Local Government Areas
The Local Government Areas (LGAs) presented in the PHIDU Social Health Atlases are based on the Australian Statistical Geography Standard (ASGS): Volume 3 - Non ABS Structures, July 2016.
LGAs are an Australian Bureau of Statistics (ABS) approximation of officially gazetted LGAs as defined by each State and Territory Local Government Department. LGAs cover incorporated areas of Australia. For further information regarding the LGA structure, refer to the ABS information at: Australian Statistical Geography Standard (ASGS): Volume 3 - Non ABS Structures, July 2016.
Caveat on LGA data quality
The data presented by Local Government Area (LGA) have in the majority of cases , been estimated from the postcode or Statistical Areas Level 2 of the address, as the LGA of usual residence was not more accurately geocoded (e.g., from the street address). Estimates produced in this way are of variable quality, as the allocation from a postcode to one or more LGAs is based on the proportion of the total population falling within LGAs covered by the postcode. The proportional allocations are as providedby the Australian Bureau of Statistics (ABS)
This method does not account for variations in the proportion of a postcode varying between different constituent LGAs or parts of LGAs according to different population characteristics such as age groups or Indigenous status, or the location of facilities which can alter the proportion (e.g., a nursing home in part of the postcode will not be recognised by this method).
Cherbourg (S) in Queensland provides an example of the poor quality of outcomes that can result from this process. Under the ABS allocation, Cherbourg (S) is allocated 26.2% of the population of postcode 4605. However, almost three quarters (72.4%) of the Aboriginal and Torres Strait Islander population of postcode 4605 is estimated to live in Cherbourg (S) and not in either of the other two LGAs allocated population from the postcode. As a result of this approach, the Australian Childhood Immunisation Register (ACIR) recorded 14 children at age 1 year in 2017, 12 of whom were immunised. Using data more accurately geocoded by ABS, there were 46 births in Cherbourg (S), indicating a substantial shortfall in the data in the ACIR.
The quality indicators of LGA estimates produced by the ABS include Good (348 LGAs), Acceptable (126 LGAs) or Poor (70 LGAs) as listed here. The definitions for these quality indicators are as follows:
- Good - The ABS expect that the correspondence used has converted data to a high degree of accuracy and users, therefore the converted data will reflect the actual characteristics of the geographic areas involved.
- Acceptable - The ABS expect that the correspondence used has converted data to a reasonable degree of accuracy, though caution needs to be applied as the quality of the converted data will vary and may differ in parts from the actual characteristics of the geographic areas involved.
- Poor - The ABS expect that there is a high likelihood the correspondence used has not converted data accurately, therefore the converted data should be used with caution and may not reflect the actual characteristics of many of the geographic areas involved.
- Not known - Not known.
PHIDU is in contact with data custodians to obtain better quality data for LGAs.
All Population Census data and data for deaths (as presented for premature and avoidable mortality) are geocoded more accurately, as are the data for some records for some states for hospital admissions, perinatal data, cancer incidence and cancer screening. Data for childhood immunisations, HPV vaccinations and income support payments have been produced using ABS correspondence files and are therefore less accurate.