Objective: To estimate the motor vehicle crash rate in a cohort of older drivers from a rural community and to identify health-related conditions that increase their risk for crash involvement.
Design: Cohort study with 5 years of crash-record surveillance.
Setting: The Iowa 65+ Rural Health Study, one of four Established Populations for Epidemiologic Studies of the Elderly (EPESE).
Participants: A total of 1791 drivers aged 68 years and older.
Main measures: Exposure measures of physical, mental, and sensory well-being from a health interview survey; outcome measure of police-reported crashes maintained by the Iowa Department of Motor Vehicles.
Results: Between 1985 and 1989, 206 drivers were involved in 245 state-recorded crashes. The estimated annual crash involvement rate for these rural older drivers (28 per 1000 driving-years) was about 20% less than the national average for drivers aged 65 years and over (36 per 1,000). An increased risk for motor vehicle crashes was associated with episodes of back pain (Relative Risk = 1.4, P < .05), use of nonsteroidal anti-inflammatory drugs (RR = 1.7, P < .01), and poor performance on a free-recall memory test (RR = 1.4, P < .05).
Conclusions: If these and other geriatric conditions are confirmed as risk factors for motor vehicle crashes, medical guidelines for license renewal may need updating and health professionals may need new instruments to detect older patients at high risk for unsafe driving.