Self-regulatory practices of drivers with Parkinson's disease: Accuracy of patient reports

Background: Studies suggest that drivers with Parkinson's disease (PD) are more likely than controls to restrict their exposure and avoid challenging situations possibly to compensate for declining abilities; however it is questionable whether patient reports should be taken at face value. To address this issue, this study examined agreement between self-reported and actual driving practices in drivers with and without PD. Methods: Two electronic devices (one with GPS) were installed in the vehicles of 26 drivers with PD (mean age 71.5 +/- 6.8, 77% men) and 20 controls (mean age 70.6 +/- 7.9, 80% men) for two weeks. Participants completed a questionnaire on usual driving patterns, scales on Situational Driving Frequency (SDF) and Avoidance (SDA), the MoCA and an interview. Results: Self-estimates of distance driven (km) over the two weeks were inaccurate in both groups; however the tendency to under-estimate was more pronounced in PD drivers. Drivers with PD reported more self-restrictions (higher SDA scores, p<.01; lower SDF scores, p<.05), yet drove more at night, in bad weather, in rush hour and on highways than they reported. Drivers with PD had significantly lower MoCA scores overall (p<.01) and on the memory subtest (p<.05), however, MoCA scores were not correlated with self-reported restrictions, or actual driving distance in either group. Conclusions: These findings indicate that patient reports of driving behavior should not be taken at face value by researchers or clinicians. Patients with PD may be more likely than drivers in general to have problems with recall and possibly less awareness of their driving practices. (C) 2012 Elsevier Ltd. All rights reserved.