Does self-reported function correspond to objective measures of functional impairment?

INTRODUCTION: The relationship between self-reported function and objective measures of physiological function among disabled older women was analyzed to determine the validity of self-reported function, and to identify the hierarchy of self-reported task difficulty most associated with loss of independence as a basis to inform treatment progress goals.
METHODS: A randomly selected population of older women with moderate to high disability was selected from community-dwelling women 65 to 101 years old from the Women's Health and Aging Study I baseline evaluation (n = 987). Cross-sectional analyses evaluated the association of self-reported function with objective physiological impairment measures.
RESULTS: The results indicated that (1) disabled older women self-reported a broad range of physical function levels; (2) self-reported function correlated closely with objective measures of physiological impairments; (3) "preclinical disability," as measured by self-reported modification of task performance in the absence of perceived difficulty, has validity even in a disabled population, and identifies a group intermediate between those who are high functioning in a task and those with difficulty; and (4) there is an apparent gradation in physiological impairment measures with reported loss of functional independence.
CONCLUSION: These findings suggest the validity of self-report functional disability measures and the potential to use these measures to identify already-disabled older adults at risk for further functional degradation and potential targets for intervention.