Objectives: To estimate the incidence of chronic activities of daily living (ADL) disability and to analyze the sociodemographic, health status, adverse lifestyle, and leisure-time physical activity predictors for chronic ADL disability.
Design: We recruited a cohort of community-dwelling older people in Taipei, Taiwan, who were not ADL disabled in August 1993, and we followed them until August 1996.
Settings and participants: The study subjects were 1321 community-dwelling people aged 65 years or older who were ADL intact at the initial interview in August 1993. The study sample was a subset of a probability sample (n = 1583) randomly selected from household registrations in the four districts of the Taipei metropolitan area.
Measurements: Baseline information regarding various factors potentially associated with the development of chronic ADL disability was assessed and collected at the beginning of the study. Study participants were assessed annually for ADL function by a structured home interview using a six-item scale. Participants who were unable to perform independently at least one of the six items--eating, bathing, dressing, toileting, transfers, and walking inside the house--for more than 3 months were considered chronically ADL disabled. Cox proportional hazard regression models were utilized to examine the independent effect of the potential predictors on risk of chronic ADL disability.
Results: During the 3-year study period, 145 (11.0%) participants developed chronic ADL disability, 58 (4.4%) participants were lost to follow-up, and 83 (6.3%) participants died. Multiple hazard regression analysis showed that individuals aged 70 to 79 years or older than age 80 had increased risk of ADL disability (relative risk: 2.05 (95% confidence interval (CI), 1.35-3.11) and 3.89 (95%CI, 2.33-6.50), respectively) compared with those participants younger than age 70. Risk of chronic ADL disability was inversely associated with routine exercise (RR = 0.52; 95% CI, 0.39-0.68).
Conclusions: Age is the most significant predictor of chronic ADL disability. Lack of routine exercise is also a significant predictor of ADL disability in older adults.