DOCTORS ON DRIVING
 
Diabetes & Driving Disabilities & Driving Vision & Driving
Dementia & Driving Snoring & Driving Old Age & Driving
Heart Diseases & Driving Epilepsy & Driving Driver Checkup
 

Old Age and Driving

Should old patients drive?
 

Older drivers are involved in more fatal car crashes per miles driven than any other age group except teenagers. Drivers over the age of 75 years also have more traffic violations and nonfatal collisions than younger drivers. Two of the most common violations, failure to yield the right of way and failure to obey a traffic sign, often lead to accidents at intersections where situations require a quick response, full peripheral vision, and interaction with other drivers.

Do all patients with old age not fit to drive?
 

Despite a moderate decline in mental, motor, optic, and auditory functions with aging, many older people drive safely. Driving performance is usually impaired only after a considerable loss of function since most driving patterns are learned and become second nature. No one wants to use chronological age as the sole indicator of driving ability, but it is difficult to otherwise determine whether an older person can drive safely.

What happens during old age?
 

In addition to the normal changes in vision, psychomotor ability, and cognitive status with aging, older people are more likely to have medical conditions that can affect driving performance.

Which old patients take precautions?
 

A history of falls in the past one to two years; The presence of visual and cognitive deficits; A prior history of motor vehicle crashes; Current use of medications such as tricyclic antidepressants and benzodiazepines. On the other hand drugs like Beta-blockers may reduce performance anxiety and tremor, thereby strengthening vehicle control in some older people. A past or current history of ischemic heart disease, cerebrovascular disease, movement disorders, diabetes mellitus, epilepsy, sleep disorders, and arthritis should be evaluated during the primary care examination. Based upon a recent history of these conditions, the clinician should recommend that patients of any age stop driving for some period of time until recovery is assured and the baseline level of functioning has returned. The occurrence of an unforeseeable, disabling event can cause serious driving consequences with several of these conditions.

What are the physiological changes during old age?
 

Medications, alcohol, and other substances. An older person received an average of 17 to 20 prescription drugs per year. The physiologic changes associated with aging affect drug absorption, distribution, and renal excretion.

Which drugs are not safe in the elderly?
  A careful history of prescription, over-the-counter, and herbal medications is important in all seniors. Medications with effects on the central nervous system, such as benzodiazepines, antihistamines, anticholinergics, and some tricyclic antidepressants, can be harmful alone and especially in combination. More than one-third of all benzodiazepine prescriptions are written for people ages 60 and older. The traffic accident risk increases by nearly 50 percent in the first week after starting benzodiazepine therapy.

 Why use of alcohol is more harmful in senior citizens?
  The use of alcohol and other substances is hazardous for drivers of any age. However, the physiologic changes of aging such as a decrease in lean body mass and increase in adipose tissue, as well as the potential for multiple drug interactions, make this a significant issue for older drivers.

How does a family decide about the safety of driving by a old person?
 

For all patients aged 65 and older, specific questions about driving should be included in the primary care history:
How did the older patient get to the primary care visit?
How often and under what circumstances does he/she drive?
Any traffic violations, accidents, or close calls within the past six months, year, two years?
Any episodes of getting lost while driving?
Does the older person feel comfortable and want to continue driving?
Physical examination - The areas of the physical examination most closely related to driving safety are mobility and functional status, visual attention, and cognitive status.

How to evaluate?
 

Mobility - Aging precipitates changes in muscle strength, reaction time, and mobility, particularly of the neck, shoulder, and wrist. Decreased muscle strength can significantly impact driving ability. Grip strength appears to decline after age 75, although exercise can help to avoid significant loss. Restrictions in neck, shoulder, and wrist movement, often caused by rheumatologic conditions, can restrict the field of view in traffic situations, as well as the ability to control the steering wheel. Mobility issues relevant to driving can be assessed in several ways during the primary care visit.

What are the screening tests?
 

Evaluate range of motion of the neck, shoulders, and wrists. Evaluate balance and gait with the Get Up and Go Test. In this brief and practical test, the older patient is asked to rise from a chair, walk 10 feet, turn around, walk back, and then sit down in the chair. The test is timed and usually takes 15 seconds. The clinician should observe the use of the arms or hands to assist the rise from the chair, the height and length of the steps, use of the arms when walking, balance and ease of the turnaround (the most unstable portion of the gait), and how easily the older patient sits down again. There are no established norms to score the test, but observation of these aspects of the older patient's performance during the Get Up and Go Test can provide important information on the risk for falls and driving problems.

