Measures of functional status in community-dwelling elders

Abstract

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). I n the last 15 years, a tremendous amount of research on quantifying how well individuals function has been reported. 1 Valid, reliable instruments have been developed to measure impairment, screen for early disability, and measure change over time. Assessing function is particularly important in the elderly, as the prevalence of functional disability increases with age. 2 Most instruments have relied either on patient self-report, 3 or on direct observation of the individual performing a variety of tasks (performance-based measures). 4 Although there is widespread agreement that screening for functional status in older persons is important, 5 the preferred method is still uncertain. Moreover, it is unclear whether self-report and performance-based measures can be used interchangeably. Previous studies comparing different measures of functional status assessment have typically found a good but not great correlation. The reason for this less-than-perfect agreement is not clear. Some possibilities are that the scales are measuring different aspects of function, that function is too complex to measure precisely with questionnaires or short performance assessments, or that the method of assessment is responsible for the differences. 6 When considering screening for functional impairment in clinical settings, several questions remain: Which instrument should be used? Is one method (self-report vs performance-based) preferable? Does the method of measurement affect the type of impairment detected? Using data obtained from community-dwelling elders, we addressed three study questions: (1) whether two commonly used performance-based measures, the National Institute on Aging (NIA) Battery of lower extremity function 7 and the Physical Performance Test (PPT), 8 are reliable and valid; (2) how well these two performance-based measures correlate with each other and with self-report measures of function; and (3) whether there are particular areas in which these two types of measures correlate highly. MEASUREMENTS:

Quality of life in older people: A structured review of generic self-assessed health instruments

“…With the exception of the COOP, GQL, IHQL and SQL, all instruments have evidence to support their ability to discriminate between groups defined by a range of socio-demographic, health and health service 0.90 (physical function) [80] 0.79 (social function) [90] 0.82 to 0.94 [91] use variables. This is most extensive for the EQ-5D, HSQ-12, NHP, SF-12, SF-36 and SIP.…”

Virtual Short Physical Performance Battery

“…Typically, the association between performance-based and selfreport assessments of activities is low to moderate (2,4,5,(7)(8)(9)(10). One explanation for this is that the instruments measure different aspects of the same construct, that is, actual versus perceived ability to do a task (8).…”

Batteries assessing health related fitness in the elderly: a brief review

“…Although this battery constitutes in itself an objective way to assess the functional level, it is normally used together with another tests such as the "Tinetti gait score" or the "6-min walking test", with which it is perfectly correlated, obtaining a more complete assessment at the same time [21]. Furthermore, it is not unusual (in studies seeking a more thorough physical and functional assessment) to administer this battery in coordination with the SPPB, since they are also perfectly correlated [43]. The PPT seems to be an appropriate way of assessing those daily life activities involving strength, balance, and flexibility, although it has also been used successfully to evaluate the effects of training programs [20] or the level of autonomy of sick populations [32].…”