Table of Contents

2.2.7 Multiple medical conditions and age-related change

Where a vehicle driver has multiple conditions or a condition that affects multiple body systems, there may be an additive or a compounding detrimental effect on driving abilities, for example, in:

  • congenital disabilities such as cerebral palsy, spina bifida and various syndromes
  • multiple trauma causing orthopaedic and neurological injuries as well as psychiatric sequelae
  • multi-system diseases such as diabetes, connective tissue disease and HIV
  • dual diagnoses involving psychiatric illness and drug or alcohol addiction
  • ageing-related changes in motor, cognitive and sensory abilities together with degenerative disease.

Although these medical standards are designed principally around individual conditions, clinical judgement is needed to integrate and consider the effects on safe driving of any medical conditions and disabilities that a patient may present with. For example, glaucoma may cause a slight loss of peripheral vision. If combined with cervical spondylosis and low insight, there is likely to be a substantial reduction in the driver’s visual fields and possibly their perceptual abilities, thus increasing the risks of missing important visual information when driving.

Advanced age, in itself, is not a barrier to driving, and functional ability rather than chronological age should be the criterion used in assessing the fitness to drive of older people. Age-related physical and mental changes vary greatly between individuals but will eventually affect the ability to drive safely. Professional judgement must determine what is acceptable decline (compensated by the patient’s long experience and self-imposed limitations on when and where they drive) and what is irreversible, hazardous deterioration in driving-related skills that requires reporting to the licensing authority. This may require careful consideration and specialist referral. Note that some driver licensing authorities require medical examination or assessment of drivers beyond a specified age. These requirements vary between jurisdictions and may be viewed in Appendix 1: Regulatory requirements for driver testing.

As all possible combinations of disabilities are too numerous to detail here, the examining health professional should follow general principles when assessing these patients:

  • The driving task. First, consider the ergonomics of the driving task as shown in Figure 1. How might the various impairments (sensory, cognitive and musculoskeletal), disabilities and general fitness levels impact on the functions required to complete driving-related tasks?
  • Clinical assessment. The key considerations are:
    • sensory (in particular visual acuity and visual fields but also cutaneous, muscle and joint sensation)
    • motor function (including joint movements, strength and coordination)
    • cognition (including attention, concentration, presence of hallucinations and delusions, insight, judgement, memory, problem-solving skills, thought processing and visuospatial skills)
    • risk of sudden incapacity.

It may be necessary for the health professional to consider medical standards for each condition. However, it is insufficient simply to apply the medical standards contained in this publication for each condition separately, as a driver may have several minor impairments that alone may not affect driving but when taken together may make risks associated with driving unacceptable. It will therefore be necessary to integrate all clinical information, bearing in mind the additive or compounding effect of each condition on the overall capacity of the patient to control the vehicle, and to act and react in an appropriate and timely way to emergent traffic and road conditions.

  • General functional assessment. Consider to what extent the person is currently able to function in regard to domestic or occupational requirements and what compensatory or coping strategies may have been developed. Information gained from relatives or carers is also likely to be important in this regard. Individuals may be likely to cope better with congenital or slow-onset conditions compared with traumatic or rapidly developing conditions. A referral for an assessment by a generalist occupational therapist may be appropriate. It should request an evaluation of overall functioning (personal, mobility, community and work activities) and general capacity for driving (this assessment may be available under the Medicare ‘Care Plan’ for people with multiple disabilities as well as for those turning 75 years).
  • Practical driver assessment. A practical driver assessment may be required to assess the impact of injury, illness or the ageing process on driving skills including judgement, decision-making skills, observation and vehicle handling. The assessment may also be helpful in determining the need for vehicle modification to assist drivers with musculoskeletal and other disabilities (refer to section 2.3.1 Practical driver assessments).This is particularly relevant to those applying for, or seeking to maintain, a commercial vehicle licence. A referral to a Driver Assessor Occupational Therapist (DAOT) may be required for a comprehensive driving assessment and determination of suitability for vehicle modifications and/or driving rehabilitation/retraining (refer to Appendix 10: Specialist driver assessors).
  • Capacity to learn to drive. Young people with multiple disabilities may seek the opportunity to gain a driver licence. In order to ensure they receive informed advice and reasonable opportunities for training, it is helpful if they are trained by a driving instructor with experience in the area of teaching drivers with disabilities. An initial assessment with an occupational therapist specialised in driver evaluation may help to identify the need for adaptive devices, vehicle modifications or special driving techniques.
In light of the information gathered from the above, the health professional may advise the patient regarding their fitness to drive and provide advice to the driver licensing authority. The key question is: Is there a likelihood the person will be unable to control the vehicle and act or react appropriately to the driving environment in a safe, consistent and timely manner? The threshold tolerance for multiple conditions is much less for commercial vehicle drivers where there is the potential for more time on the road and more severe consequences in the event of a crash.

Where one or more conditions is progressive, it may be important to reduce driving exposure and ensure ongoing monitoring of the patient (refer to section 2.2.5 Progressive conditions). Conditional licences that may limit the driver (e.g. no night driving) or place requirements on the vehicle (e.g. automatic transmission only) are an option in these circumstances (refer to section 4.4 Conditional licences).The requirement for periodic reviews can be included as recommendations on driver licences. This is also important for drivers with conditions likely to be associated with future reductions in insight and self-regulation. If lack of insight may become an issue in the future, it is important to advise the patient to report the condition(s) to the driver licensing authority. Where lack of insight already appears to impair self-assessment and judgement, public safety interests should prevail, and the health professional should report the matter directly to the driver licensing authority and, if appropriate, seek the support of the patient’s family members.

For patient information and resources refer to section 2.3.4 Information and assistance for drivers.