The continuous increase of e-scooter associated injuries over the last years confirms the perceived growth in use and the corresponding risk of this new mobility trend. The high number of overall head injuries, concerning a quarter of all patients, demonstrates the importance of the evaluation of helmet use. With only 13.7% of drivers wearing helmets, this study confirms the low numbers reported in the current literature[26–28]. In this study, patients wearing helmets suffered half as many overall head injuries as patients who did not. Therefore, helmet usage's contribution to reducing head injuries can be assumed. The benefits of using helmets to prevent major head injuries, particularly TBIs reported in the literature, could not be demonstrated based on the available data, as TBI rates in both groups were nearly identical[29]. The higher rate of major facial skull injuries in patients wearing helmets could be due to different riding behavior in terms of a higher willingness to take risks. Zhou et al. confirm the preventive benefits of wearing helmets after tightening legal regulations for e-bike use[30]. Combined with the data found in this study, the lack of legal helmet requirements for e-scooter usage should be questioned. The considerable part of major injuries concerning the head, elbow, and hand found in this study show similarities with current literature, describing the before-mentioned anatomical regions as vulnerable in e-scooter associated accidents[31].
The hospitalization rate of patients suffering major injuries in our study was 24.5%, with 14% needing surgery. These findings are similar to those reported by Bekhit et al. (30.5% and 19.9%)[32].
The rising popularity of e-scooters and related growth in e-scooter associated injuries has raised concerns about possible increases of overall healthcare costs[33]. This confirms the importance and potential of practical preventive concepts to lower the burden on the overall healthcare system.
Demographic results of this study show patients being predominantly male, with a mean age well below 40 years. These are consistent with data reported in the current literature[34]. Gender discrepancy as well as age distribution could be due to a difference in fundamental e-scooter usage. Patients getting injured while driving e-scooters were more frequently male, had a significantly lower mean age, and suffered major injuries at a higher rate compared to the non-driving group, which could indicate possible differences in driving behavior. Laa et al. described the demographics of e-scooter users in Vienna, which show similarities to the demographic data reported in our study[35]. However, the influence of potential factors related to riding behavior, such as user characteristics or risk tolerance of riders, were not addressed in the present work and may serve as a base for further studies.
Reported collisions with vehicles, bicyclists, and pedestrians indicate a potential conflict with other traffic users. This may be due to the international grey area that e-scooter riders find themselves in regarding the use of sidewalks or roadways[36]. Traffic regulations in Austria regarding e-scooters are primarily adapted to bicycles, and therefore most e-scooter activity takes place on roads or multipurpose lanes. This may explain the relatively large proportion of confrontations with motor vehicles.
The use of e-scooters under the influence of alcohol is widely discussed in the literature, showing a low inhibition threshold for riding while impaired and still having a subjectively strong feeling of safety[37]. Uluk et al. demonstrated a correlation between severe head injuries and previous alcohol consumption[38]. Our study confirmed this with more than a fifth of the patients suffering any form of TBI getting injured under the influence of alcohol.
Accumulation of injury numbers over the summer months provides an indication of seasonality in e-scooter use. It confirms the basic assumption of greater willingness to engage in outdoor activities during warmer temperatures. Injury numbers distributed evenly over different weekdays confirm e-scooters as everyday transportation. Proportions of work and leisure accidents mentioned in our study demonstrate the use of e-scooters as an alternative form of transport to and from work. However, recreational journeys currently make up a clear majority.
The relatively moderate patient increase during 2020 might be related to the significant decrease in overall trauma cases during the Covid-19 pandemic[39]. Recommendations like reducing social contacts, quarantine regulations, and home office activities led to decreased traffic volume and, therefore, lower numbers of recorded accidents[40–42].
Although we did not evaluate the use of other protective equipment, current literature suggests that elbow pads or wrist guards can prevent other common injuries found in this study, such as proximal and distal radius fractures[43]. With both conservatively and operatively treated injuries often resulting in occupational limitations or complete inability to work, great importance should also be assigned to the primary prevention of accidents. Efforts to continuously revise traffic guidelines and establish new safety concepts can contribute to the further development of e-scooter acceptance[44].