Older automobile drivers : medical aspects

This study aims to investigate the effectiveness of medical screening of older drivers, and to identify risk factors for road traffic accidents among older drivers. The effectiveness of the medical examination in license renewal procedure was evaluated by comparing accident statistics in Sweden where no compulsory medical check-up is needed, and Finland where the license expires at age 70 and needs a medical check-up to be renewed. The results state no evidence for any traffic safety effect of the license renewal procedure in Finland compared to Sweden. Nor did the medical examination of drivers convicted for crashes uncover any differences compared to controls. However, tests of memory and visuospatial ability indicated that cognitive impairment was more frequent in the crash group compared to controls. In the test of visual acuity with Snellen's 'E', which carries a greater cognitive load than letters, those drivers convicted of crashes scored lower than controls. The neuropathological assessment disclosed evidence of Alzheimer's disease in more than half of the deceased drivers. Blood samples from 23 percent of the male drivers 75+ revealed that, at the time of the fatal crash, they had in their blood drugs known to have an impact on cognitive functions. To conclude, cognitive impairment seems to be a very important risk factor for older drivers. The cognitive impairment is often not great enough to be detected during an ordinary medical examination. Details of cognitive function should be included in the examination of older license applicants. The physician must also be made aware of drug influence on cognitive functions and the subsequent increase in accident risk when using such drugs.