Outcomes

PI 9 – Adverse events – hospital admission

PI 9 definition

The rate at which people who had a diagnostic assessment between 1 January 2024 and 31 December 2024 were admitted to hospital within 30 days of their assessment.

Rationale: As with any invasive procedure, there is the risk of an adverse event occurring with a colonoscopy. ‘Maximising benefit and minimising harm’ is an important tenet of population screening. Accordingly, it is important to report known harms from screening when monitoring the program’s performance.

Data quality: Complete data for this indicator requires linkage with hospital data, which is being investigated, but is not currently performed. The NCSR should receive information on adverse events for participants who had an assessment (ACSQHC 2020), but provision of these data is not mandated by the NBCSP. However, these data will be used until a more complete data source becomes available. Therefore, there is currently an unknown level of under-reporting for this indicator.

In this report, colonoscopy form and MBS claim data have been supplemented with Participant follow-up function (PFUF) data for those who had a positive screening test, increasing the number of known colonoscopies. See Improvements to the known colonoscopy count in Appendix A for further details.

Guide to interpretation: This indicator includes all people who underwent a diagnostic assessment in the defined period, not all those invited in the defined period. Therefore, assessment counts here may differ to other indicators. As per the adverse event form, unplanned hospital admissions after a colonoscopy are recorded only if they occurred within 30 days of the procedure. 

Those aged 45–49 can now request a screening kit; however, this age group is not reported in this performance indicator.

National hospital admission rate, 2024: 0.5 per 10,000 assessments.

The following apply to the 62,981 people who had a diagnostic assessment in 2024:

Australia-wide: Three people were admitted to hospital within 30 days of assessment, giving an overall Australia-wide hospital admission rate after assessment of 0.5 per 10,000 assessments (Table A3.37). Reporting of adverse events after an NBCSP colonoscopy is required (ACSQHC 2020) but not mandated by the NBCSP - this rate may be underestimated.

Due to concerns about the level of data completeness, no other disaggregations are presented for this indicator.

PI 10 – Incidence of bowel cancer

PI 10 definition

The (estimated) incidence rate for bowel cancer per 100,000 estimated resident population aged 50–74 between 1 January 2025 and 31 December 2025.

Rationale: Incidence data provide contextual information about the number of new cases of bowel cancer in the population, which can inform NBCSP planning.

Data quality: Each Australian state and territory has legislation requiring mandatory reporting of cancer (excluding basal cell and squamous cell carcinomas of the skin). 

The 2021 Australian Cancer Database used in this report contains data on cancers diagnosed up to and including the year 2021.

Guide to interpretation: The latest estimated incidence results (for 2025) are given where possible. However, estimated 2025 incidence numbers are not available for analysis by state or territory, by remoteness and socioeconomic areas, or by Indigenous status. Hence, for these stratifications, the latest actual data to 2021 (the latest year of complete data for all states and territories) are used. 

Those aged 45–49 can now request a screening kit; however, this age group is not reported in this performance indicator (except in appendix table A3.38).

National bowel cancer incidence rate, 2025: 91 new cases per 100,000 people aged 50–74.


The following estimates were calculated for 2025:

Australia-wide: A total of 6,941 people aged 50–74 were diagnosed with bowel cancer, giving an age-standardised rate of 91 new cases per 100,000 people (Table A3.38).

Sex: Of people aged 50–74, men were more likely to be diagnosed with bowel cancer than women (113 new cases per 100,000 males compared with 77 new cases per 100,000 females). When age standardised, rates for males and females were 109 and 74 new cases, respectively, per 100,000 (Table A3.38).

Age: Bowel cancer incidence rates were higher for older age groups. For people in the target age group, the bowel cancer incidence rate increased with increasing age, from 68 new cases per 100,000 people aged 50–54 to 152 new cases per 100,000 people aged 70–74 (Figure 3.27). In comparison, for those aged 45–49, the bowel cancer incidence rate was 39 new cases per 100,000 people.

Figure 3.27: Incidence rate of bowel cancer for people aged 50-74, by sex and age group, Australia, 2025

This vertical bar chart depicts the age-specific incidence rate for males and females aged 50–­74. It shows that males will be more likely to be diagnosed with bowel cancer than females. It also shows that the estimated bowel cancer incidence rate will increase with increasing age.

Source: Table A3.38.

