Effect of Navigation Problems, Assessment Location, and a Practice Test on Driving Assessment Performance for People with Alzheimer's Disease.

BACKGROUND

People with Alzheimer's disease may be required to undertake clinical and on-road assessments to determine fitness to drive. The manner in which on-road assessments are conducted with drivers who do and do not have navigational problems may affect the outcome.

OBJECTIVES

Investigate the effect of 1) navigational difficulties, 2) location of assessment (un/familiar area) and assessment order, and 3) undertaking a second assessment (practice), on passing an on-road driving assessment.

METHODS

Forty-three drivers undertook an Occupational Therapy-Driver Assessment Off Road Assessment (OT-DORA) Battery which included the Drive Home Maze Test (DHMT). Participants with/without a history of navigational problems were randomly allocated into three groups: 1) Unfamiliar/then familiar area assessment; 2) Unfamiliar/unfamiliar; 3) familiar/unfamiliar. An on-road assessment protocol was used including over 100 expected behaviors at nominated points along the directed route. For familiar area assessments, the driver self-navigated from their home to shops and services. A pass/fail decision was made for each assessment.

RESULTS

A generalized linear mixed effects model showed neither location, nor practice affected passing the on-road assessment. Participants with navigational problems were six times less likely to pass regardless of route familiarity and direction method, and the DHMT was a significant negative predictor of passing.

CONCLUSION

Drivers with Alzheimer's disease who have navigational problems and are slow to complete the DHMT are unlikely to pass an on-road assessment. However, navigation and maze completion skills may be a proxy for an underlying cognitive skill underpinning driving performance.