Date Presented 4/20/2018
Returning combat veterans are at increased risk for motor vehicle collisions, injuries, and deaths. This poster describes the steps in a program of research that are critical for conducting a clinical trial to assess the effectiveness of an occupational therapy driving intervention.
Primary Author and Speaker: Sherrilene Classen
Additional Authors and Speakers: Sandra Winter
BACKGROUND AND PURPOSE: Previous driving simulator studies (Classen et al., 2011; Hannold et al., 2013) indicated that combat veterans (N = 18) made significantly more speeding, adjustment-to-stimuli, and total number of driving errors compared with healthy control drivers (n = 18), leading the researchers to examine the benefit of an Occupational Therapy–Driving Intervention (OT–DI) in reducing driving errors in returning combat veterans. The participants in a single-subject design study completed a simulated drive during which seven driving errors were assessed. Next they underwent three 1-hr OT–DI sessions and a posttest on the driving simulator. The OT–DI sessions included (1) a self-appraisal of driving performance via coaching and identifying adaptive strategies to mitigate driving errors, (2) visual search skills training, and (3) use of adaptive strategies during a narrated drive. Participants’ overall driving errors decreased from 33 to 9 (Classen et al., 2014), and in a follow-up study combat veterans’ (N = 8) lane maintenance and total number of driving errors were reduced (p < .05). Despite limitations, these two studies suggested clinical utility and feasibility for a simulator-based OT–DI to reduce driving errors. The purpose of the current study was to determine the interim effect of an OT–DI versus a traffic safety education program (TSE).
METHOD: Ethics approval was obtained from the university’s institutional review board. Combat veterans were recruited via in-person visits at Veterans Administration settings and flyers and were enrolled in the study if they met inclusion and exclusion criteria. The power analysis suggested alpha = .05, beta = 20%, effect size = .40, and sample size = 60 to detect a statistically significant difference in total number of driving errors. The sample consisted of 26 (of 60) participants allocated via a computer-generated block (×6) randomization scheme to the intervention (OT–DI) or control (TSE) group.
After informed consent was obtained, driver rehabilitation specialists (DRSs) administered the baseline and posttests. Driving performance was assessed on a DriveSafety CDS-250 simulator (DriveSafety, Murray, UT). The intervention group (n = 13) received three OT–DI sessions delivered by a DRS. The control group (n = 13) received three 1-hr TSE sessions delivered by a traffic safety professional addressing (1) general traffic safety discussion, (2) rules and knowledge of the road, and (3) use of the simulator without any feedback from the traffic safety professional.
Immediately after Session 3, Posttest 1 occurred using the same (as baseline) standardized protocols. We used IBM SPSS Statistics Version 22 (IBM Corp., Armonk, NY) for data analyses via descriptive statistics, Shapiro–Wilk tests, and nonparametric Wilcoxon rank-sum tests.
RESULTS: No significant differences were found between the OT–DI and TSE groups at baseline. For the OT–DI group (baseline to Posttest 1), four driving errors (lane maintenance, speeding, vehicle position, signaling) and total number of driving errors were reduced (p < .0001). The TSE group had a reduction from baseline to Posttest 1 in adjustment-to-stimuli errors. When comparing the OT–DI group to the TSE group after Posttest 1, three driving errors (speeding, signaling, gap acceptance) and total number of driving errors were reduced (p = .01) for the OT–DI group. Results suggest that the OT–DI group benefited from the intervention to a greater extent than the control group benefited from the TSE.
CONCLUSION: Despite limitations (e.g., lack of blinding, driving simulator scenarios not randomized), these early findings support the effectiveness of the OT–DI, but caution must be exercised until the study and final analyses are completed (Classen et al., 2016).
The U.S. Department of Defense (Project No. W81XWH-11-1-0454) provided funding for this study.
References
Classen, S., Levy, C., Meyer, D., Bewernitz, M., Lanford, D. N., & Mann, W. C. (2011). Simulated driving performance of combat veterans with mild traumatic brain injury and posttraumatic stress disorder: A pilot study. American Journal of Occupational Therapy, 65, 419–427. https://doi.org/10.5014/ajot.2011.000893
Classen, S., Monahan, M., Canonizado, M., & Winter, S. (2014). Utility of an occupational therapy driving intervention for a combat veteran. American Journal of Occupational Therapy, 68, 405–411. https://doi.org/10.5014/ajot.2014.010041
Classen, S., Winter, S., Monahan, M., Yarney, A., Lutz, A. L., Platek, K., & Levy, C. (2016). Driving intervention for returning combat veterans: Interim analysis of a randomized controlled trial. OTJR: Occupation, Participation and Heath, 37, 62–71. https://doi.org/10.1177/1539449216675582
Hannold, E. M., Classen S., Winter S., Lanford, D. N., & Levy, C. E. (2013). Exploratory pilot study of driving perceptions among OIF/OEF veterans with mTBI and PTSD. Journal of Rehabilitation Research and Development, 50, 1315–1330. https://doi.org/10.1682/JRRD.2013.04.0084
