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National Healthcare Agreement: PI 10-Breast cancer screening rates, 2012 QS

Identifying and definitional attributes

Metadata item type:Help on this termQuality Statement
METeOR identifier:Help on this term500946
Registration status:Help on this termHealth, Retired 14/01/2015

Relational attributes

Indicators linked to this Quality statement:Help on this term

National Healthcare Agreement: PI 10-Breast cancer screening rates, 2012 Health, Retired 25/06/2013

Data quality

Quality statement summary:Help on this term
  • Remoteness and socioeconomic status are based on postcode of residential address at the time of screening, not the location of screening. State/Territory disaggregation by remoteness and socioeconomic status is subject to data quality considerations.
  • Indigenous status data are only available at the national level as numbers are too small to provide meaningful comparison between jurisdictions.
Institutional environment:Help on this term

BreastScreen Australia is a joint program of the Australian Government and State and Territory governments. The target age group is women aged 50–69 years.

BreastScreen Australia program registers in each State and Territory are maintained by jurisdictional Program managers. Data from State and Territory registers are provided to the AIHW annually as unit record data.

BreastScreen Australia is monitored annually. Results are compiled and reported at the national level by the Australian Institute of Health and Welfare (AIHW) in an annual BreastScreen Australia monitoring report.

Timeliness:Help on this term

Data available for the 2012 Council of Australian Governements (COAG) Reform Council report is based on the two-year calendar period 1 January 2009 to 31 December 2010. Data are presented as a rate for the two-year period to reflect the recommended screening interval.

Accessibility:Help on this term

The BreastScreen Australia annual reports are available via the AIHW website where they can be downloaded free of charge.

Interpretability:Help on this term

While numbers of women screened are easy to interpret, calculation of age-standardised rates is more complex and the concept may be confusing to some users. Information on how and why age-standardised rates have been calculated and how to interpret them is available in all AIHW BreastScreen Australia monitoring reports, for example, the BreastScreen Australia monitoring report 2008–2009.

Relevance:Help on this term

BreastScreen Australia registers collect information on all breast cancer screening undertaken as part of BreastScreen Australia. The use of ERP based on Census data for denominators provide the most comprehensive data coverage possible. While BreastScreen data are complete, some breast cancer screening may occur outside the program, and thus this is not a measure of all breast cancer screening in Australia. It is not possible to estimate the number of women screened outside BreastScreen Australia. The BreastScreen Australia data used to calculate this indicator are of high quality.

For participation nationally, the numerator is the number of women aged 50–69 years screened in each State and Territory in 2009 and 2010, extracted from unit record data supplied by each State and Territory. The denominator is the average of the 2009 and 2010 Australian Bureau of Statistics (ABS) estimated resident population (ERP) for women aged 50–69 years.

Caution is required when examining differences across states and territories of Australia due to the substantial differences in population, area, geographic structure, policies and other factors.

For participation by Indigenous status, the numerator for Indigenous is the number of women aged 50–69 years screened in each State and Territory in 2009 and 2010 who self-reported that they were Indigenous at the time of their screen. Non‑Indigenous is the number of women aged 50–69 years screened in each State and Territory in 2009 and 2010 who self‑reported that they were not Indigenous at the time of their screen. Women who choose not to identify as either Indigenous or non‑Indigenous are classified as ‘not stated’ and are not included in either numerator.

Caution is required when examining differences across Indigenous status, as some States and Territories do not allow for the ‘not stated’ category, and some Indigenous women may choose not to identify as such when presenting to a BreastScreen Australia service. Thus, some Indigenous women may be incorrectly assigned non‑Indigenous status in the data presented.

For participation by remoteness and socioeconomic status, the numerator is the number of women screened in 2009 and 2010 aged 50–69 years who reside in each of the remoteness and socioeconomic status categories. A postal area (POA) to remoteness concordance and a POA to socioeconomic status concordance are used to allocate women screened to remoteness and socioeconomic status categories based on their postcode nationally. The denominator is the average of the 2009 and 2010 ABS ERP for women aged 50–69 years in each remoteness and socioeconomic status category, generated by applying a POA to remoteness concordance and a POA to socioeconomic status concordance to POA ERP.

Caution is required when examining differences across remoteness and socioeconomic status categories for several reasons. First, while the postcode of women screened is interpreted as postcode of residence, some women may supply an address other than where they reside, or their postcode may be invalid or missing. Second, because the concordances are based on the 2006 Census, the accuracy of both Australian Standard Geographical Classification (ASGC) and Socio-Economic Indexes for Areas (SEIFA) Index of Relative Socio-economic Disadvantage (IRSD) diminishes due to subsequent changes in demographics within some postcode boundaries, and some boundaries themselves may have changed over time. Third, many valid postcodes are omitted from the socioeconomic status concordance in particular, meaning that many screened women are unable to be allocated to a socioeconomic status category (the remoteness concordance contains a more comprehensive list of postcodes, but some women will still be missed).