Trend: Among people aged 50–74, the number of new bowel cancer cases per year rose from 4,386 in 1982 to a peak of 8,217 in 2010. The number of new cases per year has declined since then to an estimated 6,941 in 2025. The age-standardised rate for new cases (per 100,000 people aged 50–74) rose from 138 in 1982 to a peak of 164 in 1996 (Figure 3.28). Since then, the rate has fallen, and the ASR is estimated as 91 new cases per 100,000 in 2025. The ASRs for bowel cancer are expected to continue to decline.

Note that bowel cancers diagnosed after a positive NBCSP screen are shown separately in Figure 3.28 (only for the years 2006–2020) and have increased from 2006 as the rollout of the eligible NBCSP target ages were added (completed in 2020).

Figure 3.28: Trend in new cases of bowel cancer, people aged 50–74, Australia, 1982–2025

This combined vertical bar chart/line chart depicts the number of new cases of bowel cancer (bars) and the age-standardised incidence rate (line) for the period 1982–2025 for people aged 50–74. It shows that the number of people diagnosed with bowel cancer slowly increased between 1982 and 2010 (from 4,386 to a peak of 8,217 cases). Since 2010, the number of cases diagnosed has been gradually declining, to an estimated 6,941 in 2025. Meanwhile, the age-standardised incidence rate increased slowly between 1982 and 1996 (from 138 to 164 new diagnoses, respectively, per 100,000 people). It then remained steady until 2007 before gradually declining. The age-standardised incidence rate is estimated to decrease to 91 new diagnoses per 100,000 in 2025.

This combined vertical bar chart/line chart depicts the number of new cases of bowel cancer (bars) and the age-standardised incidence rate (line) for the period 1982–2025 for people aged 50–74. It shows that the number of people diagnosed with bowel cancer slowly increased between 1982 and 2010 (from 4,386 to a peak of 8,217 cases). Since 2010, the number of cases diagnosed has been gradually declining, to an estimated 6,941 in 2025. Meanwhile, the age-standardised incidence rate increased slowly between 1982 and 1996 (from 138 to 164 new diagnoses, respectively, per 100,000 people). It then remained steady until 2007 before gradually declining. The age-standardised incidence rate is estimated to decrease to 91 new diagnoses per 100,000 in 2025.

Notes:

1. Estimated incidence data for 2022–2025 are based on 2012–2021 incidence data and may differ to actual incidence data due to current and ongoing program or practice changes, or COVID-19 pandemic effects. 

2. The ACD currently contains data on all cases of cancer diagnosed from 1982 to 2021 for all states and territories. 

3. Rates were age standardised to the Australian population as at 30 June 2001 and expressed per 100,000 people. 

4. Bowel cancer is defined by ICD-10 codes C18–C20 (including C18.1 – Appendix).

State or territory: In the period 2017–2021, the rate of new cases of bowel cancer per 100,000 people aged 50–74 was highest in Queensland (120 new cases of bowel cancer per 100,000 people) and lowest in Western Australia (98 new cases per 100,000 people) (Table A3.39). The age-standardised rates by state or territory followed a similar pattern to the crude rates, though the Northern Territory had the highest age-standardised rate (116 new cases of bowel cancer per 100,000 people) (Figure 3.29).

Figure 3.29: Incidence rate of bowel cancer for people aged 50-74, by state or territory, Australia, 2017-2021

This vertical bar chart depicts the age-standardised incidence rate by state or territory. It shows that the age-standardised incidence rate was highest for people living in the Northern Territory (116 cases per 100,000 people) and lowest for people living in Western Australia (94.5 per 100,000).

Source: Table A3.39.

Remoteness area: In the period 2017–2021, incidence of bowel cancer per 100,000 people aged 50–74 differed by remoteness area. Age-standardised rates (ASR) are shown in Figure 3.30a and below.

The ASR for new cases of bowel cancer per 100,000 people aged 50–74 was highest for those living in Outer regional areas (121 new cases of bowel cancer per 100,000 people) and lowest for people living in Very remote areas (101 new cases per 100,000 people) (Figure 3.30a).

Socioeconomic area: In the period 2017–2021, incidence of bowel cancer per 100,000 people aged 50–74 differed by socioeconomic area. Age-standardised rates are shown in Figure 3.30b and below.

