Population Health Areas: Overview


On 1 July 2011, the Australian Bureau of Statistics introduced a new geographical structure, the Australian Statistical Geography Standard (ASGS). The equivalent area level in the new structure to the Statistical Local Area (SLA) is the Statistical Areas Level 2 (SA2); this is now the area to which the majority of data is coded by government agencies in the States, Territories, and at the national level. However, the implementation of this new geography introduced a problem for presenting small area health data, as there were approximately 2,200 SA2s, compared to around 1,400 SLAs, which PHIDU published as 1,100 SLA groups. This means that the new (SA2) areas have, on average, about half the population of the old (SLA) areas, resulting in a far greater potential for data not to be available from data custodians, because of their need to maintain confidentiality of the data.

To address this issue, PHIDU constructed a set of areas that maintained much of the value of the SA2 geography, while ensuring that relatively few areas need to have data suppressed. These Population Health Areas (PHA) are comprised of a combination of whole SA2s and multiple (aggregates of) SA2s. Unlike the SLA groups, which were only produced for the few parts of Australia, the SA2 groups have been constructed for the whole of Australia. The use of the next biggest area in the new ABS geography, the SA3, was examined, but with only 338 SA3s, this area level was not going to be effective in showing the extent of variation that exists between areas.

In developing these areas, PHIDU consulted with State and Territory health agencies and incorporated their advice. PHAs based on the 2011 Australian Statistical Geography Standard (ASGS) were first released in the December 2016 release.

PHIDU subsequently updated the PHAs to reflect changes in SA2 boundaries between 2011 and 2016. These changes led to the formation of two new PHAs in the Australian Capital Territory.

There were minimal changes between the 2016 and 2021 PHAs.

The table below summarises the number of SA2s comprised within the PHAs based on 2021 boundaries, and shows that 35.1% of the PHAs comprise one SA2, and another 36.9% of the PHAs comprise two SA2s.

Number of SA2s in PHAs
No. of PHAs % of PHAs SA2s per PHA
409 35.1 1
430 36.9 2
221 19.0 3
58 5.0 4
22 1.9 5
12 1.0 6
5 0.4 7
3 0.3 8
5 0.4 9
1,165 100.0 ..


Population Health Area Correspondences

To find the code and/or name of a PHA, refer to the full list of Population Health Areas 2021 (including Statistical Areas Level 2 (SA2)). In addition, to search for a suburb and determine which PHAs this suburb falls into and what percentage of the suburb's population is in a PHA, refer to the suburb to PHA correspondence for 2021, 2016 and 2011 (xls).