Frequently Asked QuestionsFact: Medically impaired drivers are significantly more likely to have an at-fault crash. Conditions that cause cognitive impairment are associated with the most decline in safety. For example, the increased crash risk for patients with cognitive impairment is similar to the crash risk of an alcohol-impaired driver. However, unlike alcohol impaired drivers, those with cognitive impairment have reduced compence 24 hours a day. (Diller, Cook et al. 1998)(Carr, 1997) (Kruger 2000), How Many Patients Are Cognitively Impaired? Fact: 25% of seniors over 65 years of age have cognitive impairment (8% suffer a dementing illness & 17% are cognitively impaired due to illness other than dementia). The prevalence of dementia increases with age. 65 - 74 years = 2.3% have dementia; Increasing to 43.5% in those aged 84+.
(Image Source: CSHA 1991) Do doctors effectively identify cognitive impairment in their clinics? NO Fact: Studies have shown that most patients with cognitive impairment are undiagosed. For example, a study by Valcour, Masaki et al (2000) showed that 67% if patients with dementia are missed in the primary care setting & 90% of dementia cases are missed when the impairment is mild. Are medically impaired seniors driving? YES Fact: In Australia, 42% of men with probable dementia and 63% with possible cognitive impairment were classified as current drivers. For women, 11% with probable dementia and 19% with possible cognitive impairment were classified as current drivers (Ross, 2009) “57% of seniors with some medical impairment are drivers. One out of every four elderly people with serious cognitive problems has a valid driver's license, 72% of those with serious cognitive problems drive at least 3 times a week” (Bess, 1999) “The literature shows that individuals with dementia continue to drive for approximately 4 years after the onset of symptoms. Because the average duration of dementia is about 8 to 10 years after the onset of symptoms, it appears that persons with dementia continue driving well into the disease.” (Hopkins, 2004)
Do senior drivers have high crash rates? Fact: Only the youngest, inexperienced drivers have higher crash rates than senior drivers when the amount of kilometers driven is taken into consideration. However, it is now recognised that these high crash rates are not so much due to age itself but due to the effect of medical conditions which are more common as we age.
(Source: Australian Transport Safety Bureau)Do medically impaired drivers know when to stop by themselves? Fact: Many older drivers effectively regulate their own driving. However, drivers with cognitive impairment often lack insight and are unlikely to know that they are unsafe. Few realize their skills are compromised & therefore continue to drive long after their skills have declined to a dangerous level. Is the Mini Mental state exam an accurate assessment of driving ability? NO Fact: Correlation statistics showed MMSE accounted for less than 9% of driving performance. At a score of 24 the MMSE identified only about 50% of unsafe drivers and incorrectly identified about 20% of safe drivers as unsafe.
Do doctors that raise the driving concerns with patients lose them? NO Fact: The key to not losing a patient is referring them for an independent driving evaluation. In a study of 117 consecutive patients advised to stop driving after a DriveABLE Assessment, no patients changed doctors. (Dobbs, B) Is there reason to be concerned about older drivers and driver safety? YES Fact: Crashes for drivers aged 65+ have risen 47% (1979-1995) while crashes for drivers under 65 decreased 8.8%. The issue of driving and cognitive impairment is only going to become more concerning with the aging population. The graph below shows the predicted percentage increase in driver fatalities and injuries between 2001 - 2026, the period during which the baby boomers will be in their senior years.
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