Forgetfulness and diminishing cognitive abilities are undesirable yet integral aspects of advancing dementia. Nevertheless, another potentially threatening consequence of the disease is patients getting lost and being unable to find their home. A new study has found the reason behind why and what leads to them getting lost.
According to researchers from the University of East Anglia, individuals afflicted with dementia tend to go missing more often in areas where the network of roads is dense, disordered, and complicated. "People with dementia getting lost or going missing is a problem worldwide. Around 70 percent of people with dementia may go missing at least once, with some at risk of going missing multiple times," said Prof. Michael Hornberger, lead author of the study.
Inability to Remember
Dementia is an irreversible and progressive decline in memory, thinking and ability to perform simple everyday tasks. Advanced form of it, the Alzheimer's disease is the most common cause behind the onset of the condition affecting around 60 to 70 percent of patients.
According to the World Health Organization (WHO), approximately 50 million people across the world have dementia. Other areas that are affected by the condition include calculation, comprehension language, learning capacity, judgment and orientation. One of the first signs of the severity of the syndrome is gradual incapacitation activities such as being able to navigate or being unable to remember names, routes, and other rudimentary information.
"Unfortunately, the first event when people with dementia go missing comes completely out of the blue, when doing such routine activities as going for a walk with the dog or getting the newspaper from the local shop," pointed out Prof. Hornberger.
Link between Dementia and Road Networks
For the study, the team analyzed 210 'missing person' police reports about people with dementia in Norfolk County, England for over three years. Then they compared every case to the network of roads nearby. They sought to glean if the design of the road networks has an association with people with dementia who went missing.
"We know that people with dementia have difficulty navigating so we wanted to see whether there was a relationship between people going missing and the outdoor environment they went missing from," explained Vaisakh Puthusseryppady, co-author of the study.
The authors had a particular interest in the layouts of the roads as they play a crucial role in the way people navigate. They sought to evaluate the complexity of the road network, the complexity of road intersections and the level orderliness of the overall layout of the road network.
Why Do People Go Missing?
Through the analysis, the authors learnt that there was indeed a connection between people with dementia getting lost and the layout of the roads. "We found that the higher the density of road intersections, the more complicated the road intersections are, and the less ordered or less grid-like the overall road network layout, the greater the risk for people with dementia to get lost," said Puthusseryppady.
It is known knowledge the complex decision-making is affected by dementia. The scientists inferred that every road intersection serves as a point where a person needs to make critical navigation decisions. With the increase in the number of intersections, the higher complexity of these intersections, and the more disorganized the overall road network is, the difficulty for dementia patients becomes compounded. "This is because these factors can make it more likely for people with dementia to make an error and make a wrong turn, causing them to get lost and go missing," said Puthusseryppady.
He added that, "We hope that by identifying these environmental risk factors, our findings can potentially help identify or predict areas where people with dementia may be at higher risk of going missing from - and contribute to the development of safeguarding guidelines to prevent them from going missing in future."