Background and purpose The incidence of electric scooter (e-scooter) injuries has increased drastically in numerous countries after widespread availability of shared e-scooters. The economic impact on society from a broader perspective has not been studied. We aimed to estimate the incidence of e-scooter injuries, describe the injury patterns, and estimate the costs of e-scooter injuries. Patients and methods: We performed a retrospective cohort study including all e-scooter-related injuries presented in the three adult emergency departments in Helsinki in 2021. We collected the patient data from the university hospital information system. Injury severity was evaluated based on the Abbreviated Injury Score. The cost of the hospital treatment was analyzed based on our hospital district’s service price listing. In addition, we recorded the total amount of sick leave days and estimated their economic impact. Results In total, 446 e-scooter injuries were identified and taken into the analysis (434 affecting riders and 12 non-riders). The median age of the patients was 26 (IQR 22–33), and 59% were male. 257 (58%) of the of the injuries were minor, whereas 155 (35%) were moderate, 30 (7%) serious, 3 (0.7%) severe, and one (0.2%) critical. Furthermore, 220 (49%) of the patients sustained head injuries. A major spike in accident incidence was seen during the weekend (Friday to Sunday) nights, accompanied by a proportional increase in patients with alcohol intoxication. Including both the costs of the hospital care and absence from work, the approximated total cost of e-scooter injuries was 1.7 million euros, with a median cost of a single accident being 1148 euros (IQR 399–4263 €). Interpretation: Considerable number of the injuries are moderate, severe, or worse. Comprehensive preventive measures must be conducted to decrease the incidence of e-scooter injuries. The use of helmets should be strongly encouraged to prevent severe head injuries. The nighttime bans during weekends and speed limits on e-scooters appear to be justifiable.

Background and purpose: The incidence of electric scooter (e-scooter) injuries has increased drastically in numerous countries after widespread availability of shared e-scooters. Most publications on e-scooter injuries focus on a specific category of injuries. The economic impact on society from a broader perspective has not been studied. Patients and methods: We performed a retrospective cohort study including all e-scooter-related injuries presented in the three adult emergency departments in Helsinki in 2021. We collected the patient data from the university hospital information system. Injury severity was evaluated based on the abbreviated injury score. Cost of the hospital treatment was analyzed based on our hospital district's service price listing. In addition, we recorded the total amount of sick leave days and estimated their economic impact. Results: In total, 446 e-scooter injuries were identified and taken into the analysis (434 affecting riders and 12 non-riders). The median age of the patients was 26 (IQR 22-33) and 59 % were male. 257 (58 %) of the of the injuries were minor, whereas 155 (35 %) were moderate, 30 (7 %) serious, 3 (0.7 %) severe, and one (0.2 %) critical. Furthermore, 220 (49 %) of the patients sustained head injuries. A major spike in accident incidence was seen during weekend (Friday to Sunday) nights, which was accompanied by a proportional increase in patients with alcohol intoxication. Including both the costs of the hospital care and absence from work, the approximated total cost of e-scooter injuries was 1.7 million euros, with a median cost of a single accident being 1148 euros (IQR 399-4263). Interpretation: Comprehensive preventive measures must be conducted to decrease the incidence of e-scooter injuries. The usage of helmets should be strongly encouraged in order to prevent severe head injuries. The night-time bans during weekends and speed-limits on e-scooters appear to be justifiable.

Objective: To investigate the effectiveness of restrictions on top speed and nighttime usage on the incidence of e-scooter-related injuries. Design: A retrospective comparative study. We compared shared e-scooter injuries from two periods: Unrestricted period (1.1-31.8.2021), and Restricted period (1.1.-31.8.2022). Setting: General population of Helsinki, Finland. We collected the data from the electric patient database from three trauma hospitals representing all public hospitals treating acute trauma patients in Helsinki. Participants: All patients with an injury related to shared e-scooter riding sustained in Helsinki Interventions: The restrictions established for shared e-scooters during the restricted period were: 1) The daytime top speed of 20km/h, as opposed to the previous 25km/h, 2) the use of shared e-scooters was prohibited on Friday and Saturday nights between 12 p.m. and 5 a.m, and 3) the nighttime top speed was lowered to 15 km/h from Sunday to Thursday between 12 p.m. and 5 a.m., as opposed to 25 km/h. Main outcome measure: Proportional incidence of e-scooter injuries compared to the total trips made by e-scooters. Results: There were 528 e-scooter injuries requiring hospital care during the unrestricted period (1.1.-31.8.2021) and 318 injuries during the restricted period of similar length (1.1.-31.8.2022). The proportional incidence of e-scooter injuries was 19 (95% CI 17-20) for every 100 000 rides during the unrestricted period and 9 (95% 8-10) per 100 000 rides during the restricted period. In the risk analysis, the odds ratio (OR) for shared e-scooter accidents was 0.5 (95% CI 0.4-0.6) for the restricted period when adjusted for hourly temperature, rain amount, wind speed, and visibility. After introducing the restrictions, the number of e-scooter injuries decreased significantly between 11 p.m. and 5 a.m. Conclusions: Restrictions on the top speed and nighttime usage of e-scooters decreased the amount of e-scooter injuries. We recommend similar restrictions in cities with shared e-scooter services.