to be more clearly articulated.

From Feikje Hielkema-Raadsveld 

I have had a look through our translations and translation guidelines. For the most part, we have translated these terms literally, copying the English inconsistency and occasionally introducing some more inconsistency ourselves - as one does.

Spontaneous appears to be a negative concept, that you use when there is no external cause.  In non-injury concepts, this excludes for instance infectious causes; in injury concepts, it is less clear what such causes might be. If there are no other identifiable causes for an injury other than a trauma the distinction between spontaneous and non-traumatic is moot and in those cases the terms are used interchangeably.

The Netherlands has an explicit guideline that says to translate spontaneous haemorrhage or non-traumatic haemorrhage both as PTN niet-traumatische hemorragie SYN spontane bloeding. I.e. the guideline specifically recommends non-traumatic haemorrhage and sponteneous haemorrhage as synonymous.

Non-traumatic rupture has usually been translated in the same manner: PTN niet-traumatisch, SYN spontaan. However, when searching through SNOMED's concepts concerning spontaneous rupture, I believe I saw some exceptions in cases where an iatrogenic event is another likely cause:

• Prolonged spontaneous rupture of membranes - The other usual cause for ruptured membranes is iatrogenic and deliberate, I would hope a traumatic cause is quite rare; to distinguish between non-traumatic and traumatic would be quite confusing with respect to ruptured membranes.

• Spontaneous rupture of esophagus (Boerhaave syndrom) https://www.ncbi.nlm.nih.gov/books/NBK430808/ Boerhaave syndrome is usually not truly spontaneous, but this term helps distinguish it from iatrogenic perforation. Vomiting is the most common cause, but any activity that increases intraesophageal pressure can result in this syndrome. 

An injury with iatrogenic cause is certainly not spontaneous. But I am not sure: does iatrogenic count as traumatic, or as non-traumatic? Or neither?

All this I'm afraid is not particularly helpful in resolving on a course of action. I think there are many concepts, e.g. the haemorrhages, where spontaneous injury comes down to the same thing as non-traumatic injury and thus would make a proper synonym. But those are exceptions to the more general rule that a spontaneous disorder is more specific than a non-traumatic disorder; I fear we would have to identify the exceptions by examining them case by case. On the bright side, only 41 descendants of < 1119219007 |Nontraumatic injury (disorder)| have 'spontaneous' in a description. To answer Jim's original questions: 

1) should SNOMED explicitly separate out concepts where spontaneous injury is expressed as a synonym for nontraumatic 

Only if there is a usecase for that spontaneous injury as a separate concept. Please leave those haemorrhages as they are.

and 2) should SNOMED create nontraumatic injury concepts as parents to spontaneous injuries where a nontraumatic parent does not currently exist?

If it is a concept where spontaneous is in effect synonymous with non-traumatic, you would be better off changing the FSN or replacing it. Concepts such as 1088181000119100 |Spontaneous rupture of tympanic membrane of left ear co-occurrent and due to recurrent acute suppurative otitis media (disorder)| do refer to the more specific spontaneous and non-traumatic would I think just confuse. I have not managed to find a concept where an additional non-traumatic variant would be helpful.

From Jeff Pierson

Great discussion.  Attached is an analysis, which may or may not be helpful. 

Jim, I agree with Monique that having clear definitions should help us to determine if there is synonymy and how to move forward.

Also, all things being equal, I think “nontraumatic” is better as an FSN because “spontaneous” is harder to pin down.

Jim Case - has there been a final decision on this yet?

Jim Case Is this something we could/should discuss again at the next EAG? Or has a different follow-up action been planned?

In looking again at the subtle differences between "nontraumatic" and "spontaneous", the consistent distinction that is mentioned is that spontaneous injuries occur unexpectedly, without any external forces, and without any premonitory signs (this was mentioned in the first comments of this thread), while nontraumatic injuries occur without external forces but may or may not have premonitory signs.  Thus "nontraumatic" injuries are a supertype of spontaneous injury.  

The clinical usefulness of this distinction is related to any further evaluation of a patient after the injury occurs.  In spontaneous injuries, this may result in additional testing to try and identify any unknown underlying cause for the event.  In nontraumatic injuries with premonitory signs, preventive recommendations can be made to address future injuries of the same type.  

If the consensus is that this distinction is useful enough to maintain, nontraumatic and spontaneous descriptions should not appear on the same concept.  It also suggests that for injuries, where a spontaneous concept exists, a nontraumatic parent concept should also be present, but not vice versa.  This, however, does not hold true in non-injury concepts that are spontaneous, (e.g. miscarriage).  

There are 199 concepts that use the DUE TO = Spontaneous event relationship, of which only 75 are subtypes of nontraumatic injury.  Spreadsheet showing  the 301 subtypes of 1119219007 |Nontraumatic injury (disorder)| , which also shows which concepts have both nontraumatic and spontaneous descriptions in included (download to review).  A review of these concepts raises a number of questions regarding what qualifies a disorder to be assigned the primitive parent 1119219007 |Nontraumatic injury (disorder)|.