title: The Hatoyama Cohort Study: design and profile of participants at baseline.
abstract: BACKGROUND
  Investigation of frailty among elderly adults and development of prevention strategies to address this are critical in delaying progression of functional decline and thus extending healthy life expectancy. However, there has been no Japanese epidemiologic cohort study of frailty. The Hatoyama Cohort Study was launched in 2010 to identify factors that predict functional decline and to establish strategies to prevent frailty among community-dwelling elderly Japanese. This report describes the study design and the profile of the participants at baseline.
  
  
  METHODS
  The Hatoyama Cohort Study is a prospective study of community-dwelling individuals aged 65 years or older living in the town of Hatoyama in Saitama Prefecture, Japan. Comprehensive information, including socioeconomic status, physiological indicators, physical, psychological, and cognitive function, social capital, neighborhood environment, and frailty, was collected in a baseline survey using face-to-face interviews in September 2010. Survival time, long-term care insurance certification, and medical and long-term care costs after the baseline survey will be followed. In addition, a follow-up survey will be conducted in the same manner as the baseline survey every 2 years.
  
  
  RESULTS
  A total of 742 people participated in the baseline survey (mean age: 71.9 ± 5.2 years, men: 57.7%, living alone: 7.7%). Almost all participants were independent in their daily lives, and approximately 10% were categorized as frail on the kaigo-yobo (care prevention) checklist.
  
  
  CONCLUSIONS
  The Hatoyama Cohort Study is expected to contribute to the development of strategies that prevent frailty in later life and extend healthy life expectancy in Japan's rapidly aging society.
authors.affiliation: Research Team for Social Participation and Community Health, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan. murayama@tmig.or.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Murayama
authors.forename: Mariko
authors.initials: M
authors.lastname: Nishi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Mi-Ji
authors.initials: MJ
authors.lastname: Kim
authors.forename: Hiroto
authors.initials: H
authors.lastname: Yoshida
authors.forename: Hidenori
authors.initials: H
authors.lastname: Amano
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Shoji
authors.initials: S
authors.lastname: Shinkai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D016330:Frail Elderly / Q000706:statistics & numerical data*; D006801:Humans; D057187:Independent Living / Q000706:statistics & numerical data*; D007564:Japan; D008297:Male; D011446:Prospective Studies; D012107:Research Design