Predictive validity of the classification schema for functional mobility tests in instrumental activities of daily living decline among older adults.
OBJECTIVE
To determine predictive validity for cut points of the Timed Up & Go (TUG) test and life-space assessment (LSA) on decline in instrumental activities of daily living (IADLs) among older adults.


METHODS
Cross-sectional and 1-year follow-up study.


METHODS
Preventive health care services.


METHODS
In a cross-sectional study, 2404 older adults (65-100 y) were recruited to determine cut points for the TUG and LSA for IADLs limitation. For longitudinal analysis, 436 older adults (65-100 y) were followed over 1 year to explore the validity of a classification model using the cut points to predict incident IADLs decline.


METHODS
Not applicable.


METHODS
The TUG, LSA, and Tokyo Metropolitan Institute of Gerontology index of IADLs measurement.


RESULTS
The cut points associated with IADLs limitations for the TUG and LSA were 12 seconds and 56 points, respectively. Participants were classified into fast/high (most able; TUG <12 and LSA >56), fast/low, slow/high, and slow/low (vulnerable; TUG > or =12 and LSA < or =56) groups; there were 813 (34%), 385 (16%), 246 (10%), and 960 (40%) participants in each group, respectively. The proportions of participants with IADLs limitation in the most able, fast/low, slow/high, and vulnerable groups were 19%, 64%, 61%, and 89%, respectively. The vulnerable group included significantly more participants with IADLs limitation than any other group (P<.001). Compared with a most able group, the odds ratios of IADLs decline for the fast/low and vulnerable groups were 2.52 (95% confidence interval 1.15-5.53, P<.05) and 2.87 (95% confidence interval 1.38-5.96, P<.01), respectively.


CONCLUSIONS
The combination of TUG and LSA identifies persons with future IADLs decline and has the potential to be used by community health care services to target individualized interventions.
Research Team for Promoting Independence of the Elderly, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan. shimada@tmig.or.jp
Hiroyuki
H
Shimada
Patricia
P
Sawyer
Kazuhiro
K
Harada
Satomi
S
Kaneya
Kenji
K
Nihei
Yasuyoshi
Y
Asakawa
Chiharu
C
Yoshii
Akiyoshi
A
Hagiwara
Taketo
T
Furuna
Tatsuro
T
Ishizaki
D000203:Activities of Daily Living / Q000145:classification; D000368:Aged; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D007564:Japan; D008297:Male; D051346:Mobility Limitation; D009043:Motor Activity / Q000502:physiology*; D011237:Predictive Value of Tests