What is functional reach test?
  It is another test for balance and fall risk that is easily administered in the primary care office. A yardstick is mounted to the wall. The patient stands close to the wall with feet flat on the floor and raises one arm parallel to the yardstick, with the arm at 90 degrees of shoulder flexion, the elbow extended, and the hand fisted. The patient is asked to keep the fist in line with the yardstick and lean forward as far as possible, without taking a step or falling forward. As the patient leans forward, the fist moves along the yardstick. If the starting and ending point of the fist is less than six inches, the patient is at a high risk of falling within the next 6 months.

What is grip test?
  Measuring grip strength with a dynamometer can be useful for older drivers who have had a stroke. The general rule is that 35 pounds of strength in the dominant hand is necessary for safe driving.

What happens to the vision with age?
 

The majority of visual impairment and blindness in older people is caused by age-related macular degeneration, glaucoma, cataracts, and diabetic retinopathy. Age-related changes in vision that can affect driving include decreases in central visual acuity and peripheral vision, diminished ability to accommodate, and heightened sensitivity to glare. Over age 50, the total horizontal peripheral visual field declines from 170 degrees to 140 degrees. Drivers with deficits in peripheral vision have twice as many collisions as those with normal vision. Many older adults avoid driving at dusk and twilight because of these changes.

What are vision testing requirements?
  Visual acuity and peripheral vision are evaluated in most states as part of the driver's license renewal process. Retesting visual acuity between the renewal periods is required only if there has been a driving incident. The most common acceptable requirements are a visual acuity of 20/40 in the better eye and 120 degrees of horizontal peripheral vision.

 What is the roughs test for the vision?
 

The standard required for driving is the ability to read a car number plate at 20 metres. Any change in vision may mean driving should be stopped until an optician has been consulted. Any loss of vision should be reported.                                 Loss of vision in one eye does not prevent driving, provided that the person has adjusted to it.
Glaucoma, colour blindness and cataracts do not mean you cannot drive, provided you meet the standard required.

What is near vision testing?
 

In the primary care setting, the most effective measures for detecting significant age-related eye problems are the history, visual acuity testing, and fundoscopy. In addition to past and current medical history and medications, the specific visual history should include a family history of eye disease and the presence of current visual symptoms. Distance visual acuity can be evaluated with the Snellen chart. Near visual acuity can be measured with the Rosenbaum pocket vision screening card or by having the older patient read a newspaper or magazine held 14 inches (at arm's length) from the eyes; generally newspaper type is equivalent to 20/40 on the Snellen near visual acuity chart. Fundoscopic evaluation of the optic disc, macula, and red reflex will reveal macular degeneration, diabetic changes, glaucoma and cataracts.

How is hearing impairment associated with driving accidents?
 

Hearing impairment is the third most prevalent chronic health condition in older adults. Significant hearing loss can affect driving performance and safety. Screening for hearing loss should begin with the history, such as difficulties hearing the television and telephone or understanding speech in a crowded room, and otoscopic inspection for cerumen impaction. The whisper test can be used as a brief screening tool to determine whether there is a difference in hearing in each ear and whether referral for formal audiologic examination is necessary. In this test, one ear is occluded and the older patient is asked to repeat the words or numbers whispered softly by the clinician standing one to two feet away, usually to the back of the patient. The whispered words or numbers used for the test should be those with equally accented syllables, such as baseball or twenty-two.

How to check for the mental functions?
 

Mental status testing correlates better with driving performance than a specific diagnosis of dementia. The Mini-Mental State Exam (MMSE), a brief test of orientation, memory, and attention, can be used in the office setting to evaluate mental status. The maximum score on the MMSE is 30. Older drivers with scores of 23 to 25 out of 30 have more serious driving problems than normal controls. Drivers scoring 23 or less should be advised to stop driving until more formal neuropsychological testing is completed.

What is pentagon test?
 

The total score on the MMSE is not as predictive of adverse driving events as performance on one feature of the test, copying the pentagon/hexagon figure [10,26-28]. In this portion of the MMSE, the clinician draws two intersecting pentagon or hexagon figures, each side about one inch, and then asks the older patient to copy the figures exactly. The test is scored as a "pass" if all the sides and angles of the figures are preserved and if the sides intersect. Any tremor or rotation of the figures is ignored.

What are the warning signals for unsafe driving in patients with dementia?
 

The Alzheimer's Association Web site ( www.alz.org ) is an excellent resource for clinicians, patients, and families on many aspects of Alzheimer's dementia, including driving. They describe the warning signs of unsafe driving, such as forgetting how to locate familiar places, failure to obey traffic signals, making slow or poor decisions, driving at an inappropriate speed, and becoming angry and confused while driving. These signs can be useful for the older adult and the family to identify the unsafe older driver.

 
 
   

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