You can take advantage of the comprehensive Clinical Assessment of Driving Related Skills (CADReS), a toolbox of evidence-based practical, office-based assessment tools to screen for impairment in the key areas of vision, cognition, and motor/sensory function as they relate to driving. This comprehensive toolbox is available in the Clinician’s Guide to Assessing and Counseling Older Drivers, 4th Edition, published by the American Geriatric Society (referred to as the Clinician’s Guide), Chapter 3, p. 28-47.) The following links provide a step-by-step approach summarizing how you can integrate safe driving into ongoing office visits and patient encounters.
Step 1: Interview and Driving History
You can assess whether older adults who are currently driving are functionally able to continue safe driving using the Modified Driving Habits Questionnaire (MDHQ), a shorter version of the original Driving Habits Questionnaire (DHQ). This questionnaire comprises 30 questions and focuses on current driving history, accidents, citations, driving space, and other factors that have been precise and accurate measures for detecting driving habits in the self-driving elderly population. (Soon). Both the patient and caregiver can offer their perceptions of current driving practices. The modified version is available in Appendix C of the Clinician’s Guide, p. 228.
You can also ask the patient about Activities of Daily Livings (ADLs), basic tasks such as feeding, dressing, grooming, and bathing, as well as Instrumental Activities of Daily Living (IADL), more complex tasks that include driving, using public transportation, financial management, housekeeping, using the telephone. You would ask: “Do you have difficulty or require assistance with any of the following?” A checklist of both types of activities and scoring guidelines are available from the University of Florida Institute on Aging at Activities of Daily Living (ADLs).
Age-related declines may lead to deterioration of either ADLs or IADLs. Driving uses the same underlying functions (e.g., visual processing, executive functioning, memory, processing speed) as other IADLs, and any restrictions in IADLs may warrant further evaluation of driving.
Step 2: Vision Screening
Driving demands strong visual acuity and skills. At the same time, vision is the most relevant age-related impairment for driving; approximately 80% to 90% of information related to traffic is received visually. Visual factors, along with cognition, explain 83% to 95% of “age-related variance in the capacity to drive safely.” (Dattoma, p. 462).
General Visual Acuity commonly declines with age due to the increased changes of the eyes and incidence of conditions such as cataracts, glaucoma, diabetic retinopathy, and age-related macular degeneration (ARMD). These conditions can be easily measured in office settings, using tools such as the Snellen chart. Near visual acuity also can be measured by the Rosenbaum pocket chart.
Cataracts are a major concern associated with vision and driving, since their gradual development results in a slow change in vision that the older adult may not recognize. Cataract removal can effectively improve driving safety. Near visual acuity can be assessed by the Rosenbaum pocket chart, or other method to confirm:
- Visual Field is measured by confrontation testing (having the patient look directly at clinician’s eye or nose to test each quadrant in a patient’s visual field and having them count the number of fingers shown). Each eye should be tested separately. If deficits are noted, formal visual field perimetry may be indicated, which may require referral to an ophthalmologist. Most problems related to visual field are the result of glaucoma, detached retina. and stroke. Loss of peripheral vision may cause problems in noticing traffic signs or cars, vehicles in adjacent lanes, or street crossings. (Clinician’s Guide, pp 33-34) and Kiersten)).
- Contrast sensitivity, measured by the Pelli Robson contrast sensitivity chart, decreases with aging and is often an issue during dawn and dusk hours in foggy conditions or during storms. (Clinician’s Guide, p. 50). A driver should be able to recognize objects at reasonable distances in a short time. As evidenced by many studies, contrast sensitivity can help predict a driver’s ability to see an oncoming target or stationary object at the first possible moment. (Ginsburg, p. 36).
Step 3: Cognition Evaluation
Driving requires timely cognitive, as well as visual, processing to make appropriate decisions in a complex environment; skills in these areas are vital for safe driving. Cognition changes can decrease functions needed to solve problems and cope with challenging traffic situations.
Dementia deserves special emphasis because it presents a significant challenge to driving safety. As the disease progresses, individuals will ultimately lose the ability to drive safely. In addition, older adults with dementia often lack insight into their deficits and, therefore, may be more likely than drivers with visual or motor deficits (who tend to self-restrict their driving to accommodate their declining abilities) to drive even when it is unsafe. In this case, it becomes the responsibility of family members and other caregivers to protect the safety of older adult drivers with dementia by enforcing driving cessation when this becomes necessary.
