JC: Are e-scooter injury patterns different and does it matter? St Emlyn’s

I was recently reviewing the traumatic brain injury audits of a local trauma service and was surprised to see that just over a third of patients were a result of e-scooter crashes. Whilst many people have views about e-scooters it was the data that really caught my eye. Personally, I’ve certainly attended a fair few incidents as a clinician, and I’ve dodged a few who’ve been riding on the pavement but I’ve also ridden a few myself and there is certainly an appeal to doing so. There are also a number of review articles and past papers suggesting a significant injury burden from these devices^​1​.

What about injury patterns though? As a lifelong cyclist I’m familiar with riding at speed on wheels, and how people fall from them when things go wrong, but scooters feel very different with a smaller footprint and a more erect riding position. It therefore follows that injury pattern might be different. Fortunately there is a paper that addresses this and does indeed suggest different injury patterns^​2​.

The abstract is below, but as always we strongly recommend you read the paper and come to your own conclusions.

What kind of paper is this?
This is a retrospective cohort study using data from the TARN registry. Retrospective cohort studies are always a bit tricky as they are reliant on good data entry at the time, and at a time when those inputting the data were unaware that this study was going to be completed. That said, this study uses an established database that has a long history of data systematic data collection. It’s therefore a more robust model than simply trawling through old notes in the hope that data was recorded at the time.

What/who did they look at?
This study looked to compare injury patterns between e-scooter riders and cyclists. That seems a reasonable comparison as I suspect that many journeys would be suitable for either mode of transport. However, I would imagine that recreational cyclists are more likely to take long journeys by bike, whereas e-scooters are more likely to be shorter distances.

Tell me about the patients.
The study sought all patients on the TARN database as a result of an e-scooter, or bicycle accident over a 1 year period in 2021. To get onto the TARN database there are strict criteria which preferentially selects out those with more severe injury.

What did they find?
The database delivered 2831 patients, of whom 293 were a result of e-scooter accidents.

E-scooter patients were more likely to be admitted to an MTC and/or critical care, and more often had a serious (AIS>2) head or limb injury. The difference in injury patterns were quite significant with head injury differeng by nearly 15% (35.2% vs. 19.7%) and for limb injury over a 12% difference (39.9% vs. 27.2%), both results were highly statistically significant.
Notably over a third of the patients were outside the current UK legislature as a result of intoxication (26%) and/or age (14%).

What do the results mean?
As clinicians the results do indeed suggest a slightly different pattern of injury as compared to bicycle riders. There are of course many potential reasons for this. The biomechanics of riding, and therefore of falling will be different, and as the data on alcohol intoxication suggests, they may be being used for different purposes. Anecdotally it seems that head protection is less common amongst scooter users, and that was also the case in this cohort, (but I don’t want to get into the bin fire of helmet debates here).

What this paper may do is push me to do more, and better targeted health promotion advice when reviewing patients with less severe injury in the ED and before discharge. That’s something I’ve done for years for other road (pavement) users and this ay allow that to be a little more bespoke. I’d rather do a brief intervention about rider safety (for all users) now than see them again soon with a more severe injury.

In this paper the authors argue for changes to legislation but that’s beyond the scope of this blog.

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