Functional status and active life expectancy among senior citizens in a small town in Japan

The objectives of this study were to understand transition patterns and mechanisms of functional status, and to estimate active life expectancy (ALE) among senior citizens in a small town in Japan. With data drawn from surveys conducted annually from 1998 to 2002 (n=638 at baseline), prevalence and incidence of functional disability in activities of daily living (ADL) and instrumental activities of daily living (IADL) were described and compared between the sexes. Then relationships between potential predictors and functional decline through a 4-year follow-up were examined using logistic regression. Finally, active and disabled life expectancy was estimated by Katz's method. At baseline, 9 and 12% of subjects were dependent in performing ADL and IADL, respectively. Prevalence and incidence rates increased with age. The risk of mortality increased by 2.2-5.0-fold when the subject was functionally dependent at the previous year. Advanced age, difficulty in walking and poor interest were shown to be significant predictors of loss of independence in ADL. Mean durations with disability in ADL and IADL among women were longer than among men by around 1 year. Population-specific preventive care programs considering physical, cognitive and social aspects are needed not only to maximize ALE but also to improve quality of life during survival period with disability especially in old women.