Neuropsychological Tests and Measurement of Comorbidity in Predicting Driving Competence among Memory Clinic Patients

Objective: Visuospatial, executive function, and attention abilities have previously been identified as predictors of driving competence, however specific neuropsychological tests that accurately predict driving outcomes have yet to be clearly defined. In addition, little is known about the impact of medical comorbidity on fitness to drive. The objectives of this study are to determine which neuropsychological tests predict driving competence and to elucidate the contribution of medical comorbidity to driving risk. Method: Neuropsychological test raw scores (NPT), driving assessment scores (DA), and medical histories were collected retrospectively from a total of 138 patients who had undergone routine clinical evaluation and the computer-based DriveABLE assessment over a 5-year period. Results: Poorer NPT performance significantly predicted higher DA score (R 2 = 0.530, p < 0.05) indicating a greater probability of failing the road test. The combination of Coding (B = -0.49, p = 0.03), Visual Reproduction Delayed Recall (B = -2.00, p < 0.001), and Boston Naming Test 60-item (B = -0.45, p = 0.08) raw scores was significantly predictive of DA (R 2 = 0.71, F(3, 38) = 12.54, p < 0.05; adjusted R 2 = 0.46). Medical comorbidity did not offer additional predictive value. Conclusions: These results suggest that performance on traditional neuropsychological tests can provide additional information regarding the patient's ability to drive.