The Naturalistic Driving Observation for Assessing Elderly Drivers: Implementing a Contemporary Research Approach in Clinical Use

This study explored the naturalistic driving observation (NDO) (Vlahodimitrakou et al., 2013) in the context of fit-to drive assessments of elderly drivers, with a view to expand current driving assessment approaches. This is to permit occupational therapists (OT) to consider and incorporate an assessment method that is both structured, score-based and individualized for each driver. By utilizing this unique assessment, real-life driving performance is captured and reduction in test-related discomfort associated with the current gold standard test of driving ability, the standard on-road driving evaluation (SODE), is achieved. There is limited research comparing the two assessments (SODE and NDO).

STUDY OBJECTIVES: 1. To compare the NDO to the current gold standard, the SODE among community-dwelling older adults; 2. To explore the relationships between the two driving assessments, NDO and SODE and in-clinic assessments of driving-related skills and personal characteristics.

DESIGN: This study was a descriptive cross-sectional study. Sixty-one participants, all active drivers (driving at least once a week), 71.98±4.54 years old, most of them men (62.3%), participated.

METHOD: Participation involved completion of a comprehensive assessment battery including in-clinic assessments of driving-related skills and two on-road assessments: the SODE and the NDO. The NDO was utilized according to the CanDrive protocol (Vlahodimitrakou et al., 2013). Both driving assessments were scored using in-car video recordings of the assessment. Driving performance was scored by OTs utilizing the electronic Driver Observation Schedule (eDOS) (Koppel et al., 2012). Differences between the two driving assessments were examined using Wilcoxon signed-rank tests. Relationships between the two driving assessments and in-clinic assessments as well as participants’ characteristics were examined using Spearman’s Rho test. Mann-Whitney U test was utilized to compare differences in driving performance between groups defined by specific driver characteristics (e. g. differences between men and women).

RESULTS: Driving performance was significantly different between the two driving assessments, the NDO and the SODE. eDOS scores were significantly higher (better) on the SODE (Median=92.51, IQR=87.20-94.87) than NDO (Median=88, IQR=81.43-92.23) (Z=-3.90, p<.001). Driving performance in both the NDO and the SODE correlated with in-clinic assessments. Different significant correlations were found between specific driving errors to in-clinic assessment’s subtests or test items. The correlations found were low (ranged between rs=.29 to rs=.47). In general, better performance on in-clinic tests was related to better performance on the driving assessments. Driving performance scores on both driving assessments correlated to participants’ characteristics of gender and residential area, as well as to age, education, number of days driving per week, driving confidence, self-reported level of ‘active driver’ and perceived driving quality.

CONCLUSION: The NDO can constitute an appropriate method for assessing fitness-to-drive of elderly drivers. The NDO was found to correlate with the practiced gold standard (i.e. SODE) and proved to have advantages in assessing elderly drivers. This reflects a growing trend in the driving rehabilitation field. However, to date, policy stakeholders do not consider this method of assessment. OTs should take the lead in writing clear guidelines for deciding which method is best suited to assess the elderly driver that will lead to the best clinical decision of fit-to-drive.

References

Vlahodimitrakou, Z., Charlton, J. L., Langford, J., Koppel, S., Di Stefano, M., Macdonald, W., … & Marshall, S. (2013). Development and evaluation of a Driving Observation Schedule (DOS) to study everyday driving performance of older drivers. Accident Analysis and Prevention 61, 253– 260.

Koppel, S., Charlton, J. L., Langford, J., Di Stefano, M., Macdonald, W., Mazer, B., …Marshall, S. (2012, October). Findings from the Candrive/Ozcandrive Study: A preliminary analysis of the driving observation schedule (DOS) data Paper presented at the Candrive/Ozcandrive Symposium, Australian Road Safety Research, Policy and Education Conference, Wellington, New Zealand 4th-6th October, 2012.

Chen, Y. T., Gélinas, I. & Mazer, B. (2018). Determining Older Adults’ Fitness-to-Drive: Comparing the Standard On-road Driving Evaluation and the Naturalistic Driving Observation. Physical & Occupational Therapy in Geriatrics, 36, 90-106.