Concussion patients have an elevated risk of motor vehicle crashes after injury
By Zoe Marquis. This article was initially published in the 1/15/26 Edition of our Concussion Update newsletter; please consider subscribing.
A recent retrospective cohort analysis published in BMJ Open found that concussion patients have a 49% higher long-term risk of being in a serious motor vehicle crash after injury compared to patients with an ankle sprain. This concussion-related increase in risk of being in a serious motor vehicle crash is greater than the increase in risk associated with sleep apnoea or epilepsy. Additionally, in the first month after injury, the risk of motor vehicle crashes was over six times higher for concussion patients than for ankle sprain patients. The elevated risk was observed across diverse subgroups in the study population, persisted throughout the 20-year study window, and was exacerbated by repeated concussions and driving later at night. Researchers Donald Redelmeier et al. analyzed the records of 3,037,028 patients who received a diagnosis of either a concussion or an ankle sprain between 2002 and 2022. They tracked subsequent emergency room visits due to motor vehicle crashes for a median of 10 years after injury. The researchers suggest that their findings may warrant a safety warning from clinicians about the risk of motor vehicle crashes after a concussion and advice to minimize high-speed and late-night trips as much as possible, especially in the first month after injury.
Interlude from Concussion Alliance:
Motor vehicle accidents are a common cause of concussions, as well as moderate and severe TBIs. Moreover, patients who sustain multiple concussions in a short time are more likely to experience longer recoveries and persisting symptoms after concussion. Thus, the findings of this study are particularly important. According to this study, concussion patients had a 73% increase in traffic risk after a single concussion, a 114% increase after two concussions, and a 124% increase after three concussions. Combined with the findings that the risk of motor vehicle crash was highest in the first month after concussion (which is, notably, the period when sustaining an additional concussion is most dangerous), these results provide much-needed context for the risks of driving after a concussion.
In total, 200,603 patients were injured in motor vehicle crashes during the follow-up period of the study. Concussion patients had an average rate of 10.58 crashes per 1000 people annually, while ankle sprain patients had an average rate of 6.18 crashes per 1000 people annually. Patients with an ankle sprain were used as a control because they shared the same context as patients who sustained a concussion (experiencing an injury and contacting a physician), but were neurologically unaffected.
The researchers suggest that the elevated risk of motor vehicle crashes observed in concussion patients could be due to the neurological effects of concussion. They note that “past research suggests concussions can sometimes lead to neurological disabilities that could contribute to traffic risks.” However, this past research has limitations—such as small sample sizes, unrepresentative volunteers, and artificial circumstances (driving simulations rather than actual crashes). Indeed, the researchers caution that their study is correlational, and thus, they cannot conclude that concussions cause an elevated risk of motor vehicle crashes. Other limitations include the lack of data on who was at fault, distances driven, and concussion severity.