The ASR for new cases of bowel cancer per 100,000 people aged 50–74 was highest for those living in the lowest (most disadvantaged) socioeconomic areas (122 new cases of bowel cancer per 100,000 people) and lowest for people living in the highest socioeconomic areas (93 new cases per 100,000 people) (Figure 3.30b).

Figure 3.30a: Incidence rate of bowel cancer for people aged 50-74, by remoteness area, Australia, 2017-2021

The figure shows that the age-standardised incidence rate was highest for people living in Outer regional areas with 121 cases per 100,000 people and lowest for people living in Very remote areas with 101 cases per 100,000 people.

Source: Table A3.39.

Figure 3.30b: Incidence rate of bowel cancer for people aged 50-74, by socioeconomic area, Australia, 2017-2021

The figure shows that the age-standardised incidence rate was highest for people living in the lowest socioeconomic areas with 122 cases per 100,000 and lowest for people living in the highest socioeconomic areas with 93 cases per 100,000.

Source: Table A3.39.

Aboriginal and/or Torres Strait Islander people: Reliable national data on the diagnosis of cancer for Indigenous Australians are not available. All state and territory cancer registries collect information on Indigenous status; however, in some jurisdictions, the quality of the data is insufficient for analysis. Information in the Australian Cancer Database (ACD) on Indigenous status is considered to be of sufficient completeness for reporting for New South Wales, Victoria, Queensland, Western Australia, the Australian Capital Territory, and the Northern Territory.

While the majority (91%) of Indigenous Australians live in these 6 jurisdictions, the degree to which data for these jurisdictions are representative of data for all Indigenous Australians is unknown (ABS 2021). For the 6 jurisdictions analysed, 3.6% (1,258 records) of the relevant ACD records had unknown Indigenous status for bowel cancer diagnoses for people aged 50–74 in 2016–2020 (Table A3.40).

The incidence counts and rates for Indigenous and non-Indigenous Australians presented are under-estimated due to the relatively large proportion of people whose Indigenous status is not stated, or not available. Also, it is likely that some Indigenous Australians are misclassified as non-Indigenous Australians. Therefore, the estimates presented in this report should be interpreted with caution. In addition, age-standardised incidence rates should be used to compare the incidence of bowel cancer for Indigenous and non-Indigenous Australians to account for the different age structures of Indigenous and non-Indigenous populations. See Box 3.1 for information on Indigenous rates calculated using Indigenous population estimates from the 2021 Census.

Box 3.1: Indigenous Australians – incidence and mortality: populations and rates

To derive bowel cancer incidence and mortality rates for Indigenous Australians, this report used Indigenous population estimates and projections based on the 2021 Census. Previous monitoring reports used those based on the 2016 Census or earlier. 

Due to a large non-demographic increase in Census counts of Aboriginal and Torres Strait Islander people between 2016 and 2021, the rates for Aboriginal and Torres Strait Islander people in this report are generally lower than, and are not comparable to, those in previous reports.

For further information, see Understanding change in counts of Aboriginal and Torres Strait Islander people and Guide to using historical estimates for comparative analysis and reporting

Based on the data from the 6 jurisdictions analysed, Indigenous Australians aged 50–74 had a crude incidence rate of bowel cancer of 107 per 100,000. Following adjustment for differences in the age structure between the two population groups, Indigenous Australians had a higher incidence rate than non-Indigenous Australians in 2017–2021 (115 and 105 cases, respectively, per 100,000 people) (Figure 3.31).

Figure 3.31: Incidence rate of bowel cancer, by Indigenous status, 50-74, NSW, Vic, Qld, WA, ACT, and NT, 2017-2021

This vertical bar chart depicts the age-standardised incidence rate by Indigenous status. It shows that Indigenous Australians had a slightly higher age-standardised incidence rate than non- Indigenous Australians (115 compared with 105 cases, respectively, per 100,000 people).

Source: Table A3.40

PI 11 – Mortality from bowel cancer

PI 11 definition

The (estimated) mortality rate for bowel cancer per 100,000 estimated resident population aged 50–74 between 1 January 2025 and 31 December 2025. 

Rationale: Mortality data provide contextual information about trends in the level of bowel cancer mortality in the population, which can inform NBCSP planning. 

Data quality: Cause of Death Unit Record File data are provided to the AIHW by the jurisdictional registrars of Births, Deaths and Marriages and the National Coronial Information System (managed by the Victorian Department of Justice) and include causes of death coded by the ABS. It is suspected that bowel cancer deaths are under reported due to issues with death certificate coding (see Appendix A).

