Bike helmets prevent pediatric head injury in serious bicycle crashes with motor vehicles

BACKGROUND: Approximately 75% of all bicycle-related mortality is secondary to head injuries, 85% of which could have been prevented by wearing a bicycle helmet. Younger children appear to be at greater risk than adults, yet helmet use is low despite this risk and legislation and ordinances requiring helmet use among younger riders. We sought to determine whether bicycle helmets are associated with the incidence and severity of head injury among pediatric bicyclists involved in a bicycle crash involving a motor vehicle. METHODS: We performed a retrospective review of patients age ≤ 18 years hospitalized at a level I pediatric trauma center between January 1, 2008, and December 31, 2018. Data were abstracted from the institutional trauma registry and electronic medical record. International Classification of Diseases 9th and 10th editions and external causes of injury codes were used to identify MV related bicycle crashes and determine the abbreviated injury severity (AIS) for head injury severity. Injury narratives were reviewed to determine helmet use. We calculated the incidence of head injury from bicycle vs. MV crashes utilizing descriptive statistics. We analyzed the risk and severity of injury utilizing univariate and multivariate logistic regression. RESULTS: Overall, 226 bicyclists were treated for injuries from being struck by a MV. The median age was 11 (interquartile range (IQR): 8 to 13) years. Helmeted bicyclists (n = 26, 27%) were younger (9.4 years versus 10.8 years, p = 0.04), and were less likely (OR 0.21, 95% CI 0.09 to 0.49) to be diagnosed with a head injury compared to unhelmeted bicyclists (n = 199). Of those with a head injury, helmeted bicyclists were less likely (OR 0.57, 95% CI 0.11–2.82) to sustain severe or higher injury using AIS. When adjusting for demographics (age, sex, race) and injury severity, helmet use predicted a reduction in head injury (OR 6.02, 95% CI 2.4–15.2). CONCLUSIONS: Bicycle helmet use was associated with reduced odds of head injury and severity of injury.. These results support the use of strategies to increase the uptake of bicycle helmets wearing as part of a comprehensive youth bicycling injury prevention program.