Mental illness and medical fitness may make a larger contribution to road trauma than previously thought, a study has revealed.
The Austroads report, prepared on behalf of government-based motoring authorities throughout Australia and New Zealand and released yesterday, found drivers, motorcyclists, pedestrians and cyclists with mental illnesses or life-threatening conditions accounted for 11 per cent of almost 1500 road trauma victims admitted to the Royal Adelaide Hospital over a three-year period, stepping up to 12.7 per cent if possible cases were added.
Alarmingly, the University of Adelaide Centre for Automotive Safety Research study found that in almost one in four crashes linked to a medical condition, the driver lost consciousness behind the wheel. Almost one in five drivers who had reported a pre-existing medical condition had a seizure behind the wheel.
Advertisement: Story continues below
People with a mental illness accounted for one-fifth of all crashes investigated, including those drivers making a suicide attempt, the study says.
Of all the crashes, almost one in five were also intoxicated at the time of the incident, recording an alcohol level above the 0.05 legal limit.
More than half of the participants in the survey with alcohol dependence noted as a condition in their medical records were above the legal limit at the time of their crash.
When it came to incidents related to medical conditions, drivers aged over 70 accounted for almost one in three crashes despite only representing 11.4 per cent of the participants in the study, the research showed.
In contrast, drivers identified as being involved in a crash resulting from a mental illness or suicide attempt were much younger, with most aged between 20 and 50 years. As many as 40 per cent of crashes for this group were into fixed objects, it noted.
According to police reports, drivers with a medical condition were at fault for 95 per cent of the crashes relating to that category, compared with 68.4 per cent for all other participants.
Medical reports also showed that of the 41 drivers who lost consciousness in the lead-up to a crash, 10 had a history of two or more collapses in the weeks and months preceding it.
‘‘In these cases, the episodes had not been medically investigated until the person was involved in the crash,’’ the study said.
‘‘The reasons why these cases were not investigated prior to the crash event are not available in most cases, but it is likely that there were some cases involving the participant not seeking earlier medical attention and some where medical investigation was not undertaken. There is a need to explore these aspects further.’’
The study concludes that older drivers need to be regularly assessed for their medical fitness to drive, particularly for those ‘‘demonstrating age-related functional decline and those at increased risk as the result of the effects of multiple co-morbid medical conditions’’.
It also suggests closer monitoring is needed to ensure drivers with alcohol dependence or a mental illness voluntarily report their condition to licensing authorities, and ensure licence holders and doctors are better informed of the risks of driving with particular medical conditions.
The study also noted that some parts of the findings needed further investigation.