Factor analysis of social capital questionnaire used in Urban HEART study in Tehran

Social capital composed of networks, norms and values, which facilitates cooperation within and between groups to achieve mutual benefits and common goals. Social capital increases the benefits of investing in physical and human capital. In a society that favors more social capital, collaboration is easier. This study investigates the validity and reliability of a social capital tool, which had been administered through a large population-based survey using factor analysis.

Data were obtained from Urban Health Equity Assessment and Response Tool (Urban HEART-1) survey in Tehran. Factor analysis is a method of discovering structural position of variables to reduce them into a limited number of components which are more fundamental. The reliability of the questionnaire and main components of the tool were investigated through factor analysis.

According to factor analysis, three main components of social capital including, individual trust, cohesion/ social support and social trust/associative relations, were recognized. These three components explained 66.14% of total variance of the social capital tool. Also, overall Cronbach's alpha coefficient was 0.88 which indicates high reliability of the questionnaire.

Social capital tool, which was administered in Urban HEART project, covers the main components of social capital framework with high reliability and validity, which is suitable to be used in other population-based surveys.