The impact of changes in different aspects of social capital and material conditions on self-rated health over time: a longitudinal cohort study.

Individual aspects of social capital have been shown to have significant associations with health outcomes. However, research has seldom tested different elements of social capital simultaneously, whilst also adjusting for other well-known health determinants over time. This longitudinal individual-level study investigates how temporal changes in social capital, together with changes in material conditions and other health determinants affect associations with self-rated health over a six year period. We use data from the British Household Panel Survey, a randomly selected cohort which is considered representative of the United Kingdom's population, with the same individuals (N=9303) providing responses to identical questions in 1999 and 2005. Four measures of social capital were used: interpersonal trust, social participation, civic participation and informal social networks. Material conditions were measured by total income (both individual and weighted household income), net of taxation. Other health determinants included age, gender, smoking, marital status and social class. After the baseline sample was stratified by health status, associations were examined between changes in health status and changes in all other considered variables. Simultaneous adjustment revealed that inability to trust demonstrated a significant association with deteriorating self-rated health, whereas increased levels of social participation were significantly associated with improved health status over time. Low levels of household and individual income also demonstrated significant associations with deteriorating self-rated health. In conclusion, it seems that interpersonal trust and social participation, considered valid indicators of social capital, appear to be independent predictors of self-rated health, even after adjusting for other well-known health determinants. Understandably, how trust and social participation influence health outcomes may help resolve the debate surrounding the role of social capital within the field of public health. 2009. Published by Elsevier Ltd.