Everyone’s driving changes as they age. But for some people, subtle differences emerge in how they control a vehicle, which scientists say are associated with the early stages of Alzheimer’s disease.
In an experiment to find out whether these driving differences can be detected using Global Positioning System-based (GPS) location-tracking devices, a group of over-65s in Washington State in the US agreed to have their driving closely monitored for one year.
What the researchers wanted to find out was whether just studying the driving habits of this group alone could reveal the start of the disease – without the need for invasive or expensive medical procedures.
After 365 days accumulating the information, they are confident that it could.
Among the 139 people involved in the study, medical tests had already shown around half of them had very early or “preclinical” Alzheimer’s disease. The other half did not. Analysis of their driving revealed detectable differences between the two groups.
Specifically, those with preclinical Alzheimer’s tended to drive more slowly, make abrupt changes, travel less at night, and logged fewer miles overall, for example. They also visited a smaller variety of destinations when driving, sticking to slightly more confined routes.
“How people move within their daily environments, ranging from the places they visit to how they drive, can tell us a lot about their health,” says Sayeh Bayat, a PhD candidate at the University of Toronto, who led the study.
GPS trackers fitted to the participants’ cars revealed these movements, and when they occurred, in detail.
The researchers running the study had previously split their participants into those with preclinical Alzheimer’s disease, and those without, using medical tests such as spinal fluid tests and positron emission tomography (PET) scans.
But using the results of the driving data, they were able to design a model that could forecast someone’s likelihood of having preclinical Alzheimer’s using merely their age and their GPS driving data. It proved to be 86% accurate.
“Using these very few indicators… you can really, with very high confidence, identify whether a person has preclinical Alzheimer’s disease or not,” says Ms Bayat.
The model was more accurate still (90%) when it also added in the results of a genetic test for Alzheimer’s known as apolipoprotein E (APOE) genotyping that indicates whether you may have an inherited risk for the disease. (Although it’s worth bearing in mind this group only represents some of the people who eventually go on to develop Alzheimer’s).
But the prediction based on age and driving alone was almost as precise.
Larger, randomised studies are needed to show a definitive link between the detected driving behaviours and preclinical Alzheimer’s disease.
However, the potential game changer here is that this could be a low-cost way of detecting the condition at an earlier stage, potentially supporting treatment. But it also raises the question of whether older people would want their behaviour to be tracked so closely, even if there were health benefits.
The fact that people’s driving behaviour changes when they have Alzheimer’s is well documented. The US National Institute on Aging says family members might eventually notice that their loved one is taking longer to complete a simple trip, has been driving more erratically, or gets muddled over which pedal is which, for example.