Social capital, health, and health disparities

Purpose: To synthesize the empirical evidence that links social capital to population health with the aim of identifying implications for health disparities research. Methods: A literature search of PubMed and CINAHL databases from January 1990 to June 2002 was done using the search term "social capital." In addition, tables of contents of applicable journals from January 1997 to June 2002 were searched. Reference lists were examined for additional empirical and theoretical articles related to social capital and health. Eighty-four articles were retrieved for review and 19 articles met inclusion criteria. Findings: Although most researchers concluded that their findings supported an association between social capital and health, all research was descriptive, without conceptual development. This gap resulted in (a) lack of distinction of the concept as an attribute of a geographic space or as an individual attribute, (b) problematic use of operational variables, and (c) limited theoretical exploration of causal linkage. These deficits limit the usefulness of the concept for health disparities research. Conclusions: The lack of conceptual development diminishes the usefulness of social capital as a variable for public health research. However, the empirical evidence is sufficient to warrant further work to advance the concept in relation to population health and health disparities.