title: Community social capital and tooth loss in Japanese older people: a longitudinal cohort study.
abstract: OBJECTIVE
  To date, no study has prospectively examined the association between social capital (SC) in the community and oral health. The aim of this longitudinal cohort study was to examine the association between both community-level and individual-level SC and tooth loss in older Japanese people.
  
  
  METHODS
  Prospective cohort study
  
  
  METHODS
  We utilised data from the Japan Gerontological Evaluation Study (JAGES) performed in 2010 and 2013 and conducted in 525 districts.
  
  
  METHODS
  The target population was restricted to non-institutionalised people aged 65 years or older. Participants included 51 280 people who responded to two surveys and who had teeth at baseline.
  
  
  METHODS
  The primary outcome measure was loss of remaining teeth, measured by the downward change of any category of remaining teeth, between baseline and follow-up.
  
  
  RESULTS
  The mean age of the participants was 72.5 years (SD=5.4). During the study period, 8.2% (n=4180) lost one or more of their remaining teeth. Among three community-level SC variables obtained from factor analysis, an indicator of civic participation significantly reduced the risk of tooth loss (OR 0.93; 95% CI 0.88 to 0.99). The individual-level SC variables 'hobby activity participation' and 'sports group participation' were also associated with a reduced risk of tooth loss (OR 0.88; 95% CI 0.81 to 0.95 and OR 0.90; 95% CI 0.82 to 0.99, respectively).
  
  
  CONCLUSIONS
  Living in a community with rich SC and individuals with good SC is associated with lower incidence of tooth loss among older Japanese people.
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Miyagi, Japan.
authors.forename: Shihoko
authors.initials: S
authors.lastname: Koyama
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Miyagi, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Aida
authors.affiliation: Department of Social Welfare, Nihon Fukushi University, Aichi, Japan.
authors.forename: Masashige
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Health Education and Health Sociology, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kondo
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Miyagi, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Miyagi, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Matsuyama
authors.affiliation: Department of Health Education and Health Sociology, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Yukako
authors.initials: Y
authors.lastname: Tani
authors.affiliation: Center for Preventive Medical Sciences, Chiba University, Chiba, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Sasaki
authors.affiliation: Center for Preventive Medical Sciences, Chiba University, Chiba, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Kondo
authors.affiliation: Department of Community Health and Preventive Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ojima
authors.affiliation: Division of Dental Sociology, Department of Oral Science, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka City, Kanagawa, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Miyagi, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Tsuboya
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Miyagi, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Osaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007564:Japan; D008137:Longitudinal Studies; D008297:Male; D009909:Oral Health; D011446:Prospective Studies; D012111:Residence Characteristics; D066270:Social Capital; D058992:Social Participation; D016388:Tooth Loss
keywords: Cohort study; Multilevel analysis; Panel data; Social capital; Tooth loss