Driving and Dementia

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Driving and Dementia

• Drs John Puxty and W Dalziel

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Content

• Epidemiology of Aging and Driving issues
• Common Causes of MVAs in the elderly
• Impact of Dementia on Driving safety
• Assessing Driving Capacity

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Epidemiology of the Aging Driver

• Number of accidents increasing
• Motor vehicle accidents per driver is low,
  however the rate per mile per driver is high
• People 75 years and older have the highest
  pedestrian death rates per 100,000 people.
• At age 80 and older, the pedestrian death rate
  per 100,000 among men is more than 3 times as
  high as at age 79 and younger.

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Epidemiology of the Aging Driver

• Number of accidents increasing
• Commonly at intersections or junctions
• About half of fatal crashes involving drivers 80
  years and older occur at intersections and
  involve more than one vehicle. This compares with
  23 percent among drivers up to age 50.

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Epidemiology of the Aging Driver

• Number of accidents increasing
• Commonly at intersections or junctions
• More likely to result in serious injury and
  fatality

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Traffic Deaths by Age 1990-2000
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Fatality Rate by Age and Distance Traveled

• On the basis of estimated annual travel, the
  fatality rate for drivers 85 and over is 9 times
  as high as the rate for drivers 25 through 69
  years old.

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Aging and Fatal Motor Vehicle Accidents

• People age 70 and older have more motor vehicle
  deaths per 100,000 people than other groups
  except people younger than 25.
• The motor vehicle death rate per 100,000 people
  begins to rise among males at age 65. By age 80
  and older, the rate among men is more than twice
  as high as it is at age 40-74.
• At all ages, males have much higher motor vehicle
  death rates per 100,000 people compared with
  females. By age 85 and older, the rate is more
  than 3 times as high among men as among women.
• People 75 years and older have the highest
  pedestrian death rates per 100,000 people.
• At age 80 and older, the pedestrian death rate
  per 100,000 among men is more than 3 times as
  high as at age 79 and younger

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Contributory Factors to high frequency of MVAs

• Aging
• Reaction time choice
• Vision (acuity, peripheral)
• Motor strength
• Physical illness
• Cognitive impairment/dementia
• Vision impairment - cataracts, glaucoma, ARMD
• Hearing impairment
• Neurological disease Seizures, CVA, PD
• Cardiovascular disease (IHD)
• MSK
• Depressive symptoms
• Medications

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Dementia and Driving

• Most drivers with dementia do not have accidents
  many modify their driving and, many voluntarily
  give up driving.
• They do however have an increase (2-5 x) in the
  risk of crashes if they persist in driving.
• If you assess it is safe for them to drive
  REASSESS THE SITUATION AT LEAST ONCE EVERY 6
  MONTHS. Dementia is a progressive condition!

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Risk Increases

• Longer duration of driving with dementia
• Male sex
• Patient who do worse on
• Global measure of severity (CDR)
• Global measure of cognition (MMSE)
• Specific domains of cognition (e.g. visuospatial
  functioning, measures of attention

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Clinical Dementia Rating (CDR) Scale

• Standardized interview of patient and family
  assessing domains of
• Memory
• Orientation
• Judgment / Problem-solving
• Home and Hobbies
• Community Activity
• Personal Care
• CDR Scores
• 0.0 No Dementia
• 0.5 Questionable Dementia
• 1.0 Mild Definite Dementia

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CDR and Driving

• MVAs more likely as CDR gt0 (Johansson et al
  1996)
• 78 of CDR-0 rated as safe drivers vs. 67 CDR
  -0.5 and 41 CDR -1 subjects (Hunt et al 1997)
• Correlation between failure at Road Test and CDR
  rating (Hunt et al 1993)

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MMSE and driving

• The CMA Guidelines states Individuals showing a
  score of less than 24 on the MMSE are ineligible
  to hold a drivers license of any class pending
  complete neurological assessment.
• Patients scoring under 20 on the MMSE are
  considered unsafe to drive.

