Older drivers are often presented as a "traffic safety problem". Age-related medical conditions such as dementia and stroke impair cognitive functions that are crucial for safe driving. Uncertainty remains regarding the most appropriate clinical methods to assess driving fitness in these patient groups. Furthermore, preclinical dementia and cognitive impairment may affect driving performance and lead to an increased crash risk. The first general aim of the thesis was to investigate the presence of cognitive impairment (CI) in crash-involved persons from the general older driving population. The second was to study different methods to evaluate the fitness to drive in clinical groups of older adults. In study I a group of fatally crashed older drivers was investigated regarding neuropathology and informant-reported functioning. There were moderate to frequent densities of neuritic plaques (NPs), the hallmark of Alzheimer's disease, was in 25%. Such densities indicate the presence of Alzheimer's disease in persons 65 to 75 years. Participants in study II were older drivers with temporarily suspended licenses due to unsafe driving. There were two subgroups: a) drivers involved in crashes and b) those with moving traffic violations. Study III was a three-year follow-up investigation of study II. Mortality tended to be higher in the case group, as compared to controls, and the presence of dementia or CI differed between groups. Study IV concerns stroke patients. The usefulness of a screening battery, the SDSA, to determine driving fitness, was evaluated. Study V deals with driving tests among older patients with CI. The outcome (pass/fail) of the tests was compared for two groups: 1) patients driving their own cars and 2) patients driving dual-control cars. Older drivers with demonstrated unsafe traffic behaviour should be cognitively assessed. This should also be the case for older license holders with medical conditions susceptible to cause CI. However, in a policy perspective, it is necessary to carefully weigh the individual and societal consequences of license revocation against the crash risk of older drivers with CI. (Author/publisher)
Samenvatting