Measuring global health inequity

Abstract

Background: Notions of equity are fundamental to, and drive much of the current thinking about global health. Health inequity, however, is usually measured using health inequality as a proxy - implicitly conflating equity and equality. Unfortunately measures of global health inequality do not take account of the health inequity associated with the additional, and unfair, encumbrances that poor health status confers on economically deprived populations.

Method: Using global health data from the World Health Organization's 14 mortality sub-regions, a measure of global health inequality (based on a decomposition of the Pietra Ratio) is contrasted with a new measure of global health inequity. The inequity measure weights the inequality data by regional economic capacity (GNP per capita).

Results: The least healthy global sub-region is shown to be around four times worse off under a health inequity analysis than would be revealed under a straight health inequality analysis. In contrast the healthiest sub-region is shown to be about four times better off. The inequity of poor health experienced by poorer regions around the world is significantly worse than a simple analysis of health inequality reveals.

Conclusion: By measuring the inequity and not simply the inequality, the magnitude of the disparity can be factored into future economic and health policy decision making.

Figure 1

The Lorenz curve of the global distribution of health (DALYs) by WHO mortality sub-region.

Figure 2

The log ratio of expected to actual per capita health (DALYs) illustrating the inequality of health distribution by WHO mortality sub-region.

Figure 3

The log ratio of expected to actual per capita health (DALYs) weighted by per capita wealth (GNP) illustrating the inequity of health distribution by WHO mortality sub-region.