Validation of a Short Cognitive Screening Battery to Predict Fitness-to-DRIVE in Individuals with Multiple Sclerosis

Background: Determining the fitness-to-drive of individuals with Multiple Sclerosis (MS) usually involves the administration of 15 or more physical, visual, and cognitive tests. In the United States, the process typically lasts longer than 3 hours and costs more than $500. However, not all individuals with MS need to undergo the time-consuming and expensive process. The fitness-to-drive of some can be determined with a very good degree of accuracy based on performance on a few but highly predictive tests.

Objectives: In a previous study, we identified five cognitive tests that together predicted the outcome of a comprehensive driving evaluation of 44 individuals with multiple sclerosis (age = 46 ± 11 years, 84% females) with 91% accuracy, 70% sensitivity, and 97% specificity. The five tests include the Stroop Color test, the Direction, Compass, and Road Sign Recognition tests of the Stroke Driver Screening Assessment battery, and the Speed of Processing sub-test of the Useful Field of View test. In this study, we sought to validate the predictive accuracy of the five tests in a different cohort of individuals with multiple sclerosis.

Methods: Sixty-three participants (age = 49 ± 9 years, 89% females) were administered the five cognitive tests. Participants were also administered a standardized practical on-road driving test. Performance on the road test was judged by completing a 16-item checklist of very important driving skills. A raw score of 45 or more out of 50 maximum points was classified as “pass” and below 45 as “fail”. Performance on the five cognitive tests was used to predict the pass/fail outcome of the on-road test.

Results: All five variables each had significant association with the on-road test raw score. The five tests together explained 44% of the variance of the pass/fail classification. Participants’ “pass” or “fail” performance on the road test was predicted with 83% accuracy, 67% sensitivity, and 85% specificity.

Conclusions: The short battery of five tests, which together can be completed in < 1 hour and should cost less than $250, appears to be a valid predictor of fitness-to-drive of individuals with multiple sclerosis (83% accuracy) and more accurate at predicting individuals who will pass an on-road evaluation (85% specificity) than those who will fail (67% sensitivity).