The Dementia Screening Interview is an eight-item caregiver questionnaire that differentiates between dementia and normal aging, with preliminary data indicating that it can be used with other tools to decide whether an aging adult is fit to drive.
The Impact of Cognitive Impairments on Driver Safety provides more detailed information about assessment of cognitive skills in older adults related to driving and offers resources that address dementia. This fact sheet describes tests for measuring cognition that are available in the Appendix of the Clinician's Guide, pp. 233-238. These screening tools include the Montreal Cognitive Assessment, the Trail-Making Tests A/B, the Snellgrove Maze test, and the clock-drawing test that help to assess visuospatial ability, executive function, attention and psychomotor coordination, memory, and insight into one’s own driving abilities (Hill, p. 1583).
You can take several steps after conducting the in-office tests described in the fact sheet on cognition:
- Review the older adult’s medications and assess for potential adverse effects of the medications on cognition.
- Ask the older adult and caregivers about the onset of cognitive decline relative to new medications or changes in dosage.
- Treat the underlying disorder and/or adjust medications. Refer the older adult for more extensive examination to a neurologist, psychiatrist, or neuropsychologist.
- Recommend a comprehensive driving evaluation performed by a driving rehabilitation specialist to assess the older adult’s performance in the actual driving task. An initial comprehensive on-road assessment with retesting at regular intervals is particularly useful for those with progressive dementing illnesses.
Step 4: Motor/Sensory Function Assessment
Aging causes decreases in muscle strength, reaction time, and mobility, particularly of the neck, shoulder, and wrists—all of which can affect driving ability in addition to increasing risk of falls and other complications. These declines restrict the field of view in traffic or the ability to control the steering wheel. Tasks like fastening a seatbelt or modulating the pressure needed on the brake pedal may be impossible for some aging adults to complete if they lack motor and somatosensory abilities.
In an office setting, you can conduct three simple tests that measure overall lower extremity strength, coordination, and proprioception in a function task.
- Rapid Pace Walk test measures ambulatory function, measures lower limb strength, endurance, and balance. The patient walks ten feet and returns, using their normal assistive gait device, if necessary. Those adults requiring more than nine seconds are considered at increased risk for motor vehicle crashes. The clinician can review causes of the slower pace and consider interventions, such as physical therapy.
- Get Up and Go, a complementary test to Rapid Pace Walk that evaluates balance and gait requires patients to stand up from a chair, walk ten feet, turn around, return, and sit down again. The clinician can detect hesitancy, slowness, staggering, stumbling and other abnormal movements of the trunk and upper and lower extremities. A score of three or below on a five-point scale, with one being normal usually indicates a need for referral and treatment. (Dattoma, p. 462). This test has been closely linked with falls, which have been associated with poor driving outcomes. (Scott).
- Functional Strength and Range of Motion can be tested in-office, with the clinician asking the patient to perform the motions listed below bilaterally:
- Neck rotation: “Look over your shoulder like you’re backing up or parking. Now do the same thing for the other side.”
- Shoulder and elbow flexion: “Pretend you’re holding a steering wheel. Now pretend to make a wide right turn, then a wide left turn.”
- Finger curl: “Make a fist with both of your hands.”
- Ankle plantar flexion: “Pretend you’re stepping on the gas pedal. Now do the same for the other foot.”
- Ankle dorsiflexion: “Point your toes toward your head”
- A clinician scores this test by evaluating the motion as either “within functional limits” or “not within functional limits.” The latter score indicates that range of motion is done with excessive hesitation, pain, or very limited range of motion. (Primary care providers Guide, p. 43)
A more comprehensive driver’s skills assessment of motor abilities is available from the University of Missouri Geriatric Toolkit.
After reviewing the results of the tests to measure motor skills, you may offer these recommendations, along with required prescriptions and any restrictions:
- Begin or maintain a physical activity program that includes cardiovascular exercise, strengthening exercise, stretching, and balance exercises, with the approval of a physician. Activities and information for older adults can be downloaded at the National Institute of Health (NIH) Institute on Aging website.
- Make an appointment with a physical therapist or occupational therapist to improve strength, flexibility, and range of motion.