Breakdown of remoteness and socioeconomic status categories by State and Territory may introduce an additional source of inaccuracy, since screened women, once allocated a category, also need to be allocated to the State or Territory. Because some postcodes cross State and Territory boundaries, there is the potential for some women to be allocated to a State or Territory different to the one in which they reside.

Accuracy:Help on this term

This indicator is calculated on data that have been supplied to the AIHW by individual State and Territory registers. Prior to publication, the results of analyses are referred back to States and Territories for checking and clearance. Any errors found by states and territories are corrected once confirmed. Thus participation by State and Territory, based on the State or Territory in which the woman was screened, is both robust and readily verified.

However, States and Territories are unable to check or verify participation by State and Territory of residence.

States and Territories are also unable to check or verify participation by Indigenous status, participation by remoteness or participation by socioeconomic status, since their data, once supplied to the AIHW, are nationalised and thereby lose their State or Territory identity. Further, due to the very small numbers involved, disaggregation of participation by Indigenous status by State and Territory is not robust, and leads to issues around confidentiality and comparability.

The number of women who choose not to identify as either Indigenous or non‑Indigenous, and the number of Indigenous women who choose not to identify as Indigenous are sources of inaccuracy in the data. While the latter cannot be quantified, the former can for those States and Territories that use the ‘not stated’ category; in 2009-2010, 8,209 women did not identify as either Indigenous or non‑Indigenous nationally.

The allocation of women screened to a remoteness area and socioeconomic status by their postcode introduces a level of inaccuracy

These concordances are based on 2006 boundaries and classifications, while the current data for this indicator are for 2009-2010. Overall, many new postcodes may not have valid socioeconomic status or remoteness data available, and many may have changed classification group since 2006 and be giving inaccurate information now.

Further, there may not be a postcode for all women screened, or the postcode supplied may not be valid. For those women that do have a valid postcode, many cannot be allocated to a remoteness or socioeconomic category, as their postcode may not be included in the concordances — this is a greater issue for socioeconomic status, since this concordance contains fewer postcodes than does the remoteness concordance. This may affect some remoteness and socioeconomic categories more than others.

The number of women screened in 2009-2010 that are unable to be allocated to a category are as follows (based on State or Territory of postcode):

Remoteness: 456 women excluded (NSW: 392 excluded; Vic:  29 excluded; Qld: 16 excluded; WA: 0 excluded; SA: 0 excluded; Tas: 0 excluded; ACT: 1 excluded; NT: 0 excluded).

Socioeconomic status: 6,515 women excluded (NSW: 1,710 excluded; Vic: 1,253 excluded; Qld: 860 excluded; WA: 1,945 excluded; SA: 327 excluded; Tas: 104 excluded; ACT: 18 excluded; NT: 298 excluded).

No adjustments have been made to account for excluded women in the data.

Women residing in postcodes that cross boundaries are allocated to the state or territory according to ABS classifications (e.g. 0872 includes women who reside in NT, SA and WA, but are allocated to NT).

Women are counted only once in the two-year period 1 January 2009 to 31 December 2010, even if they were screened more than once during this period. All women screened in each State and Territory are included in order to present the most accurate national picture of breast cancer screening.

Cell suppression was required for some data due to denominators less than 1,000.

The Estimated Resident Population data are provided by the ABS.

Coherence:Help on this term

Some of these data are published annually in Program monitoring reports prepared by the AIHW. These reports include participation by State and Territory, participation by Indigenous status, and participation by remoteness and socioeconomic status categories nationally. Data for 2009–2010 will not be published until 2012.

State and Territory participation will differ between these data and those published in BreastScreen Australia monitoring report 2009–2010, because State and Territory participation in BreastScreen Australia monitoring reports is based on State or Territory of screen, rather than State or Territory of residence, since this is more appropriate for program monitoring. However, participation by Indigenous status, remoteness areas and socioeconomic status categories nationally will be the same.

Source and reference attributes

Submitting organisation:Help on this termAustralian Institute of Health and Welfare

Relational attributes

Related metadata references:Help on this term

Supersedes National Healthcare Agreement: PI 10-Breast cancer screening rates, 2011 QS Health, Superseded 04/12/2012

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