[Cognitive function as the factor determining higher-level competence in community-dwelling elderly: comprehensive health examination for the community elderly for the prevention of the geriatric syndrome and a bed-ridden state ("otasha-kenshin")].
OBJECTIVE
This study was conducted to examine age-related differences in cognitive function, and their relation to higher-level competence of elderly living in an urban community.


METHODS
Participants were 438 individuals (males 168, females 270) aged 70 to 84 years living in an urban community in Tokyo. Three cognitive performance tests, the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Digit Symbol, Word Fluency Test, and the WAIS-R Digit Span, were employed for estimating cognitive function, and the TMIG Index of Competence for measuring higher-level competence. In the Index, three constructions: "Instrumental Self-Maintenance", "Intellectual Activity", and "Social Role" were involved.


CONCLUSIONS
Age-related differences in the cognitive tests were analyzed using ANCOVA controlling for educational year. Age-related differences between younger elderly (70-79 years old) and older elderly (80-84 years old) were observed with the WAIS-R Digit Symbol, Word Fluency Test and the WAIS-R Digit Span. The results indicate that information processing speed, executive function and primary memory in community-dwelling elderly continue to decline in old age, and this trend is salient in the old-old. We carried out partial correlation analysis and multiple regression analysis for exploring the relationships between cognitive function and the sub-scales in the TMIG Index of Competence, controlling for age and educational year. Cognitive function was significantly and positively related with the sub-scales in the Index, this being especially robust for "Intellectual Activity". The results suggest that higher-level competence can be modestly determined with reference to cognitive function, and "Intellectual Activity" may have a stronger relation with cognitive function than the other two sub-scales in the Index.
Iwasa
Hajime
H
Japan Foundation for Aging and Health, Department of Epidemiology, Tokyo Metropolitan Institute of Gerontology.
Suzuki
Takao
T
Yoshida
Hideyo
H
Kim
Hunkyung
H
Shimmei
Masaya
M
Yoshida
Yuko
Y
Furuna
Taketo
T
Sugiura
Miho
M
Nishizawa
Satoshi
S
Xiuying
Hu
H
Shinkai
Shoji
S
Kumagai
Shu
S
Fujiwara
Yoshinori
Y
Watanabe
Shuichiro
S
Yukawa
Harumi
H
D000203:Activities of Daily Living; D000368:Aged / Q000523:psychology*; D000369:Aged, 80 and over; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D016743:Mental Competency; D014041:Tokyo