Fitness to drive in older persons with early stage dementia

In the Netherlands, about 250.000 people are suffering from dementia. It is
expected that this number will be doubled in 2040. Research shows that car
drivers with dementia have an increased risk of being involved in a road crash;
this risk is about the same as the risk of driving under influence of alcohol
or drugs. However, in early stages of dementia, the majority of drivers can
still drive safely. This is the reason why Dutch drivers with (very) mild
dementia are still considered fit to drive, at least when they perform
adequately on a number of neuropsychological tests and on an on-the-road
driving test carried out by the Dutch Licence Agency CBR. The
neuropsychological tests have recently been developed in FitCI: a joint
research programme by SWOV, RuG, UMCG and CBR. De driving licence can be
renewed for 1, 2 or 3 years, depending on the results of the neuropsychological
tests and the on-the-road driving test.

Although the practical driving test is carefully constructed, it is a
momentarily measurement in specific circumstances. We would like to know
whether the results of the neurpsychological tests and the driving test are
good predictors of daily driving behaviour. Also, we would like to validate the
results with a new patient group. Finally, given the progressive nature of
dementia, we would like to know for how long this prediction is valid.

The study aims to improve the existing screening procedure for car drivers with
dementia. It validates the current testing procedure and the decision procedure
regarding fitness to drive. This is supposed to be beneficial to the safety of
the driver, his passengers (if applicable) and other road users. Furthermore,
the study may decrease the chance that the licence is withdrawn unneccesarily,
and thus independent mobility may be maintained for a longer time. This is
considered beneficial for the car driver and his family. The aim of the study
is also that the driving test will not be necessary anymore for some groups of
patients.

The duration of the study is three years. During this period, 120 car drivers
with (very) mild dementia and 40 car drivers without dementia symptoms are
followed for two years. All 160 participants take part in the FitCI test
procedure three times: at the start of the project and after that every 6 to 8
months. The FitCI procedure includes an interview with the participant and
partner, a neuropsychological examination and a test drive in a driving
simulator. Furthermore, at the start of the project and in the end of the
research period, and possibly once in between, a practical on-the-road driving
test will be carried out. In order to observe day-to-day driving behaviour, an
in-car device will be mounted in the participant's own car. This device
collects camera footage and registers driving parameters. The main research
question is whether participants who have been qualified for license renewal
are indeed safe drivers during the whole period for which the licence renewal
applies.

Participants will visit SWOV three times in a 2-year period, to participate in
neuropsychological tests and test drive in the simulator. This takes about 3
hours per visit; breaks will be held whenever the participant feels the need.
During each visit, an in-car device with camera's will be installed in the
participants' car and will stay there for two months. After two months, the
researchers will make an appointment with the participants to uninstall the
device.

After the first and the last testing day, and possibly once in between, an
appointment will be made on a separate day with the licence agency (CBR) for
the on road driving test. The on road driving test takes one hour of the
participants' time. Persons with (very) mild dementia (CDR 0.5 en CDR 1) will
generally be asked to participate shortly after having received the diagnosis.
Participation has the advantage of having a comprehensive driving evaluation
without direct consequences for their driving license, including an on road
test by the CBR. However, the results of the on-road test can labelled as
official if a subject asks for it. This could occur in case he/she performed
adequately on the on-road test; in that case the license will be renewed for a
year. In case the subject failed the on-road test, he or she will, depending on
the performance, be advised to take driving lessons and have an official
examination afterwards, or to stop driving and handing in the license. This
advice will not be reported to the CBR however. Besides, persons with CDR=0.5
and a positive result in the on-road test, have the advantage that the
neuropsychological assessment which is essential for an extension of the
driving license longer than a year is without costs for them. In all cases the
results of the examination will be discussed with the subjects and families.

While driving the driving simulator it is possible that the participant will
suffer from 'simulator sickness'. We will inform the participant beforehand
that this is possible. During the driving simulator tests, the physical
well-being of the participants is being monitored carefully. If the participant
is not feeling well, the simulator is stopped immediately. The driving
simulator-part of the study will be terminated for this participant. When the
participant is feeling well enough to go home, he/she is allowed to do so.