Visual factors that influence driving status in older adults, and risk of long-term care entry in non-drivers

Background. New strategies are needed to reduce the fatal crash rate of older adults. One strategy could be to seek out those with a risk factor for crash who have not already made changes to enhance their driving safety. Since vision is vital to driving safety, studies are needed that describe what changes are made to driving after losing visual function. However, given the importance of driving, it is also important to understand whether there are consequences with regard to living independence for those who do not drive.; Methods. Data were used from the Salisbury Eye Evaluation project, a prospective, population-based study of 2,520 older adults (1993--2003). Objective measures of visual function were obtained. Driving information was obtained via self-report. Additional data on long-term care entry and on driving were collected by an interviewer-administered questionnaire given via telephone to participants or proxies. Regression procedures were used to evaluate the objectives.; Results. Multiple measures of visual function were associated with making modifications to driving behavior, like reducing mileage or avoiding high-risk driving situations, and with driving cessation. Four measures of visual function, which included acuity, contrast sensitivity, central and lower peripheral visual fields, were associated with driving change in a step-like manner. Furthermore, the type of change to driving behavior depended on what type of visual function was affected.; Finally, former and never drivers had a higher risk of long-term care entry after adjusting for demographic and health variables in time-dependent models (HR = 4.85, 95% CI 3.26, 7.21 and HR = 3.53, 95% CI 1.89, 6.58). In addition, having no other drivers in the house was an independent risk factor for LTC entry (HR = 1.72, 95% CI 1.15, 2.57).; Conclusions. Older adults with worse scores in various measures of vision, in general, were more likely to stop driving and to modify their driving to ensure safety. Being a non-driver as an older adult and having no other drivers in the house were both independent risk factors to enter long-term care. Strategies to develop better transportation programs targeted to older adults may help to encourage self-regulation of driving, maintain living independence, and improve quality of life.