Characteristics of fatal traffic accidents among drivers aged 50 years or older with special reference to drivers with neurodegenerative disease or brain infarction.

OBJECTIVES: While fatal accident risk increases with age, neurodegenerative diseases and brain infarctions may further impair driving. However, detailed information on accident circumstances among drivers with these conditions remains limited. This study investigated characteristics of fatal traffic accidents among drivers aged 50 or older using Finnish medico-legal data. METHODS: This register-based study utilized medico-legal autopsy records of drivers who deceased in traffic accidents between 2016 and 2023. From the dataset (n = 445), three groups were distinguished: cases with neurodegenerative disease (n = 18), cases with a history of brain infarction (n = 29), and cases with no neurological conditions (n = 380). Medical history, circumstantial characteristics, weather and temporal variables, and causes of death were collected from the medico-legal documents. Cases with neurodegenerative diseases and brain infarction were compared to cases with no neurological conditions. RESULTS: Drivers with neurodegenerative disease or brain infarction were significantly older than drivers with no neurological conditions (medians 79 and 76 vs. 66 years) and had a higher burden of cardiovascular diseases. Head-on collisions accounted for 50.0% of accidents in the neurodegenerative group, and accidents involving heavy vehicles were only observed in the group with no neurological conditions. Across all groups, clear weather, dry road surface, and daylight were the most common weather conditions. CONCLUSIONS: Darkness and challenging weather conditions did not appear to be key characteristics of fatal accidents in either the neurodegenerative disease group or the brain infarction group. The observed prevalence of lifetime neurodegenerative diagnoses appeared lower than previously reported, suggesting that undiagnosed neurological conditions may have been present in our dataset, possibly attenuating group differences.