Abstract
The SIMARD (Screen for the Identification of Cognitively Impaired Medically At-Risk Drivers) is a cognitive screening tool used identify unsafe drivers, however, there is controversy regarding its clinical effectiveness. The purpose was to examine whether 1) the SIMARD correlates with other clinical tests; and 2) to determine the SIMARD’s sensitivity and specificity for predicting pass/fail on the road test. Data were collected from two driving assessment centers in Ontario and Saskatchewan, respectively from 2012 to 2018. Data on 385 clients were collected including their demographics, clinical test scores (SIMARD, Montreal Cognitive Assessment [MoCA], Trails A & B, Useful Field of View [UFOV]) and on-road pass/fail outcomes. The average age of clients was 69 ± 14.9 years; 73% were male; 42% failed the road test. On the SIMARD, the mean score was 49.7 ± 22.8 (range of 2 to 114) with clients being classified as low risk (18%), requiring further testing (61%) and high risk (21%). The SIMARD mean score was significantly correlated with age (r=.57, p<.001), Trails A (r=.39, p<.001), Trails B (r=.59, p<.001) and the MoCA (r=.65, p<.001). A logistic regression with only the SIMARD found the test to be predictive of pass/fail outcomes on the road test (-2 Log Likelihood = 174.56; Nagelkerke R = .247) but there was a large number of misclassifications. When the SIMARD was combined with other clinical tests, the SIMARD was not a significant predictor of pass/fail outcomes on the road test. The SIMARD should not be used as a stand-alone driver screening tool.