SURVIVAL OF CENTENARIANS IN JAPAN.

The objective of the study was to explore the survival trends of centenarians in Japan. A cohort of centenarians born between 1881 and 1900 was analysed based on national census data, and the average life expectancy at 100 years of age, risk of death and maximum age were estimated. An analysis of covariance and a Cox regression analysis were performed to explore the factors associated with life expectancy and risk of death. The death rates in centenarians tended to decrease with birth year, and the average life expectancy from the age of 100 slightly increased at a rate of 0.013 years (95% CI: 0.007-0.019) by birth year in men and 0.026 in women. Women had a longer life expectancy than men, with a difference of 0.174 years (95% CI: 0.071-0.277) at birth year 1881 and increasing by 0.013 years per year thereafter. The risk of death in both sexes decreased significantly by birth year over the course of the period analysed, and the risk of death in men was 1.16 (95% CI: 1.14-1.19) times that of women. In women, death rates at every age significantly decreased with birth year over the course of the period analysed until age 104. However, this trend did not hold true for ages 105 and older. The average life expectancy of centenarians at the age of 100 in Japan increased by birth year in the 1881-1900 birth cohort. In addition, Japanese centenarians had the lowest death rates among several countries.