What evidence is there to support on-road driving assessments?

Answer: A recent Cochrane review (Martin et al., 2009) indicates that there is currently no randomized control trial evidence to support the use of formalized driving assessments (ie assessments that include an on-road component) for the maintenance of mobility or safety in drivers with dementia. This conclusion was made due to lack of RCT trials evaluating the effect of on-road testing on MVC risk. Of course, there are ethical challenges to designing a study in which half of participants failing on-road assessment are randomized to continue driving, in order to evaluate the predictive validity of on-road assessments.