Social capital and health: implications for public health and epidemiology.

Public health and its "basic science", epidemiology, have become colonised by the individualistic ethic of medicine and economics. Despite a history in public health dating back to John Snow that underlined the importance of social systems for health, an imbalance has developed in the attention given to generating "social capital" compared to such things as modification of individual's risk factors. In an illustrative analysis comparing the potential of six progressively less individualised and more community-focused interventions to prevent deaths from heart disease, social support and measures to increase social cohesion faired well against more individual medical care approaches. In the face of such evidence public health professionals and epidemiologists have an ethical and strategic decision concerning the relative effort they give to increasing social cohesion in communities vs expanding access for individuals to traditional public health programs. Practitioners' relative efforts will be influenced by the kind of research that is being produced by epidemiologists and by the political climate of acceptability for voluntary individual "treatment" approaches vs universal policies to build "social capital". For epidemiologists to further our emerging understanding of the link between social capital and health they must confront issues in measurement, study design and analysis. For public health advocates to sensitise the political environment to the potential dividend from building social capital, they must confront the values that focus on individual-level causal models rather than models of social structure (dis)integration. The evolution of explanations for inequalities in health is used to illustrate the nature of the change in values.