title: Prevalence of frailty in Japan: A systematic review and meta-analysis.
abstract: Japan's population is aging more rapidly than that of any other country. Frailty has recently been recognized as an important priority. Understanding the basic epidemiology of frailty in Japan, which is an example of a rapidly aging society, will be beneficial for Japan as well as other countries expecting an aging population. A systematic literature search of 11 electronic databases was conducted in March 2016 using a comprehensive set of Medical Subject Heading and text terms for any studies published in 2000 or later that report the prevalence of frailty among Japanese community-dwelling older people aged 65 years or older. A total of 1529 studies were identified in the systematic search, of which five studies were included in this review. The pooled prevalence of frailty, prefrailty, and robustness was 7.4% (95% confidence interval [CI], 6.1%-9.0%), 48.1% (95% CI, 41.6%-54.8%), and 44.4% (95% CI, 37.2%-51.7%), respectively. A significant degree of heterogeneity was observed. There was no evidence of publication bias. Age-stratified meta-analyses of four studies showed the pooled prevalence of frailty was 1.9%, 3.8%, 10.0%, 20.4%, and 35.1% for those aged 65-69, 70-74, 75-79, 80-84, and ≥85 years, respectively. Pooled prevalence of frailty was 8.1% for women and 7.6% for men. This review showed an overall pooled prevalence of frailty among Japanese community-dwelling older people of 7.4%. The age-stratified analysis suggested that Japanese older people are less frail before their late 70's but frailer in later life than older people in other countries. These findings provide important basic information for all parties involved in Japanese frailty research.
authors.affiliation: Department of Primary Care and Population Health, University College London, London, United Kingdom. Electronic address: gotarokojima@yahoo.co.jp.
authors.forename: Gotaro
authors.initials: G
authors.lastname: Kojima
authors.affiliation: Department of Primary Care and Population Health, University College London, London, United Kingdom.
authors.forename: Steve
authors.initials: S
authors.lastname: Iliffe
authors.affiliation: Research Team for Social Participation and Community Health, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Taniguchi
authors.affiliation: Section for Health Promotion, Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology, Aichi, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimada
authors.affiliation: Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Rakugi
authors.affiliation: Department of Primary Care and Population Health, University College London, London, United Kingdom.
authors.forename: Kate
authors.initials: K
authors.lastname: Walters
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016330:Frail Elderly / Q000706:statistics & numerical data*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D015995:Prevalence
keywords: Community-dwelling older people; Frailty; Japan; Prevalence