Behind the wheel: a randomised controlled trial evaluating a safe transport program for older drivers

Abstract

Purpose: To determine if a one-on-one safe transport program can change driving behavior in a group of older drivers living in the community who rely heavily on driving for transport.

Methods: We adapted the Knowledge Enhances Your Safety (KEYS®) program for the Australian context and evaluated the effectiveness of the program using a randomised controlled trial involving 380 drivers aged 75 years and older, residing in the suburban outskirts of Sydney. The primary outcome was total weekly driving (km) collected via an in-vehicle data logger, with GPS receiver, hard-wired to the vehicle which transmitted time-stamped data on location every 20 seconds during vehicle operation over mobile telecommunications network. One sub-group analysis was pre-specified based on cut-off scores from the DriveSafe/DriveAware tool which is a computerized assessment of visual attention. Secondary outcomes included stage of behavior change with regards to self-regulation of driving and uptake of alternative transport at 12 months. We used generalized estimating equations to model the impact of the safe transport program on driving exposure adjusting for repeated, weekly measures over 12 months.

Results: We recruited 380 participants (230 men, 150 women) with average age 80±4 years and average weekly mileage of 140±167 km; 366/380 (96%) completed the 12-month study and 362/380 (95%) vehicles were instrumented. The safe transport program was delivered to 183/190 (96%) of those drivers allocated to the intervention group. While there was no difference in weekly mileage (between group difference: -6km, p=0.52), there was a reduction in driving in the subgroup of drivers (n=78) with higher DriveSafe/DriveAware scores (between group difference -43km, p=0.04). Those with lower scores had no difference in mileage (2km, p=0.82). 10/366 (3%) ceased driving and the intervention group were more engaged in self-regulation of driving (stage of behavior change: between group difference 1.3, p=0.04). At 12 months there was similar usage of alternative forms of transport (total monthly trips 7.0±12.8 vs 5.7±9.7, p=0.31).

Conclusions: This evaluation shows that an individualized safe transport program promoted behavior change but did not translate into a significant difference in weekly mileage. Drivers with higher function were more able to reduce their driving exposure and this may confer a safety benefit to drivers in this age group.