Intersection Rules Subtest Timing as a Predictor of DriveSafe DriveAware Outcomes: A Pilot Study

ImportanceIntersection Rules Subtest timing is a potential predictor of the DriveSafe outcome score in DriveSafe DriveAware (DSDA) assessment.ObjectiveTo examine whether Intersection Rules completion time is associated with DriveSafe outcome within the DSDA assessment.DesignRetrospective, observational pilot study using secondary data.SettingAustralian metropolitan fitness-to-drive clinic.ParticipantsOf 169 participants (median age = 80; 61.5% male), 104 categorised into non-pass group of DriveSafe subtest formed 'cases', whilst 65 who passed were 'controls'.Outcomes and MeasuresPrimary predictor: Intersection Rules Subtest completion time in seconds. Primary outcome: DriveSafe subtest outcome, categorised as pass/non-pass. Relationships analysed using logistic regression and receiver operating characteristic (ROC) curve analysis.ResultsLonger Intersection Rules Subtest time significantly predicted lower DriveSafe subtest outcome (non-pass) scores, with each additional 60 s increasing odds of failure by 93.7% (odds ratio [OR] = 1.94, 95% confidence interval [CI] [1.40, 2.68], p < .001). A ROC curve analysis revealed an area under the curve of 0.73 (95% CI: [.654, .807]). An optimal cut-off of 213.5 s showed high specificity (86.2%) (95% CI: [75.3, 93.5]) but modest sensitivity (48.1%) (95% CI: [38.2, 58.1]) for a non-pass result.Conclusions and RelevanceIntersection Rules Subtest completion time was associated with DriveSafe outcome in this pilot study. The current findings support future study of this timing metric, which may have potential as a clinical decision-support indicator, a 'Detect and Pause' step, after prospective validation and DSDA protocol sequence modification.