• May 1, 2009 Ruth Lilly Auditorium, Riley Hospital

OBJECTIVE: The aim of this research study was to determine the relationship between simple and choice reaction time and driving performance in older adults. This can be used to establish if reaction time measurements are a significant component of evaluations and assessments used to determine driving performance.

METHODS: The design is a retrospective analysis from a previously completed cross sectional research study. During the initial study, participants completed a behind-the-wheel assessment along with a battery of physiological and cognitive tasks. A Driving Performance Score was computed in order to quantify driving ability and a Global Rating Score was assigned based on driving behaviors and performance. As part of this study, statistical analyses were run to measure the correlation between driving performance and simple and choice reaction time. Simple and choice reaction time's ability to predict driving performance as part of a predictive model was also assessed.

RESULTS: The participants' mean age was 74.8 years (SD = 6.5) and consisted of more males (58.1%) than females. The majority of the participants were Caucasian (90.5%) and education level was distributed evenly among higher education. This study has determined both simple and choice reaction time measurements to be statistically significant components when determining driving performance. A Pearson correlation revealed r = -0.393, p = 0.001 when comparing simple reaction time with the Driving Performance Score and r = -.276, p = 0.023 when comparing the score with choice reaction time. A Pearson correlation comparing simple reaction time and choice reaction time with the Global Rating Score revealed r = -0.363, p = 0.001 and r = -0.343, p = 0.003 respectively. The addition of simple and choice reaction time independently to a previously established model predicting the Driving Performance Score yielded R2 values of .462 and .426 respectively. When simple and choice reaction times were added to the predictive model of the Global Rating Score, R2 values of .432 for simple reaction time and .354 for choice reaction time were yielded.

CONCLUSION: The inclusion of simple reaction time to the predictive model increased the strength of association between driving performance and independent variables of the model. There is a statistically significant correlation between both simple and choice reaction time and driving performance however, simple reaction time produced a stronger relationship with driving performance. Based on these results and the ease of data collection within the clinic, the inclusion of simple reaction time to a battery of driving assessments would be beneficial to occupational therapist when predicting driving performance.