Long-term association of economic inequality and mortality in adult Costa Ricans

Abstract

Despite the large number of studies, mostly in developed economies, there is limited consensus on the health effects of inequality. Recently a related literature has examined the relationship between relative deprivation and health as a mechanism to explain the economic inequality and health relationship. This study evaluates the relationship between mortality and economic inequality, as measured by area-level Gini coefficients, as well as the relationship between mortality and relative deprivation, in the context of a middle-income country, Costa Rica. We followed a nationally representative prospective cohort of approximately 16,000 individuals aged 30 and over who were randomly selected from the 1984 census. These individuals were then linked to the Costa Rican National Death Registry until Dec. 31, 2007. Hazard models were used to estimate the relative risk of mortality for all-cause and cardiovascular disease mortality for two indicators: canton-level income inequality and relative deprivation based on asset ownership. Results indicate that there was an unexpectedly negative association between canton income inequality and mortality, but the relationship is not robust to the inclusion of canton fixed-effects. In contrast, we find a positive association between relative deprivation and mortality, which is robust to the inclusion of canton fixed-effects. Taken together, these results suggest that deprivation relative to those higher in a hierarchy is more detrimental to health than the overall dispersion of the hierarchy itself, within the Costa Rican context.