The following is a summary of “Predicting Driving Cessation Among Cognitively Normal Older Drivers: The Role of Alzheimer Disease Biomarkers and Clinical Assessments,” published in the May 2024 issue of Neurology by Babulal, et al.

Clinicians need to understand why older adults stop driving due to the growing number of Americans with Alzheimer’s disease (AD) and an aging population since driving is essential for independence and mobility.

Researchers conducted a retrospective study of a well-characterized community cohort to identify factors that predict when older adults give up driving to cognitively normal.

They enrolled participants aged 65 or older from two projects. Weekly drivers had normal cognition (Clinical Dementia Rating [CDR] = 0) at baseline. Annual assessments, including β-amyloid PET imaging and CSF (Aβ₄₂, total tau [t-Tau], and phosphorylated tau [p-Tau]) collection every 2–3 years were conducted. The primary outcome was time from baseline to driving cessation, considering death as a competing risk. The association between time to cessation and biomarkers, adjusted for covariates, was examined using the Fine and Gray subdistribution hazard model.

The results showed 283 participants, and the average follow-up was 5.62 years. Driving cessation (8%) correlated with older age, female gender, progression to symptomatic AD (Clinical Dementia Rating [CDR] ≥0.5), and lower performance on a preclinical AD’s cognitive composite (PACC) score. Aβ positron emission tomography (PET) imaging didn’t independently forecast driving cessation. Still, cerebrospinal fluid (CSF) biomarkers, particularly t-Tau/Aβ₄₂ (HR 2.82, 95% CI 1.23–6.44, P=0.014) and p-Tau/Aβ₄₂ (HR 2.91, 95% CI 1.28–6.59, P=0.012) ratios, were independent predictors in a basic model adjusting for age, education, and gender. However, in the comprehensive model, progression to cognitive decline based on CDR and PACC score in each model related to a higher likelihood of driving cessation, while AD biomarkers didn’t reach statistical significance.

Investigators concluded that female sex, worsening dementia rating scores (CDR), and poorer cognitive performance in clinic tests were all strong predictors of future driving cessation.

Source: neurology.org/doi/10.1212/WNL.0000000000209426