title: Work-based social networks and health status among Japanese employees.
abstract: BACKGROUND
  Despite the worldwide trend towards more time being spent at work by employed people, few studies have examined the independent influences of work-based versus home-based social networks on employees' health. We examined the association between work-based social networks and health status by controlling for home-based social networks in a cross-sectional study.
  
  
  METHODS
  By employing a two-stage stratified random sampling procedure, 1105 employees were identified from 46 companies in Okayama, Japan, in 2007. Work-based social networks were assessed by asking the number of co-workers whom they consult with ease on personal issues. The outcome was self-rated health; the adjusted OR for poor health compared employees with no network with those who have larger networks.
  
  
  RESULTS
  Although a clear (and inverse) dose-response relationship was found between the size of work-based social networks and poor health (OR 1.53, 95% CI 1.03 to 2.27, comparing those with the lowest versus highest level of social network), the association was attenuated to statistical non-significance after we controlled for the size of home-based social networks. In further analyses stratified on age groups, in older workers (> or =50 years) work-based social networks were apparently associated with better health status, whereas home-based networks were not. The reverse was true among middle-aged workers (30-49 years). No associations were found among younger workers (<30 years).
  
  
  CONCLUSIONS
  The present study suggests a differential association of alternative sources of social support on health according to age groups. We hypothesise that these patterns reflect generational differences in workers' commitment to their workplace.
authors.affiliation: Department of Epidemiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. etsuji-s@cc.okayama-u.ac.jp
authors.forename: E
authors.initials: E
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Takao
authors.forename: S V
authors.initials: SV
authors.lastname: Subramanian
authors.forename: H
authors.initials: H
authors.lastname: Doi
authors.forename: I
authors.initials: I
authors.lastname: Kawachi
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D007398:Interpersonal Relations; D007564:Japan; D007588:Job Satisfaction; D008297:Male; D008875:Middle Aged; D016272:Occupational Health; D012944:Social Support; D011795:Surveys and Questionnaires; D017132:Workplace / Q000523:psychology*; D055815:Young Adult