Effects of aging and risk-taking behaviors on fatal injuries among old motorcyclists in Taiwan: Evidence from 2011 to 2022

Background and objectives Fatality rates of motor vehicle crashes among the old population have risen, primarily in association with age-related declines in health and functional abilities. Comparatively little research has been conducted to examine the impacts of risk-taking behaviors (such as unhelmeted, unlicensed, and drunk riding) on fatalities among old motorcyclists. Materials and methods This study employed the Taiwan National Traffic Crash Dataset from 2011 to 2022 to investigate fatal injuries among old motorcyclists. To identify risk factors associated with injury fatality, chi-square tests were employed. Subsequently, stepwise logistic regression models incorporating multiple variables were constructed to examine these factors. To explore potential interactions between aging and specific behavioral variables, joint effect analysis was performed, followed by a subgroup analysis specific to very old motorcyclists (75 years or above). Results The analyzed dataset comprised 338,231 crashes involving old motorcyclists, of which 2,703 were fatal and 335,528 were nonfatal. A linear relationship was observed between the risk of fatal injuries and increasing age. The adverse effect of aging on fatalities was exacerbated among unhelmeted (AOR = 4.46; CI = 3.79–5.26), unlicensed (AOR = 1.76; CI = 1.55–1.99), and drunk riders (AOR = 5.35; CI = 4.06–7.06). Our subgroup analysis revealed similar detrimental effects of these three behaviors among very old motorcycles when they were unhelmeted (AOR = 3.67; CI = 3.09–4.36), unlicensed (AOR = 1.31; CI = 1.13–1.50) and intoxicated (AOR = 3.06; CI = 2.31–4.06). Further stratification by geographic location demonstrated that certain risk-taking behaviors, such as unhelmeted and drunk riding, were consistently associated with higher fatality rates. Notably, the magnitude of the effects of drunk riding in rural settings on fatal injuries was higher. Conclusions The study established a linear relationship between age and the risk of fatal injuries among old motorcyclists. The three risk-taking behaviors apparently are risk factors for fatal injuries, and evident when motorcyclists were very old. This underscores the importance of tailored interventions targeting individuals aged 75 years or above who engage in unlicensed riding, which remains an important area for continued research.