Cancer screening programs: quarterly data

Activity data

Invitations issued are a count of all screening invitations issued within the relevant period for those within the target age group. Two-yearly screening was only fully rolled out from 2020, and prior to that, specific ages invited within the 50–74 were invited to screen each year. This phasing in of age groups is also reflected in quarterly activity counts. The age groups invited for the periods covered in this report are shown in the section NBCSP age groups invited by year.

Total kits returned are a count of all kits returned during the relevant period. This can include kits issued in a previous period and returned at a later date. It can also include multiple kits per person (invitee) due to expired, spoiled, damaged or incorrectly completed kits.

The number of invites sent and kits returned are presented by state/territory, age group and quarterly and monthly between 2014 and 2023.

Although terminology is similar, activity counts of invites issued or screening kits returned should not be directly compared with the formal NBCSP participation indicator. Activity counts are a count of events, not people.

Participation data

Participation rates represent the percentage of people invited to screen through the NBCSP during the relevant 2-year period who returned a completed screening test within that period or by 30 June of the following year. The number of individuals invited to screen excludes those who deferred or opted out without completing their screening test. As 2-yearly screening was only fully rolled out from 2020, the specific ages invited within the 50–74 age group for the periods covered in this report are shown in the section ‘National Bowel Cancer Screening Program age groups invited by year’ section below.

National Bowel Cancer Screening Program ages invited by year

Two-yearly screening was only fully rolled out from 2020. The specific ages invited within the 50–74 age for the periods covered in this report are shown in the following table:

Table 1: National Bowel Cancer Screening Program ages invited by year

Phase	Start date	End date	Ages invited
1	7 August 2006	30 June 2008	55 and 65
2	1 July 2008	30 June 2011(a)	50, 55 and 65
2(b)	1 July 2011	30 June 2013	50, 55 and 65
3	1 July 2013	31 December 2014	50, 55, 60 and 65
4	1 January 2015	31 December 2015	50, 55, 60, 65, 70 and 74
4	1 January 2016	31 December 2016	50, 55, 60, 64, 65, 70, 72 and 74
4	1 January 2017	31 December 2017	50, 54, 55, 58, 60, 64, 68, 70, 72 and 74
4	1 January 2018	31 December 2018	50, 54, 58, 60, 62, 64, 66, 68, 70, 72 and 74
4	1 January 2019	ongoing	50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72 and 74

Notes

The eligible population for all Phase 2 and 3 start dates incorporate all those turning the target ages from 1 January of that year onwards.

(a) Eligible birth dates, and thus invitations, ended on 31 December 2010.

(b) Ongoing NBCSP funding commenced.

Activity data

Activity data were supplied by BreastScreen Australia state and territory programs. The number of screening mammograms performed are presented by state/territory, age group and quarterly and monthly between 2014 and 2023.

Although terminology is similar, activity counts of screening tests should not be directly compared with the formal BreastScreen Australia participation indicator. Activity counts are a count of events, not people.

Participation data

Participation rates represent the percentage of women in the population aged 50–74 screened by BreastScreen Australia over 2 calendar years. The population denominator was the average of ABS Estimated Resident Population (ERP) (ABS unpublished, 2022) for females aged 50–74 in 2021 and 2022.

BreastScreen Australia changed its target age group from 50–69 years to 50–74 years from July 2013; participation is reported for both the previous and current target age groups to allow comparison of trends with previously reported data.

Activity data

Screening tests are a count of all primary screening HPV tests performed within the relevant period for those within the target age group. Follow-up tests for people who had a positive screening test, or treatment for HPV infection, are not included. Transition from the previous 2-yearly screening program to the renewed 5-yearly screening program occurred from 1 December 2017. Quarterly activity counts are only shown for the renewed NCSP from 2018 onwards as program data for previous years are not comparable.

Although terminology is similar, activity counts of screening tests should not be directly compared with the formal NCSP participation indicator. Activity counts are a count of events, not people.

Participation data

Participation in the NCSP is estimated until 5 years of data are available to calculate 5-year participation. This is defined as the percentage of females in the population aged 25–74 who had at least one cervical screening test (primary screening or 12-month repeat HPV test) in 2018 to 2022. Participation rates were calculated using the ABS Estimated Resident Population (ERP) (ABS unpublished, 2022) for people aged 25–74 in 2018, 2019, 2020, 2021 and 2022, adjusted to exclude the estimated proportion of women who have had a hysterectomy.

