Bicycle helmets are associated with fewer and less severe head injuries and fewer neurosurgical procedures.

Purpose: This study explores the protective capabilities of bicycle helmets on serious head injury among bicyclists hospitalized in a Norwegian level 1 trauma centre. Method: Information on helmet use, demographic variables, Abbreviated Injury Scale (AIS) and surgical procedure codes was retrieved from the Oslo University Hospital Trauma Registry for patients with bicycle-related injuries from 2005 through 2016. Outcomes were serious head injury defined as maximum AIS severity score ≥ 3 in the AIS region Head, any cranial neurosurgical procedure, and 30-day mortality. Results: A total of 1256 hospitalized bicyclists were included. The median age was 41 years (quartiles 26–53), 73% were male, 5.3% had severe pre-injury comorbidities, and 54% wore a helmet at the time of injury. Serious head injury occurred in 30%, 9% underwent a cranial neurosurgical procedure, and 30-day mortality was 2%. Compared to non-helmeted bicyclists, helmeted bicyclists were older (43 years, quartiles 27–54, vs. 38 years, quartiles 23–53, p = 0.05), less often crashed during night-time (21% vs. 38%, p < 0.001), less frequently had serious head injury (22% vs. 38%, OR 0.29, 95% CI 0.22–0.39), and less often underwent cranial neurosurgery (6% vs. 14%, OR 0.36, 95% CI 0.24–0.54). No statistically significant difference in 30-day mortality between the two groups was found (1.5% vs. 2.9%, OR 0.50, 95% CI 0.22–1.11). Conclusion: Helmet use was associated with fewer and less severe head injuries and fewer neurosurgical procedures. This adds evidence to the protective capabilities of bicycle helmets. [ABSTRACT FROM AUTHOR]