Predictors for functional decline among nondisabled older Japanese living in a community during a 3-year follow-up

OBJECTIVES: To examine predictors for functional decline in basic activities of daily living (BADL) as well as predictors for decline in instrumental activities of daily living (IADL) among nondisabled older Japanese people living in a community during a 3-year interval from 1992 to 1995. DESIGN: A prospective cohort study. SETTING: A community-based environment. PARTICIPANTS: A total of 583 men and women aged 65 to 89 at baseline who were independent in both BADL and IADL. MEASUREMENTS: Independent variables regarding various factors potentially associated with functional decline were obtained from an interview survey and medical examinations at baseline. Dependent variables were functional status in BADL and IADL obtained at the time of the 3-year follow-up. RESULTS: During the 3-year follow-up, significant predictors for functional decline in BADL and only IADL decline included (1) age of greater than or equal to 75, (2) less hand-grip strength, and (3) a history of hospitalization during the past I year. In addition, having poor intellectual activities and having poor social roles were identified as significant predictors for functional decline in only IADL during the 3-year follow-up. Furthermore, not having the habit of taking a walk was identified as a significant predictor of functional decline in BADL during the 3-year interval. CONCLUSION: Having a high level hand-grip strength, good intellectual activities, and good social roles are strongly associated with remaining independence in IADL for the nondisabled Japanese persons aged greater than or equal to 65.