Motor Vehicle Injuries and Screening Tools of Unsafe Driving in Older Drivers

Among drivers aged 65 years and older, motor vehicle crashes (MVCs) are the first leading cause of injury death. Unfortunately, this major public health problem is still neglected in Taiwan. After controlling for travelled miles, older drivers are 7-times more likely to die than drivers aged 45-54 years and have the same highest risk of MVC as young drivers. Furthermore, 60%~95% of MVC deaths in older drivers are attributable to physical fragility. There is no screening test for fit to drive to older divers in Taiwan when their driving licenses are renewed. However, an appropriate screening tool of the fit to drive is beneficial to identify a high-risk group of occurring a MVC as well as to enhance effective interventions for reducing MVCs. To address important MVC-related issues in older drivers, this 3-year project proposes a 2-year prospective cohort study and a case-control study. The cohort study will identify performance-based tools which can effectively screen out unsafe older drivers, while the case-control study will supplement information on injury patterns and risk factors for severe MVC injuries among older drivers. In the first year of this project, the cohort study plans to recruit 498 community-dwelling older drivers and its baseline data will be used to examine the correlations between visual, cognitive, and physiomotor functions. Follow-up telephone contacts will be conducted at 3-month intervals over the study period to ascertain occurrences of MVCs and driving cessation as well as to estimate kilometers of travel for each participant. In the second year, a matched case-control study of 145 cases with severe MVC injuries, 290 emergency-room controls with mild motor vehicle injuries, and 290 gas station controls will be conducted to examine crash types and injury patterns of MVC, as well as risk factors of severe injuries in older drivers. In the third year, three specific aims of the 2-year prospective cohort study will be completed, including investigating predictive ability of visual, cognitive, and physiomotor functions for occurrences of MVCs, comparing predictive ability among three cognitive measures (the Mini-Mental State Examination, Mattis’s Dementia Rating Scale, and Trail Making Test) and 5 physiomotor measures (the grooved pegboard test, grip strength, timed up & go, functional reach, and Tinetti’s balance test), and examining factors associated driving cessation in older drivers. Moreover, the three specific aims of the cohort study for older motorcyclists only will also be examined, since motorcycles are the most commonly used motor vehicles in Taiwan.