Abstract
PURPOSE: Mild cognitive impairment and gender can impact different aspects of driving performance and behaviour in older drivers. However, there is little evidence on how these may affect naturalistic speeding behaviour. Therefore, the aim of this study was to examine the relationship between speeding events and cognitive status for older male and female drivers. PARTICIPANTS AND METHODS: A naturalistic driving study collected objective driving information over a two-week period using an in-vehicle monitoring device from 36 older drivers with suspected mild cognitive impairment and 35 older drivers without cognitive impairment. The outcome of interest examined was the number of speeding events, defined as travelling 5+ km/h over the posted speed limit for at least a minute. RESULTS: The majority of participants (n=58, 81.69%) did not have a speeding event during the two-week monitoring period. Twenty-three speeding events were recorded among seven drivers with suspected mild cognitive impairment and six drivers without cognitive impairment. The majority of speeding events (82.61%) were by older male drivers and occurred in 60km/h and 70km/h speed zones. The results of the two negative binomial regression models found that in older male drivers, suspected mild cognitive impairment (IRR=7.45, 95% CI=1.53-36.15, p=0.01) was associated with a significantly higher rate of speeding events, while increasing age was associated with a lower rate of speeding events (IRR=0.80, 95% CI=0.64-1.00, p=0.04). For older female drivers, there were no factors significantly associated with the rate of speeding events. CONCLUSION: While the overall number of speeding events were infrequent, suspected mild cognitive impairment was associated with a significant increase in the rate of speeding events for older male drivers, but not for older female drivers. Speeding interventions and injury prevention policy strategies may need to be targeted differently for male and female drivers with mild cognitive impairment.