Media Release

September 21 2009

On-road assessment key in driving and dementia

Driving safety and ongoing positive mobility options must be addressed at some point in the progression of dementia UniSA research into on-road driving assessments for people with dementia will be presented at the National Dementia Research Forum in Sydney this week, as part of Dementia Awareness Week.

Occupational therapist Angela Berndt from UniSA’s School of Health Sciences will present a poster session to the nation’s leading dementia researchers on how to achieve the ‘Goldilocks Point’ in driving assessments – ‘not too easy, not too hard ... but just right’.

Mrs Berndt says at some point in the progression of dementia, driving safety and ongoing positive mobility options must be addressed.

“Dementia inhibits a person’s driving capacity through poor navigation skills, poor memory of specific rules, and slowed or confused operation of specific car components such as brakes or gears,” Mrs Berndt said today, on World Alzheimer’s Day.

“One method to measure driving capacity is the on-road assessment. But the design of on-road assessment influences driver errors – there has to be the right balance between easy and demanding driving conditions.”

Mrs Berndt, along with Head of UniSA’s School of Health Sciences Professor Esther May and Professor Peteris Darzins from Monash University, analysed the on-road performance data gathered from a dementia and driving study of 115 drivers who participated in an occupational therapy on-road assessment in order to further validate the task inclusions in the ‘just right’ assessment.

The assessment, conducted in dual controlled vehicles over an hour’s drive, included stop and give way signs, u-turns, school zones, lane changes and speed zones.

Mrs Berndt said 50 drivers passed the test, whereas 65 failed.

“Those with moderate to severe dementia failed the test, while those with very mild dementia either passed or failed,” she said.

“This study supports previous research that dementia severity appears to predict performance in the upper severity ranges of dementia – moderate to severe, and so may assist in cessation or other recommendations of an on-road assessment.

“For drivers with very mild to mild dementia, preservation of function appears to maintain driving capacity for some drivers longer than others, suggesting that on-road assessment is warranted with very mild dementia in order to identify those who might be at driving risk.

“Ongoing reassessment, at least every six months, and monitoring of drivers with mild dementia who may pass an on-road assessment is also indicated, due to the progressive nature of dementia.”

Mrs Berndt said the design of on-road assessments influences driver errors and there has to be the right balance between easy and demanding driving conditions.

“If there are too many traps, then too many drivers will make too many errors, but if there are too few traps, too few drivers will make errors,” she said.

“From the analysis of the on-road performance data, we found an ideal on-road driving assessment that would be both sensitive and specific would include at least three repeats of high demand tasks likely to elicit critical error and of low demand tasks likely to support intact driving performance.”

Mrs Berndt presents the research on Thursday and Friday this week at the Wesley Centre, Pitt Street, Sydney.