BackgroundE-bike usage is increasingly popular and concerns about e-bike-related injuries and safety have risen as more injured e-bikers attend the emergency department (ED). Traumatic brain injury (TBI) is the main cause of severe morbidity and mortality in bicycle-related accidents. This study compares the frequency and severity of TBI after an accident with an e-bike or classic bicycle among patients treated in the ED.MethodsThis was a prospective cohort study of patients with bicycle-related injuries attending the ED of a level 1 trauma centre in the Netherlands between June 2016 and May 2017. The primary outcomes were frequency and severity of TBI (defined by the Abbreviated Injury Scale head score ≥1). Injury Severity Score, surgical intervention, hospitalisation and 30-day mortality were secondary outcomes. Independent risk factors for TBI were identified with multiple logistic regression.ResultsWe included 834 patients, of whom there were 379 e-bike and 455 classic bicycle users. The frequency of TBI was not significantly different between the e-bike and classic bicycle group (respectively, n=56, 15% vs n=73, 16%; p=0.61). After adjusting for age, gender, velocity, anticoagulation use and alcohol intoxication the OR for TBI with an e-bike compared with classic bicycle was 0.90 (95% CI 0.56 to 1.45). Independent of type of bicycle, TBI was more likely if velocity was 26–45 km/hour, OR 8.14 (95% CI 2.36 to 28.08), the patient was highly alcohol intoxicated, OR 7.02 (95% CI 2.88 to 17.08) or used anticoagulants, OR 2.18 (95% CI 1.20 to 3.97). TBI severity was similar in both groups (p=0.65): eight e-bike and seven classic bicycle accident victims had serious TBI.ConclusionThe frequency and severity of TBI among patients treated for bicycle-related injuries at our ED was similar for e-bike and classic bicycle users. Velocity, alcohol intoxication and anticoagulant use were the main determinants of the risk of head injury regardless of type of bicycle used.