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Global cognition and 8‐year survival among Japanese community‐dwelling older adults
Author(s) -
Iwasa Hajime,
Kai Ichiro,
Yoshida Yuko,
Suzuki Takao,
Kim Hunkyung,
Yoshida Hideyo
Publication year - 2013
Publication title -
international journal of geriatric psychiatry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 129
eISSN - 1099-1166
pISSN - 0885-6230
DOI - 10.1002/gps.3890
Subject(s) - hazard ratio , confidence interval , proportional hazards model , confounding , demography , medicine , prospective cohort study , cognition , cohort study , longitudinal study , gerontology , cohort , psychiatry , pathology , sociology
Objective We sought to examine the longitudinal relationship between cognitive function and all‐cause mortality among Japanese community‐dwelling older adults, using an 8‐year prospective cohort study design with mortality surveillance. Methods A total of 454 men and 386 women, aged 70 years and older, participated in the study. The Mini Mental State Examination (MMSE) was administered to assess global cognition. The total MMSE score and subscale scores were used as independent variables, and age, gender, education level, chronic disease, sensory deficit, depressive symptoms, and instrumental activities of daily living were used as covariates. Results During the follow‐up period, 191 subjects (139 men and 52 women) died, and 64 subjects (31 men and 33 women) moved to a different region of Japan and were lost to follow‐up. Use of the multivariate Cox proportional hazards model, adjusted for potential confounders, showed that global cognition was significantly and independently associated with mortality (hazard ratio [HR] = 1.59, 95% confidence interval [CI]: 1.14–2.23 and HR = 2.81, 95% CI: 1.77–4.36 for the middle [24–27 points] and lowest [0–23 points] categories, respectively). Among the MMSE subscales, place orientation (HR = 1.57, 95% CI: 1.09–2.25), calculation (HR = 1.67, 95% CI: 1.18–2.35), and delayed recall (HR = 1.42, 95% CI: 1.03–1.96), were also significantly and independently associated with mortality. Conclusions Our study suggests that among older individuals, those with lower levels of cognitive function are more likely to have a shorter lifespan compared with those with higher cognitive functioning. Copyright © 2012 John Wiley & Sons, Ltd.