Decreasing income inequality and emergence of the association between income and premature mortality: Spain, 1970-2010

This study evaluates the relationship between income and mortality in Spain over a long period of declining in income inequality. The ratio between income in the richest and poorest provinces was 2.74 in 1970 and 2.10 in 2010. Pearson correlation coefficients for the association between provincial income and the measures of mortality were estimated, as well as absolute and relative differences between the mortality rates of the poorest and richest provinces. The correlation coefficient between income and infant mortality decreased from −0.59 in 1970 to −0.17 in 2010, and lost significance from 1995 onwards. The coefficient for premature all-cause mortality increased from −0.04 in 1970 to −0.40 in 2010, and acquired significance beginning in 2005. The coefficient also increased in mortality from cardiovascular, respiratory and digestive diseases. No association was found between provincial income and cancer mortality or mortality from injuries. The findings on premature mortality do not support the theory that decreasing income inequality will lead to reduced inequalities in mortality.