Evaluation of Two Assessment Tools in Predicting Driving Ability of Senior Drivers

Abstract

To evaluate Motor Free Visual Perceptual Test (MVPT) and Clock Drawing Task (clock test) as quick assessment tools in predicting driving capability of senior drivers for an on-road driving test. Senior drivers (> or = 55 yrs) referred for evaluation and recommendation for license renewal were given the MVPT, clock test, and an on-road driving test. Receiving operating characteristic (ROC) analysis and stepwise multivariate logistic regression (SMLR) were used to develop a probability model to differentiate between capable and incapable senior drivers. Data for 232 seniors who had completed all written tests and the on-road driving test were analyzed. Of the 232 seniors, 131 (56%) were classified as capable and 101 (44%) as incapable drivers on the road test. Mean scores for capable and incapable drivers were MVPT 32.0 +/- 4.0 vs. 28.4 +/- 4.6 and mean clock test score 3.5 +/- 0.8 vs. 2.7 +/- 1.2, and mean processing time was 7.1 + 6.5 vs. 10.6 + 5.5. The means of the three measurements were significantly different between the two groups (P value <0.001). ROC curve analysis revealed an optimal cut point of > or = 32 for MVPT score with 60% sensitivity and 83% specificity. The optimal cut point for clock test scores is > or = 3 with 70% sensitivity and 65% specificity. The optimal cut point for processing times is < or = 6.27 secs with 60% sensitivity and 80% specificity. SMLR showed that the most significant predictor of seniors' driving capabilities are the MVPT test scores and clock test scores. MVPT and clock test tools are significant predictors of driving capability on an on-road driving test.