A randomised controlled trial to determine the effect of assessment location and number of assessments on driving performance of people with dementia

Background An Occupational Therapy fitness-to-drive assessment may be required to determine if drivers in the early stages of dementia can continue to drive. Such assessments could be better tailored for clients with dementia if we had research evidence to support the location of assessment (open or local area), method (self directed or directed) and whether repeat testing is required (opportunity to undertake a second test), or which combination of these factors is best for drivers with, and without navigational difficulties.This study aimed to determine the effect of location of assessment (open or local area) and practice (undertaking more than one assessment) on pass or fail outcome for drivers both with, and without navigational problems. Methods 43 clients participated in a controlled trial in which the ordering and location of on-road driving tests have been randomised. Client driving assessment outcomes were recorded as pass, conditional or fail. Data were analysed using a generalized linear mixed effects model. Results The opportunity to have a second test (practice) had no effect on the probability of passing the on-road test (p= .514). 80% of drivers without navigational problems passed a local route self directed test, in comparison to 36% of drivers with navigational problems passing the same type of on-road assessment, reflecting this group's difficulty with independent navigation. 63% of people without navigational problems passed an open route test, where directions are provided, compared to 45% of drivers with navigational problems passing this type of on road assessment. Drivers with navigational problems were less likely to pass the on-road test than those without navigational problems (p= .032). Conclusions The difference in driver assessment performance is due to the characteristics of the driver, and not practice. Furthermore, whether the client undertakes a local area self directed test or an open route test (when instructions are given) is not pivotal to the outcome, but rather, whether the client has navigational problems or not. These findings will influence referral criteria for driver assessments, and the need to thoroughly assess navigational skills during driver assessment, for people with dementia.