Combined prevalence of frailty and mild cognitive impairment in a population of elderly Japanese people

Abstract

Objective: Preventive strategies for frailty and mild cognitive impairment (MCI) are important for avoiding future functional decline and dementia in older adults. The purpose of this study was to use a population-based survey to ascertain the single and combined prevalence of frailty and MCI and to identify the relationships between frailty and MCI in older Japanese adults.

Design: Cross-sectional study.

Setting: General community.

Participants: A total of 5104 older adults (aged 65 years or older, mean age 71 years) who were enrolled in the Obu Study of Health Promotion for the Elderly (OSHPE).

Measurements: Each participant underwent detailed physical and cognitive testing to assess frailty and MCI. We considered the frailty phenotype to be characterized by limitations in 3 or more of the following 5 domains: mobility, strength, endurance, physical activity, and nutrition. Screening for MCI included a standardized personal interview, the Mini-Mental State Examination, and the National Center for Geriatrics and Gerontology-Functional Assessment Tool (NCGG-FAT), which included 8 tasks used to assess logical memory (immediate and delayed recognition), word list memory (immediate and delayed recall), attention and executive function (tablet version of Trail Making Test-part A and B), processing speed (tablet version of digit symbol substitution test), and visuospatial skill (figure selection).

Results: The overall prevalence of frailty, MCI, and frailty and MCI combined was 11.3%, 18.8%, and 2.7%, respectively. We found significant relationships between frailty and MCI (the odds ratio adjusted for age, sex, and education was 2.0 (95% confidence interval 1.5-2.5).

Conclusions: Using the OSHPE criteria, we found more participants with MCI than with frailty. The prevalence of frailty and MCI combined was 2.7% in our population. Future investigation is necessary to determine whether this population is at increased risk for disability or mortality.