Abstract
OBJECTIVES: To determine the relative importance of geriatric impairments (in muscle strength, physical capacity, cognition, vision, hearing, and psychological status) and chronic diseases in predicting subsequent functional disability in longitudinal analyses. DESIGN: Longitudinal data from the Cardiovascular Health Study were analyzed. Multivariable Cox hazards regression modeling was used to analyze associations between time-dependent predictors and onset of disability in activities of daily living (ADLs) and mobility. SETTING: Four communities across the United States (Sacramento County, CA; Washington County, MD; Forsyth County, NC; and Allegheny County, PA). PARTICIPANTS: Five thousand eight hundred eighty-eight elderly persons. MEASUREMENTS: Data were collected annually through in-person examinations. RESULTS: ADL disability developed in 15% of participants and mobility disability in 30%. A single multivariable model was developed that included demographics, marital status, body mass index, and number of impairments and diseases. The hazard ratios (HRs) of having one, two, and three or more geriatric impairments (vs none) for the outcome of ADL disability were 2.12 (95% confidence interval (CI)=1.63-2.75), 4.25 (95% CI=3.30-5.48), and 7.87 (95% CI=6.10-10.17), respectively, and for having one, two, and three or more chronic diseases were 1.75 (95% CI=1.41-2.19), 2.45 (95% CI=1.95-3.07), and 3.26 (95% CI=2.53-4.19), respectively. Similarly, the HRs of having one, two, and three or more impairments for the outcome of mobility disability were 1.48 (95% CI=1.27-1.73), 2.08 (95% CI=1.77-2.45), and 3.70 (95% CI=3.09-4.42), respectively, and for having one, two, and three or more diseases were 2.06 (95% CI=1.76-2.40), 2.80 (95% CI=2.36-3.31), and 4.20 (95% CI=3.44-5.14), respectively. CONCLUSION: Number of geriatric impairments was more strongly associated than number of chronic diseases with subsequent ADL disability and nearly as strongly associated with the subsequent mobility disability.