With a predictable relationship between driving safety and mild cognitive impairment (MCI) or early dementia yet to be firmly established, this project aimed first to describe the on-road driving performance of a group of older people with MCI or early dementia, and second to validate a new cognitive screening instrument, the Maze Task, developed to indicate the likely competence of older drivers with MCI or early dementia. 115 community-dwelling older drivers with MCI or early dementia were recruited through their association with the Memory Clinic, RGH. Participants completed the Maze Task, and immediately thereafter, a standardized on-road driving test. 70% of participants failed the on-road test, most broke an important road law, and nearly half required physical intervention to prevent a car crash. Almost 50% of those with MCI failed the driving test, while 75% of those with early dementia failed the same test. On-road driving faults were related to poor planning and observation skills, an inability to monitor and control the speed of the car, poor car positioning, confusion with pedals, and a lack of anticipatory or defensive driving. These results raise concern about the safe driving competence of older drivers with MCI or early dementia, and highlight the need for cognitive screening of driving ability. The Maze Task was found to be simple, brief to administer and score, and safe and acceptable to study participants. Maze Task scores were not influenced by sociodemographic variables. The association between the Maze Task and known measures of attention, visuoconstructional skills, and executive functions of planning and foresight may explain its predictive validity. That is, the Maze Task discriminated with high accuracy those participants who passed the on-road test from those who failed the same test. Cognitive screening of older drivers in the primary care setting, with the Maze Task, requires further investigation. (Author/publisher)
Abstract