# Closing the Gap

## What is inequality?

Inequality can refer to many concepts. Often, it means the disparity in health between different parts of the population – whether they be segmented by ethnicity, gender, age or wealth.

This product concentrates on explaining the inequality that exists between the most and least deprived parts of our district. It does this by splitting the population into 10 groups (deciles) based on their geographical deprivation scores.

### So what is an ‘Index of Inequality’?

Two measures are then calculated: The Slope Index of Inequality (SII) and the Relative Index of Inequality (RII).

The SII in this product is calculated in a simplified fashion: it is simply the difference between the most and least deprived decile in any given measure. As measures are often different (some are percentages, others are rates per 1000, others rates per 100,000) comparing these differences doesn’t make sense.

As such, we calculated the RII, which divides the SII by the average of the ten deciles, thus creating a fraction that can be compared across measures. We multiply that value by 100 to represent it as a percentage difference from the average.

When you look at an RII score, say of 130, it is telling you that the most deprived areas in the district have a higher rate of that measure by 130% than the average. A negative value suggests that the measure is more common in the least deprived areas in the district.