Measures of functional status in community-dwelling elders

OBJECTIVE: To evaluate two performance-based measures of functional status and assess their correlation with self-report measures. DESIGN: Cross-sectional study. PARTICIPANTS: Of the 363 community-dwelling elders enrolled in a trial of comprehensive geriatric assessment who participated, all had at least one of four target conditions (urinary incontinence, depression, impaired functional status, or history of falling). MEASUREMENTS: Two performance-based measures, National Institute on Aging (NIA) Battery, and Physical Performance Test (PPT), and three self-report functional status measures, basic and intermediate activities of daily living and the Short-Form-36 (SF-36) physical functioning subscale, were used. Measures of restricted activity days, patient satisfaction and perceived efficacy mere also used. MAIN RESULTS: All measures were internally consistent. There was a high correlation between the NIA and PPT (kappa = 0.71), while correlations between the performance-based and self-report measures ranged from 0.37 to 0.50. When patients with values above the median on the two performance-based measures were compared with those below, there were significant differences (P less than or equal to .0001) for age, number of medications, and the physical function, pain, general health, and physical role function SF-36 subscales. CONCLUSIONS: Performance-based measures correlated highly with each other and moderately with questionnaire-based measures. Performance-based measures also had construct validity and did not suffer from floor or ceiling effects.