In this report the term ‘people’ is used to describe participants in the NCSP. In this context the term ‘people’ is defined as any person with a cervix – this may include women, transgender men, intersex people and non-binary people.

Data in this report are sourced from live databases which are updated over time, with later data supply likely to have a greater level of completeness. Data in this report may differ from other AIHW cancer screening reports, which are sourced at a different time.

Activity data for all screening programs are updated each quarter.

Participation data are updated biannually, first as preliminary participation data pertaining to state and territory, and then as updated final data which also includes Primary Health Network areas and other small geographies. Note that unlike BreastScreen Australia and the NCSP, the NBCSP publishes geography data with both preliminary and final data.

Preliminary participation data for all screening programs are published ahead of their respective AIHW annual monitoring report which might result in minor differences from data published in this web report. In contrast, final participation data published in this web report aligns with the data presented in each program’s annual monitoring reports.

Rounding

Some numbers may be presented rounded to the nearest whole number for percentages, or to the nearest 100 or 1,000 in text. The exact figures are available in the Excel data tables, csv data files and Tableau visualisations.

State or territory

For data on the NBCSP and the NCSP (from 2018 onwards), state or territory refers to the state or territory of residence.

For data on BreastScreen Australia and the NCSP (prior to 2018), state or territory refers to the state or territory in which screening occurred, not the state or territory of residence.

Rates

Rates are calculated from one number (numerator) divided by another number (denominator). The numerator is commonly the number of events in a specified time. The denominator is the population ‘at risk’ of the event. In this report, participation rates (crude, age-specific and age-standardised) are multiplied by 100 and expressed as percentages.

In this report, all rates reported (including national rates reported for a single reporting period) are crude or age-specific rates, unless otherwise stated. Age-standardised rates relate to the target age groups for each respective program. For more information specific to each screening program see ‘Age-standardised rates’ below.

Crude rates

A rate derived from the number of events recorded in a population during a specified time-period without adjustments for other factors such as age. Crude rates are calculated by taking the number of cases occurring in a population with selected characterisics such as sex, eligible age range or living in a same area (numerator) and dividing this number by the corresponding total population with the same characteristics in in the same reference period (denominator). For example, in this report crude participation rates would include the number of eligible people participating in a screening program in a certain state or territory, divided by the total number of people eligible to participate in the same state or territory and within the same reference period. Crude participation rates in this report, are expressed as percentages.

Age-specific rates

A specific type of crude rate derived from the number of cases occurring in each specified age group (numerator) divided by the corresponding population in the same age group (denominator). For example, in this report age-specific participation rates would include the number of people of a certain age participating in a screening program, divided by the number of people eligible to participate (or the number of people in the population of that age). Age-specific participation rates in this report, are expressed as a percentages.

Age-standardised rates

Age-standardisation is a way to remove the influence of age when comparing rates between populations with different age structures. This is usually necessary because the rates of many diseases vary strongly (usually increasing) with age. Screening behaviours also vary with age. To adjust the participation rates, actual age-specific participation rates for each population of interest are applied to one standard population. Adjusted participation rates can then be directly across populations with different age structures. Note that the age-standardised rates are not "real" and should not be reported alone. They are used only for comparative purpose.  

Age-standardised participation rates for the target age group for BreastScreen Australia (50–69 and 50–74) and the NCSP (20–69 prior to 2018 and 25–74 from 2018) are available in the accompanying data tables to allow comparisons to be made over time and across population groups.

Age-standardised participation rates are not available for the NBCSP, since only specific age groups were invited until the program was fully rolled out in 2020. For more information about the age groups invited in different years, see the relevant section in the ‘National Bowel Cancer Screening Program’ section above.

Percentage difference

Percentage difference is a way of expressing the difference between counts or rates, usually over a designated time period.

In this report, we calculate percentage differences in:

• counts of participants over time,
• participation rate over time and
• participation rate between different geographies (states and territories) compared to a reference (Australian average) within the same time period.

Percentage differences are calculated similar to crude rates above, where the count or rate (numerator) is divided by the corresponding reference count or rate (denominator), expressed as a percentage.

Unlike crude rates, percentage differences represent the proportional difference compared to the reference. This is useful to illustrate the overall percentage change in counts or participation rates over time or the magnitude of difference between two participation rates.

