Disability in older adults: evidence regarding significance, etiology, and risk.

OBJECTIVES: This article synthesizes and assesses current evidence about the importance of physical disability to older adults. It then considers the applications of research findings to clinical geriatrics practice.
RESULTS: Physical disability is a major adverse health outcome associated with aging. Certain subgroups of older adults, including individuals with mobility difficulty, with preclinical functional changes, and persons who are hospitalized, are at particularly high risk of becoming disabled or experiencing disability progression. The major underlying causes of physical disability are chronic diseases, including both acute events, such as hip fracture and stroke and slowly progressive diseases such as arthritis and heart disease. These diseases appear to have task-specific effects; understanding this may assist in setting treatment and prevention goals. Comorbidity, particularly certain combinations of chronic diseases, is a strong risk factor for disability in itself. Recent trials indicate that clinical interventions may be able to prevent onset or progression of disability.
CONCLUSIONS: Available evidence now suggests clinical approaches to both treatment and prevention of disability and directions for defining optimal clinical care for the future.