- Learn about vehicle adaptation that may compensate for limited range of motion or other physical deficits to improve driving safety, such as hand controls, bigger mirrors, or adjustable foot pedals. Patients can be referred to ChORUS for additional information on vehicle safety features and adaptation and to CarFit, an educational program that offers older drivers an opportunity to check how well their current vehicle “fits” them.
- Contact a local driving rehabilitation specialist (DRS) who can provide a comprehensive assessment, help determine a driver’s medical fitness to drive, and recommend training or vehicle adaptations to assist drivers. Medical Professionals may be able to locate a DRS through the Nationwide Database of Driving Evaluation Specialists, developed by the American Occupational Therapy Association (AOTA).
Step 5: Review of Medications
Older adults often take multiple medications concurrently, with approximately 36% using five or more prescription medications. In addition, older adults often take multiple central nervous system (CNS)-active medications with 25% taking two or more classes. A major cause of motor vehicle accidents and crashes that result in injury and fatality is impaired driving that can be due to certain classes of medication. Medications associated with increased crash risk are referred to as potential driving-impaired (PDI) medications. These medications include those that impact the CNS, blood glucose levels, blood pressure, vision, or that pose risks to safe driving, for example, by affecting a driver’s cognition, judgment, and reaction time. Often, patients who take over-the-counter or prescription medications are not aware of the negative impact these medications can have on safe driving. (Ivers and White)
The most common PDI medications are:
- Antiparkinsonian agents
- Benzodiazepines and nonbenzodiazepine hypnotics
- Muscle relaxants
- Narcotic analgesics (CG, p. 146)
The Clinician’s Guide, on page 147, offers Table 9.13 (Need to add link and table) that summarizes the common PDI medications and the specific adverse effects (cognitive, visual, and motor abilities) that may contribute to impaired driving. For more detailed information about each class of medications, you can download a PowerPoint presentation and additional text provided by a medical expert on older drivers and medication.
Other substances, including alcohol, marijuana, cocaine and amphetamines are also causes of impaired driving which can increase the risk of crashes. Marijuana use, for example, has increased among older drivers and a combination of the cognitive change and sedation effects can have deleterious consequences for older drivers. (Choi)
PDI effects include:
- Sedation or drowsiness
- Blurred vision
- Mood changes
- Loss of coordination (ataxia) (Lococo and Tyree; Marottoli)
Another resource that can be used as a starting point in reviewing an older patient’s medications is the American Geriatric Society (AGS)2019 Beers Criteria © Update of Potentially Inappropriate Medication Use (PIMS).
The 2019 AGS Beers Criteria® include 30 individual criteria of medications or medication classes to be avoided in older adults and 16 criteria specific to more than 40 medications or medication classes that should be used with caution or avoided in certain diseases or conditions. These criteria serve as a valuable tool and can be part of a comprehensive approach to medication use in older adults. Used in conjunction with other tools and management strategies for improving medication safety and effectiveness, the criteria can be a relevant resource to ensure safe driving for older adults.
- Medical Professionals can take several steps to ensure driving safety among patients who are taking medications, particularly PIMS.
- Consider risks and benefits of all medications taken by a patient in terms of driver safety, taking into consideration the patient’s existing regimen of prescription and non-prescription drugs.
- Try to prescribe non-impairing medications and the safest drug/medication class when possible.
- Introduce new medications at the lowest dosages; modify any changes in dosage with recommendations to the patient to refrain from driving until the patient believes that no adverse events will occur.
- If medications are introduced while the older adult is hospitalized, the impact of adverse effects on driving performance should be discussed before discharge.
- Document discussions with patient/caregiver in the medical record about potential risk to driving safety, since clinicians, who have a duty to warn, can be held accountable for medication adverse effects to patients while driving. (Marotolli Medscape slides)
You can also use MedScape’s Older Driver Safety Training site. This site hosts CME/CE-associated learning activities to facilitate the clinicians’ ability to assess for patients’ driving challenges and risks. The activities will also discuss driving safety with potentially at-risk drivers (those older and/or drug-impaired) and their families. Strategies are provided to enable clinicians to modify risk, when appropriate, and to address the difficult issue of what to do if their patient is thought to be a safety risk to self and others because they continue to drive. To obtain credit you first should register on Medscape then take the free courses at Driver Safety: The Clinician’s Driver Safety: The Clinician’s ConnectionConnection