The Medically At-Risk Driver –
Cognitive Impairment Leads the Way
Bonnie M. Dobbs, PhD* and Allen R.
Dobbs, PhD†
* University of Alberta, Edmonton, Canada
†
DriveABLE™ Assessment Centres Inc.
Paper presented the British Columbia Injury Prevention 2006
Conference
March 1 – 3, Vancouver, BC
The Older Driver vs. The Medically
At-Risk Driver
• Older drivers: one fastest growing
segments of driving population
• By 2024: 1:4 drivers will be over the age
of 65
• Older drivers driving more and longer
into old age
How ‘Safe’ Are Older Drivers
• Most older drivers are safe drivers
• Self-regulation is common (rush hour, freeways,
during inclement weather, etc.)
• Self-restrictions due to recognition of changes in
driving ability
• BCAA Traffic Safety Foundation Mature Driver
Program (Living Well Driving Well)
http://www.tsf-bcaa.com/links_and_resources_4
• Despite self-regulation, crash rates taking amount of
driving into consideration are high
Driver Fatality Rate (per 100 million VMT)
10
9
Fatality Rate
8
7
6
5
4
3
2
1
0
16 17 18 19 20- 25- 30- 35- 40- 45- 50- 55- 60- 65- 70- 75- 80- 85+
24 29 34 39 44 49 54 59 64 69 74 79 84
Source: FARS 2001 and NHTSA 2001
Driver Age Group
Crashes /km driven
Crash Rate by Age *
Risk
Medical
16
30
* Taking exposure into account
50
70
40
Trends in Traffic Safety
19831987
35
C
r
a
s
h
e
s
30
19881992
25
20
19931997
15
10
5
19982002
0
<6
6-15
16-24
25-64
65-74
75+
(Source FARS, 1983-2002)
Who Is Most At-Risk?
• Not ‘Older Drivers’ but Medically AtRisk Drivers
• A number of chronic medical conditions
put individuals at risk (those conditions
can occur at any age but are more
likely to occur as one gets older)
• Also need to take into consideration the
medications that are used to treat those
illnesses
‘Red Flags’
Red Flags*
• Cardiovascular disease (e.g., congestive heart failure, cardiac
arrhythmia)
• Metabolic disease (e.g., diabetes, hypothyroidism)
• Cerebrovascular disease (e.g., stroke, arteriosclerosis)
• Renal disease (chronic renal failure)
• Neurological disease (e.g., head injury, Parkinson’s Disease, Multiple
Sclerosis, tumor, narcolepsy, sleep apnea)
• Dementia (e.g., Alzheimer disease, multi-infarct dementia, frontal
temporal dementia, Pick’s Disease)
• Respiratory disease (e.g., chronic obstructive pulmonary disease,
respiratory failure)
• Psychiatric illness (e.g., schizophrenia, depression)
• Medications (e.g., anti-depressants, other medications having
prominent central nervous system effects)
*From B. Dobbs (2002) NHTSA report
Increased Crash Risk
(At-Fault Crashes)*
•
•
•
•
•
•
•
•
Visual Acuity
Diabetes
Cardiovascular
Pulmonary
Psychiatric
Epilepsy
Neurological
Cognitive Impairment
* Diller et al. (1998) (Unrestricted drivers)
2.8
2.2
1.8
2.1
2.5
3.0
5.1
7.6
Scope of the Problem
• 8% of Canadians 65+ have a dementia,
another 17% have some form of
cognitive impairment (CSHA, 1994)
• All individuals with a progressive
dementia will become unsafe to drive at
some point in their illness
Identifying Those At-Risk
• Diagnosis alone insufficient for revocation of driving
privileges
• Standard tests (e.g., MMSE) are not good predictors
of driving abilities
• Cannot rely on patient/caregiver reports
• Medical conditions can be used as “Red flags”
• Conversations about driving need to start early
• Medical Conditions-Chronic Outcomes: decisions
need to be made on an individual basis (e.g.,
scientifically based on-road driving assessment)
Warning Signs
•
•
•
•
•
•
•
•
•
Unaware of driving errors
Getting lost or confused while driving
Other drivers honking
Trouble navigating turns
Difficulty staying in lane
‘Missing’ traffic signs
Near Misses
Unable to keep up with speed of traffic
Scrapes or Dents on Car and/or Garage
Support Critical in the Stopping
Driving Process
• Insight often impaired – Don’t understand
why driving privileges revoked
• Loss of driving privileges a life altering event
for many-associated with reductions in
mobility, independence, negative emotions
• Affects individuals and families
Driving Cessation Support Groups
• DCSG developed and tested over a 2
year period (funding from Alzheimer Canada)
• Specialized support groups specifically
for loss of driving privileges effective
(Dobbs et al., 2005)
Conclusions
• Traffic safety strategies need to take into account the
need for mobility and safety
• Goal is to promote the continued mobility of those
who are safe to drive
• For those who are unsafe, revocation of driving
privileges is needed
• Critical that we develop support programs and
alternate means of transportation to ensure the
continued mobility for those who are no longer able to
drive