A new detailed microsimulation, using a database of 40 million people, 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.

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.

Better understanding where health gaps like this exist can help inform public health planning, to minimize future economic costs and support those most in need.

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.

“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 requires careful study and science-based policy attention, to close the health gap.”