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Principles of Driving Assessment(Canadian
Consensus Conference on Dementia )

• While caring for patients with cognitive
  impairment, physicians should consider the risk
  associated with driving. Focused medical
  assessments (including specific details in the
  medical history and physical examination) are
  recommended in addition to the general medical
  evaluation.
• Physicians should be aware that driving
  difficulties may indicate other cognitive or
  functional problems that need to be addressed.
• Physicians should encourage patients with
  Alzheimers disease and their caregivers to plan
  early for eventual cessation of driving
  privileges and provide continuing support for
  those who lose their capacity to drive.

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Assessing Driving Capacity in Patients with
Dementia

• Although the diagnosis of dementia does not
  automatically mean the person must stop driving,
  it does mandate that the family physician
  evaluate driving safety.
• The Ontario Highway Traffic Act mandates that
  physicians shall report any person suffering
  from a medical condition that may make it
  dangerous for such person to operate a motor
  vehicle.

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Physicians Responsibilities

• Inform patient of opinion and document
• Reporting to licensing authorities
• Know provincial/territories laws
• Err on side of caution (especially mandatory)
• Report on findings/advise on course
• Specialized testing centre (if available)
• Responsibility of licensing authority to decide

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Driving Capacity Assessment is Multi-Factorial
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Driving Capacity Assessment is Multi-Factorial

• Driving Record
• Questions to Family and Person
• Driving Record (accidents, near misses,
• violations)
• Driving Circumstances time of day, weather,
• traffic conditions. If the person is self
  limiting driving may be flag
• Examine the car for damage

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Questions to Ask Person

• Have you noticed any changes in your driving
  spells or feeling less confident about driving?
  Do you think at present you are an unsafe driver?
• In the last year, have you had any accidents or
  near misses or tickets for traffic violations
  (driving too slowly / failing to stop)?
• Have you restricted your driving habits (driving
  less or only familiar routes, or avoiding driving
  at night, in bad weather, or on busy streets)?
• Have you ever become lost while driving or
  forgotten where you were going?
• Do other drivers honk at you or show irritation
  about your driving?

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Questions to Ask Family

• Do you or would you feel uncomfortable being a
  passenger when the person is driving?
• In the last year has the person had any accidents
  or near misses or tickets for traffic violations
  (driving too slowly, failure to stop)?
• Have you noticed the person self-restricting
  their driving habits (driving less or only
  familiar routes, or avoiding driving at night, in
  bad weather, or on busy streets)?
• Have you or others seen unsafe or abnormal
  driving behavior or are cues / directions needed
  from a copilot?
• Have there been occasions where the person has
  gotten lost or shown navigational confusion?

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Driving Capacity Assessment is Multi-Factorial

• Vision/Hearing
• Visual acuity / field of vision / hearing.
• Physical Examination
• Strength, tone, range of motion and coordination
  of upper and lower extremity
• Balance, Gait and Reaction time
• CVS BP and IHD

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Driving Capacity Assessment is Multi-Factorial

• Cognitive Factors
• Test response to situation (fire in kitchen)
• Draw intersecting pentagons / clock /
  3-dimensional cube
• Trails Test
• Presence of Dementia.
• If mild they may be considered safe to drive if
  other confounding factors not present

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Driving Capacity Assessment is Multi-Factorial

• Medications
• Benzodiazepines
• Antidepressants
• Opioid analgesics
• Hypoglycemics, insulin
• Antihistamines

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GENERAL APPROACH
(W Dalziel 2003)
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Driving Capacity Assessment is Multi-Factorial

• Functional Abilities in terms of Instrumental
  Activities of Daily Living
• Behavioral Issues e.g. aggression, impulsivity,
  delusions, hallucinations etc
• Other Medical Conditions especially IHD,
  arrhythmias, epilepsy, tremor, Parkinsons
  Disease, sleep apnea, and MSK