Work-based social networks and health status among Japanese employees.
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.
Suzuki
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E
Department of Epidemiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. etsuji-s@cc.okayama-u.ac.jp
Takao
S
S
Subramanian
S V
SV
Doi
H
H
Kawachi
I
I
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