Monitoring reports for the NBCSP from 2019 onwards use ICD-10 codes C18–C20, and C26.0 when reporting deaths from bowel cancer using the NMD. This differs from the approach used for versions of the report before 2019 and will result in a greater number of deaths being attributed to bowel cancer (see Box 2.1).

Guide to interpretation: The latest estimated mortality results (for 2025) are given where possible. However, analysis by state or territory, by remoteness and socioeconomic areas, and Indigenous status use the latest actual mortality data (which were to 2023 at the time this report was prepared). 

Those aged 45–49 can now request a screening kit; however, this age group is not reported in this performance indicator (except in appendix table A3.42).

National bowel cancer mortality rate, 2025: 23 deaths per 100,000 people aged 50–74.


The following estimates were calculated for 2025:

Australia-wide: A total of 1,779 people aged 50–74 died from bowel cancer, giving an age-standardised rate of 23 deaths per 100,000 people (Table A3.42).

Sex: Males aged 50–74 were more likely to die from bowel cancer than females (30 deaths per 100,000 males compared with 19 deaths per 100,000 females) (Figure 3.32). When age standardised, rates for males and females were 28 and 18 deaths, respectively, per 100,000 (Table A3.42).

Age: The bowel cancer mortality rate was higher for older age groups (Table A3.42). For people in the target age range, the estimated bowel cancer mortality rate per 100,000 people rose from 12 deaths for those aged 50–54 to 46 deaths for those aged 70–74 (Figure 3.32). In comparison, for those aged 45–49, the estimated bowel cancer mortality rate was 8 deaths per 100,000 people.

Figure 3.32: Mortality rate from bowel cancer for people aged 50-74, by sex and age, Australia 2025

This vertical bar chart shows that the age-specific mortality rate will be higher for males than females in all age groups and increases with advancing age. The mortality rate ranges from 9 (females aged 50–54) to 56 (males aged 70–74).

Source: Table A3.42.

Trend: Since 1985, the age-standardised mortality rate from bowel cancer per 100,000 people aged 50–74 has fallen from 70 to an estimated 23 deaths per 100,000 in 2025 (Figure 3.33). The number of deaths from bowel cancer peaked at 2,635 cases in 1994 and decreased to an estimated 1,779 in 2025. The overall effect of the increasing and ageing Australian population is that, while the age-standardised mortality rate has steadily fallen over time, the actual number of deaths has remained stable or slowly declined.

Figure 3.33: Trend in deaths from bowel cancer, people aged 50–74, Australia, 1982–2025

This combined vertical bar chart/line chart depicts the number of deaths from bowel cancer (bars) and the age-standardised mortality rate (line) for the period 1982–2025 for people aged 50–74. It shows that the number of people who die from bowel cancer has remained relatively steady over this period (despite the increasing and ageing Australian population). After a peak in 1987 of 69 deaths per 100,000 the mortality rate has steadily decreased. It is estimated to decrease to 23 deaths per 100,000 in 2025.

This combined vertical bar chart/line chart depicts the number of deaths from bowel cancer (bars) and the age-standardised mortality rate (line) for the period 1982–2025 for people aged 50–74. It shows that the number of people who die from bowel cancer has remained relatively steady over this period (despite the increasing and ageing Australian population). After a peak in 1987 of 69 deaths per 100,000 the mortality rate has steadily decreased. It is estimated to decrease to 23 deaths per 100,000 in 2025.

Notes:

1. Estimated mortality data for 2024–2025 are based on 2014–2023 mortality data and may differ to actual mortality data due to current and ongoing program or practice changes, or COVID-19 pandemic effects. See Appendix A for further information. 

2. Deaths registered in 2021 and earlier are based on the final version of cause of death data; deaths registered in 2022 are based on the revised version; and deaths registered in 2023 are based on preliminary versions. Revised and preliminary versions are subject to further revision by the ABS. 