Geography

Participation rates in the NBCSP, BreastScreen Australia and the NCSP are presented for the following geographies:

• Primary Health Network (PHN) areas: 31 areas covering Australia, defined by the Department of Health and Aged Care (DHAC 2022)
• Statistical Areas Level 3 (SA3s): 333 areas covering Australia (ABS 2021a)

Participation rates in the NBCSP are also presented for Statistical Areas Level 2 (SA2s): 2,196 areas covering Australia (ABS 2021b) for periods up to 2017–2018, 2019–2020 and 2020–2021. SA2 data for the NBCSP were not available for 2018–2019 due to data quality issues.

Note that SA2s are not available as visualisations, with SA2 data currently only available for download as part of the ‘CSV file: National Cancer Screening programs participation’ zip file located on the Data page

Both SA3s and SA2 are defined by the ABS within the Australian Statistical Geography Standard (ASGS) (ABS 2022):

• The 2011 ASGS (ABS 2010) was used for the 2014–2015 to 2017–2018 NBCSP data, and 2014–2015 and 2015–2016 BreastScreen Australia data in this report.
• The 2016 ASGS (ABS 2016) was used for the 2018–2019 and later NBCSP data, 2016–2017 and later BreastScreen Australia data and NCSP data in this report.

For BreastScreen Australia and the NCSP, population denominators for the PHN geographical areas were derived using ABS Estimated Resident Population (ERP) data by postal areas (ABS unpublished, 2022) and the PHN correspondence file (DHAC 2019). These data were classified according to the PHN 2017 structure (DHAC 2022).

Participation data for some SA3s across the three screening programs were not published due to reliability concerns arising from low numbers in these regions and/or due to poor correspondence (as determined by the Australian Bureau of Statistics).

Assigning geography

For NBCSP invitees prior to the 2019–2020 period, geographic areas (PHNs, SA3s and SA2s) were assigned using Statistical Areas Level 1 (SA1s) of usual residence. For invitees without reliable SA1 details geographic areas were assigned using postcode of usual residence. For the 2018–2019 participation by PHN and SA3 geographical areas were reported and assigned using postcode of usual residence. From the 2019–2020 period onward, SA2 geographic area data were directly assigned based on longitude and latitude information of the program invites. SA2 information was then used to assign the PHNs and SA3s. For invitees without reliable address of residence, the postcodes of usual residence were used and assigned to an SA2.

Note that when used to assign geographic areas, some postcodes cross the boundaries of PHNs, SA3s or SA2s with the use of postcode correspondences potentially leading to some minor inaccuracies in results. Where SA1 codes, SA2 codes or postcodes could not be attributed to a PHN, SA3 or SA2, these invitees were included in an 'Unknown' group in the data tables and are excluded from data visualisations.

For BreastScreen Australia, PHNs and SA3s were assigned using postcode of usual residence. Where postcodes could not be attributed to a PHN or SA3, these women were included in an 'Unknown' group where possible in the data tables and were excluded from data visualisations. For Queensland, the 17 SA3s that had poor concordance with postcode, had their participation data derived from SA2 geocoded information available for women residing in Queensland and screening in Queensland only.

For the NCSP, from the January 2023 release, SA2 geographic area data was directly assigned based on longitude and latitude information and was used to assign PHN areas and SA3s. For invitees without reliable SA2 details, PHN areas and SA3s were assigned using postcode of usual residence. Where SA2s and postcodes could not be attributed to a PHN for Tas, ACT or NT, state information was used to allocated women to the single PHN corresponding to these states. Where PHNs remained unallocated or postcodes could not be attributed to an SA3, these women were included in an 'Unknown' group, where possible in the data tables, and were excluded from data visualisations. For analyses where a postcode overlapped PHN areas or SA3 boundaries, the relevant records were attributed based on the percentage of the population within that postcode that fell within the PHN area or SA3.

Participation by geographic areas represents the geographic data available within the relevant data source at the time of first publication and are not retrospectively updated. This is particularly of relevance to NCSR data for the NBCSP, which updates geography data biannually, as some improvements to geographical information may be made over time.

Correspondences

Correspondence files for PHN were sourced from the Department of Health and Aged Care website for all 3 screening programs and were classified according to the PHN concordance available at the time of analysis (DHAC 2019). PHNs were established in June 2015, and some of the geographic information presented includes data before that date. For further details on PHNs see the Department of Health and Aged Care’s website (2022). 

