Aged drivers with Motoric cognitive risk syndrome and subjective memory concerns more prone to collisions: JAMA

New research found that old Japanese drivers having Motoric cognitive risk syndrome (MCR) or subjective memory concerns (SMC) had higher odds of car collisions and near-miss traffic accidents due to cognitive decline caused by aging. This is despite excluding the collisions caused by the driver's fault. 

The study was published in the journal JAMA Network Open on August 25, 2023. 

Aging causes perceptual and cognitive declines in various sensory systems like vision, hearing and vibration detection, attention, and speed of processing and responding. These are necessary for driver's safety. Slow gait and subjective memory concerns (SMC) are symptoms of motoric cognitive risk syndrome (MCR), which has been linked to slower processing speeds and executive function as well as a higher chance of dementia or other disabilities. There is limited data on the association between MCR assessment and the risk of car collisions. Hence, researchers from the National Center for Geriatrics and Gerontology, Obu, Japan conducted a study To examine the association between MCR assessment findings and car collisions among older drivers in Japan. 

By using data from a community-based cohort study, the National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes, conducted in Japan from 2015 to 2018, a cross-sectional study was carried out on community-dwelling older adults aged at least 65 years. MCR was defined as having subjective memory concerns (SMC) and slow gait, based on which participants were classified into 4 groups: no SMC or slow gait, only SMC, only slow gait, and MCR. 

All the participants were questioned about their experience of car collisions during the last 2 years and any near-miss traffic incidents during the previous year through face-to-face interviews. The odds of experiencing a collision or near-miss traffic incident were assessed using logistic regression. 

Key findings: 

• Among a total of 12,475 participants, the mean (SD) age was 72.6 (5.2) years, and 7093 (56.9%) were male.
• When compared to the other groups, the group with only SMC and the group with MCR showed a higher proportion of both car collisions and near-miss traffic incidents.
• As per the logistic regression analysis, only SMC and MCR groups had increased odds of car collisions and near-miss traffic incidents after adjusting for confounding factors.
• Significant associations were still seen after stratifying MCR assessments by objective cognitive impairment. 
• In the only slow gait group, objective cognitive impairment was associated with increased odds of car collisions. 

Thus, older adults in Japan had higher odds of car collisions and near-miss traffic incidents due to SMC or MCR. 

Further reading: Kurita S, Doi T, Harada K, et al. Motoric Cognitive Risk Syndrome and Traffic Incidents in Older Drivers in Japan. JAMA Netw Open. 2023;6(8):e2330475. doi:10.1001/jamanetworkopen.2023.30475