Driving assessment for maintaining mobility and safety in drivers with dementia

The proportion of older people in the world is increasing and consequently the number of older drivers is also on the rise. Older people commonly depend upon private motor vehicles for their transport needs and so assessment of older drivers with cognitive impairment is becoming increasingly important. We have reviewed the literature on driving assessment in people with dementia for two reasons. First, we wished to see if assessment helped people with dementia and good driving skills continue driving. Second, we wished to discover whether assessment was useful in preventing road traffic accidents.

Although many authors have studied the motor skills, neuropsychological performance and driving behaviour of drivers with dementia, we found no study that randomised drivers to evaluate these outcomes prospectively following assessment. This highlights the need for caution in applying the literature on driving assessment to clinical settings as no benefit has yet been prospectively demonstrated. It also indicates the need for prospective evaluation of new and existing models of driver assessment to best preserve transport mobility and minimise road traffic accidents.

Authors' conclusions: 

In an area with considerable public health impact for drivers with dementia and other road users, the available literature fails to demonstrate the benefit of driver assessment for either preserving transport mobility or reducing motor vehicle accidents. Driving legislation and recommendations from medical practitioners requires further research that addresses these outcomes in order to provide the best outcomes for both drivers with dementia and the general public.

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Background: 

Demographic changes are leading to an increase in the number of older drivers: as dementia is an age-related disease, there is also an increase in the numbers of drivers with dementia. Dementia can impact on both the mobility and safety of drivers, and the impact of formal assessment of driving is unknown in terms of either mobility or safety. Those involved in assessment of older drivers need to be aware of the evidence of positive and negative effects of driving assessment. Cognitive tests are felt by some authors to have poor face and construct validity for assessing driving performance; extrapolating from values in one large-scale prospective cohort study, the cognitive test that most strongly predicted future crashes would, if used as a screening tool, potentially prevent six crashes per 1000 people over 65 years of age screened, but at the price of stopping the driving of 121 people who would not have had a crash.

Objectives: 

Primary objectives:
1. to assess whether driving assessment facilitates continued driving in people with dementia;
2. to assess whether driving assessment reduces accidents in people with dementia.

Secondary objective:
1. to assess the quality of research on assessment of drivers with dementia.

Search strategy: 

ALOIS, the Cochrane Dementia Group's Specialized Register was searched on 13 September 2012 using the terms: driving or driver* or "motor vehicle*" or "car accident*" or "traffic accident*" or automobile* or traffic. This register contains records from major healthcare databases, ongoing trial databases and grey literature sources and is updated regularly.

Selection criteria: 

We sought randomised controlled trials prospectively evaluating drivers with dementia for outcomes such as transport mobility, driving cessation or motor vehicle accidents following driving assessment.

Data collection and analysis: 

Each review author retrieved studies and assessed for primary and secondary outcomes, study design and study quality.

Main results: 

No studies were found that met the inclusion criteria. A description and discussion of the driving literature relating to assessment of drivers with dementia relating to the primary objectives is presented.