IRSAD — Index of Relative Socio-economic Advantage and Disadvantage. Combines indicators of advantage (e.g. high income, skilled occupations) and disadvantage. Higher decile = more advantaged relative to other Australian areas.
IRSD — Index of Relative Socio-economic Disadvantage. Focuses on disadvantage only (e.g. low income, unemployment, limited education). Higher decile = less disadvantage nationally.
A new SEIFA edition typically follows each census; the ABS has not announced a release date beyond 2021.