title: Testing the association between social capital and health over time: a family-based design.
abstract: BACKGROUND
  The past decade has seen a vast increase in empirical research investigating associations between social capital and health outcomes. Literature reviews reveal 'generalized trust' and 'social participation' to be the most robust of the commonly used social capital proxies, both showing positive association with health outcomes. However, this association could be confounded by unmeasured factors, such as the shared environment. Currently, there is a distinct lack of social capital research that takes into account such residual confounding.
  
  
  METHODS
  Using data from the United Kingdom's British Household Panel Survey (BHPS) (waves thirteen to eighteen, N = 6982), this longitudinal, multilevel study investigates the validity of the association between trust, social participation and self-rated health using a family-based design. As the BHPS samples on entire households, we employed 'mean' and 'difference from the mean' aggregate measures of social capital, the latter of which is considered a social capital measurement that is not biased by the shared environment of the household. We employed Generalized Estimating Equations for all analyses, our two-level model controlling for correlation at the household level.
  
  
  RESULTS
  Results show that after adjusting for the shared environment of the household over a six year period, the association between social participation and self-rated health was fully attenuated (OR = 0.97 (95% confidence interval 0.89-1.06)), while the association with trust remained significant (OR = 1.11 (1.02-1.20)). Other health determinants, such as being a smoker, having no formal qualifications and being unemployed maintain their associations with poor self-rated health.
  
  
  CONCLUSIONS
  The association between social capital (specifically trust and social participation) and self-rated health appear to be confounded by shared environmental factors not previously considered by researchers. However, the association with trust remains, adding to existing empirical evidence that generalized trust may be an independent predictor of health.
authors.affiliation: Center for Primary Health Care Research, Lund University/Region Skåne, Malmö, Sweden. Giuseppe_nicola.giordano@med.lu.se
authors.forename: Giuseppe N
authors.initials: GN
authors.lastname: Giordano
authors.forename: Juan
authors.initials: J
authors.lastname: Merlo
authors.forename: Henrik
authors.initials: H
authors.lastname: Ohlsson
authors.forename: Maria
authors.initials: M
authors.lastname: Rosvall
authors.forename: Martin
authors.initials: M
authors.lastname: Lindström
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005190:Family; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D055361:Multilevel Analysis; D015203:Reproducibility of Results; D012107:Research Design; D058992:Social Participation; D035502:Trust; D006113:United Kingdom; D055815:Young Adult