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 c
omprehensive geriatric assessment who participated, all had at least one of
four target conditions (urinary incontinence, depression, impaired functio
nal 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 fu
nctional status measures, basic and intermediate activities of daily living
and the Short-Form-36 (SF-36) physical functioning subscale, were used. Me
asures of restricted activity days, patient satisfaction and perceived effi
cacy mere also used.
MAIN RESULTS: All measures were internally consistent. There was a high cor
relation 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. W
hen patients with values above the median on the two performance-based meas
ures were compared with those below, there were significant differences (P
less than or equal to .0001) for age, number of medications, and the physic
al function, pain, general health, and physical role function SF-36 subscal
es.
CONCLUSIONS: Performance-based measures correlated highly with each other a
nd moderately with questionnaire-based measures. Performance-based measures
also had construct validity and did not suffer from floor or ceiling effec
ts.