The SIMARD-MD is not an Effective Driver Screening Tool for Determining Fitness-To-Drive

Background Studies have reported poor sensitivity and specificity of the Screen for the Identification of Cognitively Impaired Medically At-Risk Drivers, a modification of the DemTech (SIMARD-MD) to screen for drivers with cognitive impairment. The purpose of this study was to determine whether the SIMARD-MD can accurately predict pass/fail on a road test in drivers with cognitive impairment (CI) and healthy drivers. Methods Data from drivers with CI were collected from two comprehensive driving assessment centres (n=86) and compared with healthy drivers (n=30). All participants completed demographic measures, clinical measures, and a road rest (pass/fail). Analyses consisted of correlations between the SIMARD-MD and the other clinical measures, and a receiver-operating-characteristic (ROC) curve to determine the predictive ability of the SIMARD-MD. Results All healthy drivers passed the road test compared with 44.2% of the CI sample. On the SIMARD-MD, the CI sample scored significantly worse than healthy drivers (p<.001). The ROC curve showed the SIMARD-MD, regardless of any cut-point, misclassified a large number of CI individuals (AUC=.692; 95% CI = 0.578, 0.806). Conclusions Given the high level of misclassification, the SIMARD-MD should not be used with either healthy drivers or those with cognitive impairment for making decisions about driving.

Automated summary

The study found that the SIMARD-MD had poor predictive accuracy for determining pass/fail on a road test for both drivers with cognitive impairment (CI) and healthy drivers. Healthy drivers had a higher pass rate on the road test compared to the CI sample. The ROC curve indicated that the SIMARD-MD misclassified a significant number of CI individuals.