No abstract

No abstract

Older drivers have more accidents per miles driven than any other age group and tend to have significant impairments in their visual function, which could interfere with driving. Previous research has largely failed to document a link between vision and driving in the elderly. We have taken a comprehensive approach by examining how accident frequency in older drivers relates to the visual/cognitive system at a number of levels: ophthalmological disease, visual function, visual attention, and cognitive function. The best predictor of accident frequency as recorded by the state was a model incorporating measures of early visual attention and mental status, which together accounted for 20% of the variance, a much stronger model than in earlier studies. Those older drivers with a visual attentional disorder or with poor scores on a mental status test had 3-4 times more accidents (of any type) and 15 times more intersection accidents than those without these problems.

Background: We live in a world where information is presented in a time-limited fashion and successful adaptation is dependent on time-limited responses. Slowed visual-processing speed is common among older adults. Its impact on everyday task performance is not clearly understood. Objective: The goal was to determine whether visual-processing speed, as well as memory and inductive reasoning, are independently associated with the time required by older adults to complete instrumental activities of daily living typical of everyday life. Methods: Five timed instrumental activities of daily (TIADL) tasks were administered to 173 older adults (ages 65–90 years) along with assessments of visual-processing speed, memory, and inductive reasoning. The dependent variable was the time required to perform the task (e.g., finding a telephone number, making change, finding and reading the ingredients on a can of food, finding food items on a shelf, reading instructions on medicine container). Medical and functional comorbidities known to affect task performance were measured in order to adjust for their impact on the dependent variable. Other measures of everyday task competence (Everyday Problems Test, Observed Tasks of Daily Living, questionnaire on IADL difficulties) were also administered in order to determine to what extent existing measures of everyday performance are associated with TIADL performance. Test-retest reliability of the TIADL score was assessed in a separate sample. Results: Although memory and reasoning were crudely related to the time needed to perform the TIADL tasks, only processing speed was independently associated with TIADL scores. Those older adults with slow processing speed were more likely to require longer times to complete everyday tasks. Previously developed measures of everyday task competence (e.g., Everyday Problems Test, Observed Tasks of Daily Living) based on accuracy scoring did not strongly predict TIADL performance. Conclusion: These results suggest a unique role for an everyday competence test that focuses on the timely completion of everyday tasks, rather than on an assessment of accuracy alone. TIADL measures may prove useful in evaluating the everyday effectiveness of cognitive interventions targeted at increasing information-processing speed.

Mobility in older adults is typically discussed in terms of component maneuvers including analysis of gait and postural instability; activities that depend on mobility such as bathing, dressing, or shopping; or adverse events during mobility such as falls or motor vehicle crashes. None of these approaches reflects a key aspect of mobility—the extent of movement within a person's environment, or life space in the gerontological literature. Here we describe this concept as it applies to mobility and present a questionnaire instrument designed to measure life space in community-dwelling older adults. Results indicate that the Life Space Questionnaire (LSQ) is reliable and has construct and criterion validity in a sample of olderadults. The LSQ can be used to establish the spatial extent of an older person's mobility and may ultimately be useful as an outcome measure in studies evaluating interventions designed to enhance mobility and independence in community-dwelling older populations. In broad terms, mobility refers to a person's purposeful movement through the environment from one place to another. Mobility can be conceptualized as a continuum from bed bound (immobility) on one extreme to making excursions to distant locations on the other extreme. With increasing age, threats to mobility increase in prevalence and include problems such as