3. Rates were age standardised to the Australian population as at 30 June 2001 and expressed per 100,000 people. 

The NBCSP started in 2006 and, from 2020, rollout of biennial screening for all eligible Australians in the current target age group (50–74) was in effect. Once biennial invitations have been in place for a number of years, and actual mortality data are available for 2024 onwards, it will be easier to quantify the program’s impact on bowel cancer mortality. However, studies conducted by the AIHW of people diagnosed with bowel cancer in 2006–2008 showed that NBCSP invitees (particularly those who participated) diagnosed with bowel cancer had less risk of dying from the disease and were more likely to have less advanced cancers when diagnosed than non‑invitees. These findings provide evidence that the NBCSP is contributing to reducing morbidity and mortality from bowel cancer in Australia (AIHW 2014, 2018a, 2018b).

State or territory: In 2019–2023, the mortality rate per 100,000 people aged 50–74 was highest in Tasmania (33 deaths from bowel cancer) and lowest in the Australian Capital Territory (21 deaths) (Table A3.43). The age-standardised rates by state or territory followed a generally similar pattern to the crude rates (Figure 3.34).

Figure 3.34: Mortality rate from bowel cancer for people aged 50-74, by state or territory, Australia, 2019-2023

This vertical bar chart shows that the age-standardised mortality rate was highest for people living in Tasmania (30 deaths per 100,000 people) and lowest for people living in the Australian Capital Territory (20 deaths per 100,000).

Source: Table A3.43.

Remoteness area: In the period 2019–2023, mortality from bowel cancer per 100,000 people aged 50–74 differed by remoteness area. Age-standardised rates are shown in Figure 3.35a and below.

The ASR per 100,000 people aged 50–74 was highest for those living in Outer regional areas (31 deaths from bowel cancer) and lowest for those living in Very remote areas (19 deaths) (Figure 3.35a).

Socioeconomic area: In the period 2019–2023, mortality from bowel cancer per 100,000 people aged 50–74 differed by socioeconomic area. Age-standardised rates are shown in Figure 3.35b and below.

The ASR per 100,000 people aged 50–74 was highest for those living in the lowest socioeconomic areas (32 deaths from bowel cancer) and lowest for those living in the highest socioeconomic areas (20 deaths) (Figure 3.35b).

Figure 3.35a: Mortality rate from bowel cancer for people aged 50–74, by remoteness area, Australia, 2019–2023

The figure shows that the age-standardised mortality rate was highest for people living in Outer regional areas with 31 deaths per 100,000 people and lowest for people living in Very remote areas with 19 deaths per 100,000 people.

Source: Table 3.43.

Figure 3.35b: Mortality rate from bowel cancer for people aged 50–74, by socioeconomic area, Australia, 2019–2023

The figure shows that the age-standardised mortality rate was highest for people living in the lowest socioeconomic areas with 32 deaths per 100,000 and lowest for people living in the highest socioeconomic areas with 20 deaths per 100,000.

Source: Table A3.43.

Aboriginal and/or Torres Strait Islander people: Age-standardised mortality rates should be used to compare the mortality rate from bowel cancer between Indigenous and non-Indigenous Australians to account for the different age structures between the 2 populations. Only mortality data from New South Wales, Queensland, Western Australia, South Australia, and the Northern Territory are considered adequate for reporting by Indigenous status for the period of analyses. Other jurisdictions have a small number of Indigenous deaths, and identification of these in their death registration systems is relatively poor, making the data less reliable. Note that these jurisdictions differ from those used to calculate incidence for Indigenous and non-Indigenous Australians (see Box 3.1).

For the period 2019–2023, 242 Indigenous Australians aged 50–74 died from bowel cancer in Australia, with 212 of these deaths registered in New South Wales, Queensland, Western Australia, South Australia, and the Northern Territory.

In these jurisdictions for the period 2019–2023, Indigenous Australians aged 50–74 had a crude mortality rate of 31 deaths per 100,000. Following adjustment for differences in age structure between the two population groups, mortality from bowel cancer was higher for Indigenous Australians compared with non‑Indigenous Australians (ASRs per 100,000 people of 34 and 26 deaths, respectively, from bowel cancer) (Figure 3.36).

Figure 3.36: Mortality rate from bowel cancer, 50-74 years, by Indigenous status, NSW, Qld, WA, SA, and NT, 2019–2023

This vertical bar chart depicts the age-standardised mortality rate by Indigenous status. It shows that Indigenous Australians had a higher age‑standardised bowel cancer mortality rate than non-Indigenous Australians (34 compared with 26 deaths, respectively, per 100,000 people).

Source: Table A3.44.