Objective:

Investigate prevalence of real-world dyadic driving as a longitudinal predictor of cognitive function in urban and rural dwellers with mild cognitive impairment (MCI) or Alzheimer’s disease (AD). 

Background:

Research on older drivers at risk for cognitive decline due to MCI has focused on individuals. Cognitive decline affects driver performance, exposure, and agency. As disease progresses, a “co-pilot” (family member or friend) may accompany the driver, creating a verifiable social dyad, and a potential real-world social biomarker of the natural history and progression of disease. 

Design/Methods:

35 participants (mean age=76.9; male=24, female=11; MCI=31, AD=4) completed demographic questionnaires (including rurality, indexed by home ZIP code). A composite score, derived from neuropsychological tests spanning five cognitive domains, indexed cognition at study start (baseline) and one year later. Unobtrusive video-electronic systems, installed in each driver’s own vehicle (for 3 months at baseline), captured real-world solo and dyadic driving (percentage of drives with a passenger seat confederate, confirmed by video analysts).

Results:

We analyzed 9,553 videos across all participants. Pearson correlational analyses showed a curvilinear relationship between dyadic driving and cognitive function at baseline (p=0.11) and one year later (p=0.06). These relationships were significant after controlling for driver age and sex (ps<0.03). Moderation analyses showed an effect of driver home ZIP code (p<0.10); lower cognitive scores were associated with increased dyadic driving for urban, not rural, drivers.

Conclusions: