Using a database of 40 million people, a new detailed microsimulation has examined the future of Japan’s aging population up to 2043. It projects that more people will live longer and that overall years spent living with dementia will decrease.
Japanese restaurant. Image credit: Pxfuel, free license
However, the model highlighted the diversity of impacts on different segments of the population, as Japanese women with a less than high school education aged 75 and over may be disproportionately affected by both dementia and frailty. A better understanding of where health gaps exist can help inform public health planning to minimize future economic costs and support those most in need.
These bar charts show projected life expectancy for men and women aged 65 years in 2016 and 2043, with and without dementia, and my educational background. Image credit: 2022 The Lancet Public Health, Kasajima, et al. CC BY 4.0
Taking care of older members of society is a common concern worldwide. Japan is famous for its long-lived residents, the number of which continues to rise. In 2020, almost 30% of the Japanese population was aged 65 years or older, and this age group is not projected to peak until 2034. Caring for people with age-related ailments, such as dementia and frailty, poses a challenge to individuals and public health care systems.
Microsimulation models, which are computer models that can provide detailed analysis on an individual basis, are currently used to project future population health in some countries, such as the U.K. and the U.S. Professor Hideki Hashimoto and researchers at the University of Tokyo, along with researchers from Stanford University in the U.S., wanted to create a new microsimulation model for Japan, which would take into account more diverse conditions than had been considered before.
“We developed a new Japanese microsimulation model that accounts for 13 chronic conditions (including heart disease, stroke, diabetes, depression, and dependency), as well as frailty and dementia,” explained Hashimoto.“Using an ultra-large data system, we could ‘follow’ a virtual cohort of more than 40 million people aged 60 and over from 2016 to 2043.”
According to Hashimoto, projections of aging in Japan usually rely on the “average” status of older people and don’t consider the diversity of the population. “I believe that aging problems are a matter of health gaps throughout people’s lives,” he said. “Our projection brings attention to a widening health gap among older people. It highlighted that women with a less than high school education aged 75 or over are more likely to be affected.”
They identified where health gaps like this could be used to better inform public policy about health care and other influential aspects of life. “Japan’s case may suggest that improvement in educational attainment and population health could be a key to making a healthier and more manageable aging society,” said Hashimoto.
Positively, this study shows hope for a future where many people live longer and more healthy lives. “People might believe that an increase in cases of dementia is inescapable, given population aging. However, in this study, we found that in Japan, despite an aging population, the number of people with dementia is expected to decrease over the next two decades,” said Hashimoto. “Population aging does not necessarily mean an increase of social burden for care, but it does bring a diversity of problems that require careful study and science-based policy attention, to close the health gap.”
Source: University of Tokyo