Low linking social capital as a predictor of coronary heart disease in Sweden: a cohort study of 2.8 million people.

This study investigated the association between the recently minted concept of linking social capital and incidence of coronary heart disease (CHD). A follow-up study of 1,358,932 men and 1,446,747 women in Sweden aged 45-74 years was conducted between 1 January 1998 and 31 December 1999. Neighbourhood linking social capital was conceptualised as proportions of individuals voting in local government elections at neighbourhood level. The neighbourhood- and individual-level factors were analysed within a multilevel framework. Linking social capital was associated with CHD in both men and women beyond individual-level factors: in neighbourhoods with low linking social capital the odds ratios were 1.19 (CI = 1.14-1.24) and 1.29 (CI = 1.21-1.38) for men and women, respectively, after adjustment for age, country of birth, education, marital status, and housing tenure. The significant between-neighbourhood variance (i.e. the random intercept) showed significant differences in CHD incidence between neighbourhoods. Even in a relatively egalitarian society, as exemplified by the Swedish Welfare State, individual health is affected by differences between neighbourhoods in linking social capital. The use of linking social capital represents a novel conceptual advance in research on the association between CHD, one of the major causes of death in Western countries, and the multidimensional aspects of social capital.