Functional transitions and active life expectancy for older Japanese living in a community

We examined functional transitions in both the activities of daily living (ADL), and instrumental activities of daily living (IADL), over a 1-year interval among older Japanese living in a community, then estimated their physically active life expectancy (PALE) and instrumentally active life expectancy (IALE). In 1992, all residents aged 65 or older who lived in Saku City, Nagano, Japan, were followed-up over the 1-year interval. A self-administrated questionnaire, which involved age, sex, five ADL items, and five IADL items, was used for each survey in both 1992 and 1993. Of the baseline cohort (n=10,098), we received 9533 analyzable questionnaires at the follow-up survey in 1993. During the follow-up, 92 and 87% of subjects who were initially independent in ADL and IADL remained independent, respectively. PALE for men and women were estimated to be 16.0 and 18.9 at 65 years of age, respectively. IALE for men and for women were estimated to be 12.8 and 14.6 at the age of 65, respectively. Proportions of the PALE to total life expectancy (TLE) at any age did not greatly differ between men and women; however, men had a slightly larger proportion of IALE to TLE at any given age than women.