The Alzheimer's Disease and Memory Disorders Center

A Longitudinal Study of Drivers with Dementia

Principal Investigator: Brian R. Ott, MD

This is a longitudinal research project which examined changes in on-road driving performance and changes in cognition among actively driving subjects with mild Alzheimer's disease. It is well recognized that dementia is a risk factor among the elderly for motor vehicle crashes and fatalities. Degenerative dementias such as Alzheimer's disease, because of their progressive nature, eventually lead to driving incompetence in all cases. A critical question that faces clinicians in everyday practice is when to advise patients with early disease to abstain from driving.

Because patients with Alzheimer's disease may still be competent to drive if their dementia is in its earliest and mildest stage, and because driving is an important factor in maintaining autonomy for elders, licenses should not be revoked based on arbitrary decisions about one's memory ability. Annual road testing for driving competence of all elders or even all elders with dementia is neither practical nor economical. Therefore, an effective screening instrument is badly needed. Knowledge about the actual driving impairments that occur in dementia patients that lead to hazardous driving and how they relate to changes in neuropsychological function over time is critical to the development of a valid screening tool.

Drivers with early stage Alzheimer's disease were enrolled in this study and followed every six months over two to three years. A validated road test protocol was  administered by a professional driving instructor. Computerized neuropsychological tests of visual perception, visual attention, and executive function were administered concurrently. It was predicted that the earliest evidence of driving impairment would be associated with disturbances in visual perception and attention. In more advanced stages of dementia, when subjects are most likely to be judged as incompetent drivers, there would be prominent deficits in executive function as well.

The longitudinal design of this study has given important insights into the evolution of driving impairment among Alzheimer's disease patients and will assist in the future development of screening tests to identify hazardous drivers who would be likely to fail a performance based road test.

Funded by the National Institute on Aging, 1RO1 #AG016335, Ott (PI), 9/15/01-4/30/07

Naturalistic Assessment of the Driving Ability of Cognitively Impaired Elders

Principal Investigator: Brian R. Ott, MD

This research examined the driving abilities of elderly drivers with and without cognitive impairment related to probable or possible Alzheimer’s disease. It expanded our knowledge about cognitively impaired older drivers and extend the observations made during our prior research studies from RO1#AG16335, entitled “A Longitudinal Study of Hazardous Drivers With Dementia.”  Specifically, we examined older drivers with mild Alzheimer’s disease, questionable or mild dementia, and no cognitive impairment.  We compared performance on specific computerized measures of visual attention and executive function to digital camera recordings of subjects in their own cars, driving in their natural environments. We performed a similar analysis of the computerized measures for the same subjects completing an extended version of the Rhode Island adaptation of the Washington University Road Test.   Driving outcomes will be scored on continuous rating scales as well as global assessments of safety. These assessments will be done at baseline and repeated at one year.

This was the first study of its kind to directly examine cognitively impaired elders in their natural driving environments.  We compared driving performance in the structured road test setting to performance in the unstructured natural setting.  This comparison helped us to understand the validity of the road test as a ”gold standard” for driving assessment in this population.  Furthermore, we characterized and quantified the types of errors made in driving, by use of a reliable rating scale of the video recordings in both familiar and unfamiliar driving environments. 

Secondary goals of this research included examination of the accuracy of family members and caregivers in predicting driving performance ratings by a professional driving instructor in the natural and road test settings. 

Funded by the National Institute on Aging, 2R01 #AG016335, Ott (PI), 5/15/07-4/30/13            

Secondary Analysis of Naturalistic Driving Data in Aging and Dementia

This study is analyzing naturalistic driving data obtained from older drivers with and without dementia using advanced GPS and computerized video programs that will result in a rich dataset that can then be compared to data obtained from standardized on-road and cognitive tests in the same individuals. 

Funded by the National Institute on Aging, #1R03AG046472, Ott(PI), 9/15/2014-8/31/2016

Video Feedback Intervention for Cognitively Impaired Elders

Principal Investigator: Brian R. Ott, MD

Studies of teens and professional drivers have demonstrated benefits of video feedback monitoring to improve safe driving.  Our pilot work shows potential efficacy of this technology for improving safe driving in people with mild cognitive impairment and early Alzheimer's disease (AD). The goals of this clinical trial are to 1) document real-time impaired driving behaviors, and 2) reduce their occurrence, to improve the safety of cognitively impaired elders who continue to drive.  This will be accomplished by placing small digital video event recording devices in the vehicles of 60 older cognitively impaired drivers.  A 3-month baseline will establish the frequency of unsafe driving events, followed by a 3-month video feedback intervention during which the driver and family member will review the video recorded errors on a weekly basis.  Active treatment will be compared to video monitoring with no feedback.  A 6-month post-intervention phase will establish sustainability of the treatment.  The primary aim is to determine the efficacy of a video feedback intervention for reducing unsafe driving event frequency in older individuals with mild cognitive impairment and early AD relative to passive monitoring.   

Data from two longitudinal studies reveal that the majority of drivers with mild cognitive impairment or mild dementia due to AD continue to drive and can pass a standardized road test, yet such drivers as a group are recognized to be at increased risk for a motor vehicle crash. Research efforts to date have focused primarily on defining indicators for the removal of unsafe drivers from this active population of older drivers.  Little work has focused on improving traffic skills in older adults with mild cognitive impairment and early AD who continue to drive.  This study offers a novel approach to maintaining one of the most complex and important activities of daily living for this group of elders.

Loss of mobility by elders due to enforced driving restrictions resulting from cognitive impairment constitutes a major economic, social and emotional burden for our aging society.  The results of this clinical trial will confirm the potential to improve driving safety among older drivers with cognitive impairment using a behavior modification approach aimed directly at the problem behaviors observed in their natural driving environment.  Knowledge gained about the magnitude and duration of the treatment effect and the potential of using an internet based feedback program will provide the impetus to optimize and ultimately implement the intervention to improve the safety of older drivers with mild cognitive impairment and early AD.  If successful, this technology will provide a means to enhance public safety on the roads that could be adopted immediately in this at-risk group of drivers. The intervention will also maximize the time for independent driving, improving the overall quality of life of these individuals.

 Funded by the Alzheimer's Association, #NPSASA-15-362133, Ott (PI), 9/1/15 – 10/31/19