Sex-Based Differences in Bicycle Helmet Protection. (16th November 2020)

• Record Type: Journal Article
• Authors: Feler, Josh; O'Connor, Rick; Davis, Kimberly A; Gerrard, Jason L; Maung, Adrian
• Is Part Of: Neurosurgery. Volume 67(2010)Supplement 1
• Publication Date: 2020-11-16
• Subjects: Nervous system -- Surgery -- Periodicals; 617.48005
• DOI: 10.1093/neuros/nyaa447_427
• Languages: English
• ISSNs: 0148-396X

Abstract

Abstract: INTRODUCTION: Bicycle use is becoming more prevalent in cities. Although helmets have been shown to have protective effects against traumatic brain injuries and death, it is unknown whether the protective effects of bicycle helmets are equivalent between males and females. METHODS: Patients 18 years or older presenting after bicycle crash were identified in the 2017 National Trauma Data Bank®. Demographics, helmet use, accident mechanism, injuries, procedures and short-term outcomes were extracted. Multivariate logistic regression models with an interaction term for sex and helmet use were calculated for cranial pathologies, need for cranial surgery, and outcomes. The exponentiated regression parameter for this interaction term equals the ratio of the aOR for the outcome with helmet use for females over the same for males (aORR). Significance was defined as a two-sided P -value < .05. RESULTS: 18, 604 patients were identified, 18.0% of whom were female. Helmet use was greater in females (39.4% vs 35.7%, P < . 001). Fewer crashes amongst females involved a motor-vehicle (32.2% vs. 40.1%, P < . 001). Helmets were associated with a significantly less risk reduction for women against severe head injury (head AIS > 3) (aORR 1.40), ICH of any type (aORR 1.58), subarachnoid hemorrhage (aORR 1.58), subdural hemorrhage (aORR 1.61), skull base fractures (aORR 1.63), skull vault fractures (aORR 1.49), concussion (aORR 1.36), need for cranial surgery (aORR 1.64), and death (aORR 2.32). CONCLUSION: Bicycle helmets may offer less protection to females than males when controlling for age, mechanism, and anticoagulation. The cause of this difference is uncertain, but there may be intrinsic incompatibility between available helmets and female head size/shape or gender disparity in helmet testing standards. Further research is required to clarify the mechanism for this observed difference.