Correspondence files for SA3s and SA2s for NBCSP data (from the 2014–2015 to the 2017–2018 period) and BreastScreen Australia data (from the 2014–2015 to 2015–2016 period) were initially sourced from the 2011 ASGS (ABS 2010). For NBCSP data (from the 2018-2019 period onwards), BreastScreen Australia data (from the 2016–2017 period onwards) and the NCSP, correspondence files for SA3s were initially sourced from the 2016 ASGS (ABS 2016).

The correspondences produced by the ABS can now be found on data.gov.au by searching for: ‘ASGS’, the 'year', and ‘correspondences’ (ABS 2018a, 2018b).

The number of people in different geographic areas (PHNs, SA3s or SA2s) may not sum the to 'Australia' total due to rounding. The Australia total also includes some records that could not be attributed to a geographic area.

SA3s and SA2s with a numerator less than 20, a denominator less than 100, or those with poor SA2, SA3 or postcode correspondences (as determined by the Australian Bureau of Statistics) were suppressed.

For a full list of AIHW products that include data and results by small areas (for example, by PHNs) see AIHW data by geography.

Symbols used in this report

Symbol	Description
n.a.	not available, not applicable
n.p.	not published because of small numbers, confidentiality and/or other concerns about the quality of the data)
. .	no data/insufficient data

Abbreviations used in this report

Abbreviation	Description
ABS	Australian Bureau of Statistics
AIHW	Australian Institute of Health and Welfare
ASGS	Australian Statistical Geography Standard
DHAC	Australian Government Department of Health and Aged Care
ERP	Estimated Resident Population
iFOBT	Immunochemical faecal occult blood test
HPV	human papilloma virus
NBCSP	National Bowel Cancer Screening Program
NCSP	National Cervical Screening Program
NCSR	National Cancer Screening Register
PHN	Primary Health Network
SA1	Statistical Areas Level 1
SA2	Statistical Areas Level 2
SA3	Statistical Areas Level 3

ABS (Australian Bureau of Statistics) (n.d.), Australian Statistical Geography Standard (ASGS), ABS website, accessed 6 December 2022.

ABS (Australian Bureau of Statistics) (unpublished), Estimated Resident Population by 2017 Primary Health Network boundaries by single year of age and sex as of June 2021 [data set], ABS, Canberra.

ABS (Australian Bureau of Statistics) (2010), Australian Statistical Geography Standard (ASGS): Volume 1 — Main Structure and Greater Capital City Statistical Areas, July 2011, catalogue number 1270.0.55.001, ABS, Australian Government, accessed 6 December 2022.

ABS (Australian Bureau of Statistics) (2016), Australian Statistical Geography Standard (ASGS): Volume 1 — Main Structure and Greater Capital City Statistical Areas, July 2016, catalogue number 1270.0.55.001, ABS, Australian Government, accessed 6 December 2022.

ABS (Australian Bureau of Statistics) (2018a). ASGS Geographic Correspondences (2011) [data set], data.gov.au, accessed 6 December 2022.

ABS (Australian Bureau of Statistics) (2018b). ASGS Geographic Correspondences (2016) [data set], data.gov.au, accessed 6 December 2022.

ABS (Australian Bureau of Statistics) (2021a) Australian Statistical Geography Standard (ASGS): Volume 3 — Main Structure and Greater Capital City Statistical Areas – Statistical Area Level 3, July 2021, catalogue number 1270.0.55.003, ABS, Australian Government, accessed 6 December 2022.

ABS (Australian Bureau of Statistics) (2021b) Australian Statistical Geography Standard (ASGS): Volume 3 — Main Structure and Greater Capital City Statistical Areas – Statistical Area Level 2, July 2021, catalogue number 1270.0.55.003, ABS, Australian Government, accessed 6 December 2022.

ABS (Australian Bureau of Statistics) (2022), Regional population, ABS Website, accessed 6 December 2022.

AIHW (Australian Institute of Health and Welfare) (n.d.) AIHW Data by Geography, AIHW website, accessed 6 December 2022.

DHAC (Department of Health and Aged Care) (2019) Primary Health Networks (PHN) – concordance files – Postal Areas – 2017 [data set], Health website, accessed 6 December 2022.

DHAC (Department of Health and Aged Care) (2022) Primary Health Networks (PHNs), Health website, accessed 6 December 2022.