Trends in disability-free life expectancy in Japan, 1995-2004

Background: In Japan, life expectancy at birth is currently the highest in the world. However, recent trends in disability-free life expectancy in Japan have not been examined. Methods: We used data from Japanese national surveys for the period 1995-2004. These surveys included information on activity status measured by common self-reported instruments. The numbers of expected years with and without activity limitation were estimated by using the Sullivan method. Results: The numbers of expected years of life without activity limitation, at birth, in 1995 and 2004 were 68.5 and 69.7, respectively, in males and 72.1 and 73.0 in females. As a proportion of total life expectancy, at birth, these values represent a decrease from 89.7% to 88.6% in males and from 87.1% to 85.3% in females. The proportion of expected years with a limitation of some activities except activities of daily living (ADL) increased in males and females. The proportion of those with an ADL limitation increased in females, but not in males. Conclusions: The trends in expected years with and without activity limitation suggest that the duration of life with a light or moderate disability increased in Japanese males and females during the period 1995-2004.