Date Presented 3/31/2017
Motor vehicle collisions are a leading cause of deaths for combat veterans, and effective occupational therapy driving interventions (OT–DIs) are needed. We conducted an analysis of an efficacy trial comparing an OT–DI with traffic safety education and demonstrated a reduction in driving errors for the OT–DI group.
Primary Author and Speaker: Sherrilene Classen
Additional Authors and Speakers: Sandra Winter
Contributing Authors: Charles Levy, Abraham Yarney, Miriam Monahan
PURPOSE: Returning combat veterans (CVs) face risks, including motor vehicle crash (MVC), as they integrate into their communities. Risk of MVC rises significantly after each deployment and is a leading cause of CV death and injury. Crashes are preventable, compelling efforts toward an injury prevention intervention. It is essential to safely and accurately assess CV driving errors and to provide strategies addressing battlemind driving (i.e., defensive combat-related techniques; Hannold et al., 2014) and effects of polytrauma (i.e., two or more combat-related injuries such as traumatic brain injury, posttraumatic stress disorder, or orthopedic injury). Therefore, we studied the efficacy of a simulator-based occupational therapy driving intervention (OT–DI; three sessions focused on visual search training and driver fitness strategies) versus Traffic Safety Education (TSE; three sessions on personal choices and defensive driving). We hypothesized that the OT–DI would significantly reduce the total number of driving errors compared with TSE.
DESIGN: This study was an interim analysis of an unblinded parallel arm randomized controlled design. The study was powered (alpha = .05, beta = 20%, effect size = .40) to detect significant differences in the total number of driving errors.
METHOD: Approval was obtained from the university’s institutional review board, the Department of Veterans Affairs, and the Department of Defense. Participants were CVs who had polytrauma, a valid driver’s license, and potential to follow safety recommendations. CVs who were medically advised not to drive, had psychiatric or physical conditions, or had complex medication use impacting driving were excluded.
Following group randomization, participants underwent baseline testing using a standardized intake protocol; a clinical battery of visual, cognitive, and motor tests; and a driving error assessment (number and type) on a DriveSafety CDS-250 simulator (DriveSafety, Murray, UT; Classen et al., 2011, 2014, 2015, in press). The Simulator Sickness Questionnaire (SSQ) was completed pre and post all drives. CVs underwent a 2- to 3-min acclimation drive to comfortably and confidently conduct basic driving maneuvers. Next, they drove a 6-min residential/suburban drive starting in an unmarked two-lane road at 25 mph. This scenario had traffic, parked cars, roadside trashcans, pedestrians, and roadkill. The driver encountered four-way stop intersections and transitions to a rural two-lane road at 45 mph and then to a busy commercial four-lane road at 35 mph. Three scripted events occurred, requiring driver vigilance to avoid adverse traffic events. Next, they drove the 10-min city/highway drive starting in an urban area with multilane and narrow city streets and moderate traffic. The drive proceeded to a freeway with roadside debris, a disabled vehicle, and a tow truck. Again, three scripted, but different, events occurred, requiring driver vigilance to avoid a crash.
Following three sessions of the OT–DI or TSE as described above, we conducted posttesting. Using IBM SPSS Statistics Version 22, and for each group, we conducted a Wilcoxon rank-sum analysis to detect the difference in number of driving errors at baseline and Posttest 1 and a paired-sample t test to determine the driving error difference scores of the means for baseline and Posttest 1.
RESULTS: The CV (N = 26) by OT–DI (n = 13) and TSE groups (n = 13) were all male and mostly White, educated past high school, and married. SSQ scores were not significant. The OT–DI group’s total driving errors were reduced when comparing baseline scores to Posttest 1 (p < .0001) and when comparing their driving errors to the TSE group at Posttest 1 (p = .01).
CONCLUSION AND IMPACT STATEMENT: Our findings provide early support for the OT–DI’s efficacy and set the stage for a future effectiveness study addressing CV driver fitness and prevention of needless driving-related injury and death in this population.
