Abstract
BackgroundCognitive function is an important contributor to health among elderly adults. One reliable measure of cognitive functioning is information processing speed, which can predict incident dementia and is longitudinally related to the incidence of functional dependence. Few studies have examined the association between information processing speed and mortality. This 8-year prospective cohort study design with mortality surveillance examined the longitudinal relationship between information processing speed and all-cause mortality among community-dwelling elderly Japanese.MethodsA total of 440 men and 371 women aged 70 years or older participated in this study. The Digit Symbol Substitution Test (DSST) was used to assess information processing speed. DSST score was used as an independent variable, and age, sex, education level, depressive symptoms, chronic disease, sensory deficit, instrumental activities of daily living, walking speed, and cognitive impairment were used as covariates.ResultsDuring the follow-up period, 182 participants (133 men and 49 women) died. A multivariate Cox proportional hazards model showed that lower DSST score was associated with increased risk of mortality (hazard ratio [HR] = 1.62, 95% CI = 0.97–2.72; HR = 1.73, 95% CI = 1.05–2.87; and HR = 2.55, 95% CI = 1.51–4.29, for the third, second, and first quartiles of DSST score, respectively).ConclusionsSlower information processing speed was associated with shorter survival among elderly Japanese.
Highlights
Cognitive function is an important contributor to health among elderly adults
We examined the relationship between information processing speed and all-cause mortality among community-dwelling elderly Japanese during an 8-year follow-up period
As in previous reports,[2,11,12] our findings suggest that slow information processing speed is a reliable predictor of mortality among community-dwelling older adults
Summary
Recent studies have identified a longitudinal association between cognitive function and mortality among older adults.[1,2] One reliable measure of cognitive functioning is information processing speed, which refers to how quickly an individual can accurately process new input from the environment and retrieve stored information from memory.[3] It can be assessed objectively by measuring reaction time[4] or by using tests such as the Digit Symbol Substitution Test (DSST).[5] Information processing speed is closely correlated with chronologic age.[6] Slow processing speed predicts incident dementia[7] and is longitudinally related to the incidence of functional dependence in activities of daily living (ADL) and instrumental ADL (IADL).[8] In addition, recent studies reported that information processing speed among elderly adults can be increased by interventions that improve cognitive functioning.[9,10] because information processing speed has a central role in cognitive aging, is closely associated with incidence of functional dependence, and is responsive to intervention strategies, further study of its relationship to mortality could aid development of longevitypromoting strategies. Methods: A total of 440 men and 371 women aged 70 years or older participated in this study. Conclusions: Slower information processing speed was associated with shorter survival among elderly Japanese
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
