Aims: Our purpose was to identify cognitive tools associated with unsafe driving among elderly drivers of varying cognitive levels.
Methods: Twenty drivers with early-stage dementia of the Alzheimer type and 56 nondemented drivers aged 65-85 were recruited. Various cognitive processes were measured and unsafe driving was evaluated during an in-traffic road test with 3 different indicators and a composite indicator.
Results: The Wechsler Digit Symbol Substitution Test score was the best cognitive measure to detect unsafe drivers using the composite driving indicator.
Conclusion: The Digit Symbol Substitution Test may be used by physicians for the evaluation and follow-up of older patients, with or without Alzheimer-type dementia, as a screening tool of unsafe driving.