RELATIONSHIP BETWEEN PHYSICAL PERFORMANCE AND SELF-PERCEIVED PHYSICALFUNCTION

OBJECTIVE: The objective of this study was to compare two methods of m easuring physical function in subjects with a broad range of abilities and to evaluate the effects of cognitive, social, educational, and ag e factors on the relationship between the two methods. DESIGN: Multipl e regression analysis was used to compare self-perceived (dependent va riables) with performance measures (independent variables). Covariates included age, gender, Mini-Mental State Exam score, education, living status, and depression score. SETTING: Five community-dwelling and tw o nursing home sites. PARTICIPANTS: 417 community-dwelling subjects an d 200 nursing home residents aged 62-98 years. MEASUREMENTS: Self-perc eived physical function was assessed with the physical dimension summa ry score of the Sickness Impact Profile, which comprises three subscal es: ambulation, mobility, and body care and movement. Physical perform ance was evaluated by self-selected gait speed, chair-stand time, maxi mal grip strength, and a balance score. RESULTS: Nursing home resident s and community-dwellers were significantly different (P < .0001) in a ll variables except age and gender. Self-perceived and performance-bas ed measures were moderately correlated, with a range from r = -.194 to r = -.625 (P < .05). Gait speed was the strongest independent predict or of self-perceived physical function in both groups. Symptoms of dep ression were also an independent predictor of self-perceived function in nursing home residents; subjects who had such symptoms report more self-perceived dysfunction than would be predicted based on performanc e tests. CONCLUSIONS: Self-selected gait speed is a global indicator o f self-perceived physical function over a broad range of abilities. Ex ternal determinants (depressive symptoms, cognitive function, marital status, etc.) affect self-perceived function in both groups, but gait speed is the greatest single predictor of self-perceived function. In nursing home residents depressive symptomatology is related to self-pe rceived