Income Inequality and Mortality Owing to Breast Cancer: Evidence From Brazil

The relationship between breast cancer and inequality income is unclear. This study analyzed the correlation between income inequality and mortality standardized by age and proportional mortality owing to breast cancer among Brazilian women.

This is an ecological study using data of the federative units and Federal District of Brazil in 2010. The age-standardized mortality owing to breast cancer was estimated using data from the Department of Informatics of Brazil's Unified Health System. Income inequality indicators used included the Gini index, Theil-L index, Palma index, and the ratio of income distribution quintiles obtained from the United Nations Development Program. We used Pearson correlation and linear regression adjusted for income per capita and other variables.

An increase of 0.1 in the Gini index was associated with increases of 9.8 deaths per 100,000 women (95% confidence interval [CI], 1.7-17.9); an increase in the Palma index was associated with increases in mortality of 0.7 deaths per 100,000 women (95% CI, 0.1-1.4), an increase in the Theil-L index was associated with increases in mortality of 4.9 deaths per 100,000 women (95% CI, 1.9-7.9), and of 0.8 (95% CI, 0.2-1.5) in the proportional mortality.

Income inequality, as assessed by the Gini, Palma, and Theil-L indexes, is positively associated with an increase in breast cancer mortality in Brazil.