Are there sex differences in crash and crash-related injury between men and women? A 13-year cohort study of young drivers in Australia

BACKGROUND: Young men have long been known to be disproportionately impacted by road crash and crash-related injury compared to young women and older drivers. However, there is limited insight into how sex differences in crash and crash-related injury changes over time as men and women get older and gain more driving experience. To explore sex differences in crash and crash-related injury, we undertook a sex disaggregated analysis in a large longitudinal cohort of over 20,000 young drivers in New South Wales, Australia, for up to 13 years after they first attained their independent car driver licence. METHODS: DRIVE Study survey data from 2003-04 were linked with police, hospital and deaths data up to 2016. Sex differences were analysed using cumulative incidence curves investigating time to first crash and in negative binominal regression models adjusted for driver demographics and crash risk factors. RESULTS: After adjusting for demographics and driving exposure, compared with women, men had 1.25 (95% CI 1.18-1.33), 2.07 (1.75-2.45), 1.28 (95% CI 1.13-1.46), 1.32 (95% CI 1.17-1.50) and 1.59 (95% CI 1.43-1.78) times higher rates of any crash, single vehicle crash, crash on streets with a speed limit of 80 km/h or above, crash in wet conditions and crash in the dark, respectively. By contrast, men were less likely to be involved in crashes that resulted in hospitalisation compared to women 0.73 (95% CI 0.55-0.96). CONCLUSIONS: Young men are at increased risk of crash, and this risk persists as they get older and gain more driving experience. Despite lower risk of crash, women are at higher risk of crash related injury requiring hospitalisation. These differences in men's and women's risk of crash and injury signal the need for better understanding of how sex and/or gender may contribute to risk of crash and injury across the life-course.