Self-Reported Driving Behaviours and the Relationship With Sleepiness in Subjective Cognitive Decline and Mild Cognitive Impairment

Background Driving promotes independence in older adults, yet age-related changes in cognition and sleepiness may reduce driver safety. We examined associations between sleepiness and driving in older adults with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). Methods A cross-sectional/observational study of older drivers (60-80 years), classified as cognitively healthy (n = 21), SCD (n = 26), or MCI (n = 13), completing the Manchester Driver Behaviour Questionnaire (DBQ), and a 2-week driving diary including the Sleepiness Symptoms Questionnaire (SSQ). Results For DBQ, MCI drivers reported 2.26x more driving lapses (eg, memory/attention failures) than healthy, while SCD reported 2.54x more driving violations than MCI. For diaries, SCD drivers reported 7.51x more inattention events than healthy, and higher SSQ ( P = .002). Higher SSQ was associated with increased inattention events for SCD and MCI groups ( P ≤ .018). Conclusion Sleepiness impacts poorer driving outcomes in SCD and MCI, providing an intervention opportunity to support continued driving.