A6a Interval cancers
Box A6: Confidence intervals
Confidence intervals (CIs) are presented in this report only for interval cancer rates. This is because it is deemed important to show the degree of error due to rare events in small populations to avoid potential misinterpretation of data and/or to present data consistently with data in other publications.
Where shown, 95% CIs can be used to determine if a statistically significant difference exists between compared values: where the CIs do not overlap, the difference between rates is greater than that which could be explained by chance and is therefore regarded as statistically significant. Because overlapping CIs do not imply that the difference between two rates is definitely due to chance, it can only be stated that no statistically significant differences were found—and not that no differences exist.
Judgment should be exercised in deciding whether any differences shown are of clinical significance.
State and territory | Crude rate | AS rate | 95% CI |
|---|---|---|---|
NSW | 7.0 | 6.4 | 4.5–8.7 |
Vic | 7.9 | 9.6 | 6.2–13.9 |
Qld | 6.1 | 7.3 | 4.4–11.1 |
WA | 12.7 | 9.8 | 5.9–14.8 |
SA | 4.0 | 2.5 | 1.0–5.2 |
Tas | 3.8 | 4.2 | 0.4–15.6 |
ACT | 6.9 | 8.6 | 0.3–28.7 |
NT | 3.7 | 7.9 | 0.2–44.2 |
Australia | 7.3 | 7.5 | 6.1–8.9 |
Note: Age‑standardised (AS) rate is the number of interval cancers detected per 10,000 person-years, age-standardised to the population of participants attending a BreastScreen Australia service in 2008; ‘95% CI’ are 95% confidence intervals.
Source: AIHW analysis of BreastScreen Australia data.
State and territory | Crude rate | AS rate | 95% CI |
|---|---|---|---|
NSW | 6.0 | 6.0 | 5.4–6.6 |
Vic | 6.2 | 6.1 | 5.5–6.8 |
Qld | 6.0 | 5.9 | 5.2–6.6 |
WA | 8.7 | 8.4 | 7.3–9.6 |
SA | 5.8 | 5.9 | 4.8–7.2 |
Tas | 6.9 | 6.9 | 5.1–9.3 |
ACT | 5.6 | 5.1 | 3.1–7.8 |
NT | 5.1 | 5.4 | 2.0–11.9 |
Australia | 6.3 | 6.3 | 5.9–6.6 |
Note: Age‑standardised (AS) rate is the number of interval cancers detected per 10,000 person-years, age-standardised to the population of participants attending a BreastScreen Australia service in 2008; ‘95% CI’ are 95% confidence intervals.
Source: AIHW analysis of BreastScreen Australia data.
State and territory | Crude rate | AS rate | 95% CI |
|---|---|---|---|
NSW | 10.1 | 11.2 | 8.3–14.6 |
Vic | 11.5 | 12.2 | 8.5–16.7 |
Qld | 11.3 | 11.5 | 8.1–15.9 |
WA | 12.8 | 10.8 | 5.5–18.0 |
SA | 12.1 | 10.1 | 5.2–16.9 |
Tas | 13.7 | 13.3 | 5.0–27.9 |
ACT | 7.2 | 4.6 | 1.0–13.6 |
NT | 11.8 | 7.7 | 1.6–22.6 |
Australia | 11.1 | 11.3 | 9.6–13.1 |
Note: Age‑standardised (AS) rate is the number of interval cancers detected per 10,000 person-years, age-standardised to the population of participants attending a BreastScreen Australia service in 2008; ‘95% CI’ are 95% confidence intervals.
Source: AIHW analysis of BreastScreen Australia data.
State and territory | Crude rate | AS rate | 95% CI |
|---|---|---|---|
NSW | 10.3 | 10.3 | 9.6–11.2 |
Vic | 12.5 | 11.9 | 10.9–12.8 |
Qld | 12.5 | 12.4 | 11.3–13.4 |
WA | 10.9 | 10.4 | 9.0–11.8 |
SA | 12.3 | 12.5 | 10.8–14.4 |
Tas | 10.9 | 10.6 | 8.1–13.5 |
ACT | 10.6 | 9.5 | 6.6–13.1 |
NT | 7.9 | 7.1 | 3.0–14.3 |
Australia | 11.5 | 11.3 | 10.8–11.8 |
Note: Age‑standardised (AS) rate is the number of interval cancers detected per 10,000 person-years, age-standardised to the population of participants attending a BreastScreen Australia service in 2008; ‘95% CI’ are 95% confidence intervals.
Source: AIHW analysis of BreastScreen Australia data.
Age group (years) | Number (0–12 months) | Crude rate (0–12 months) | Number (13–24 months) | Crude rate (13–24 months) |
|---|---|---|---|---|
40–49 | 279 | 8.5 | 327 | 11.7 |
50–59 | 740 | 6.4 | 1,121 | 10.7 |
60–69 | 701 | 6.3 | 1,254 | 12.0 |
70–74 | 292 | 6.8 | 502 | 12.5 |
75+ | 96 | 10.0 | 141 | 15.8 |
Note: Crude rate is the number of interval cancers detected per 10,000 person-years.
Source: AIHW analysis of BreastScreen Australia data.
State and territory | Crude rate | AS rate | 95% CI |
|---|---|---|---|
NSW | 8.5 | 8.7 | 7.0–10.7 |
Vic | 9.7 | 10.9 | 8.3–13.9 |
Qld | 8.6 | 9.4 | 7.1–12.1 |
WA | 12.7 | 10.2 | 6.9–14.1 |
SA | 8.1 | 6.3 | 3.7–9.8 |
Tas | 8.6 | 8.6 | 3.8–16.7 |
ACT | 7.0 | 6.6 | 1.5–16.1 |
NT | 7.7 | 7.9 | 1.1–22.4 |
Australia | 9.1 | 9.3 | 8.2–10.5 |
Note: Age‑standardised (AS) rate is the number of interval cancers detected per 10,000 person-years, age‑standardised to the population of participants attending a BreastScreen Australia service in 2008; ‘95% CI’ are 95% confidence intervals.
Source: AIHW analysis of BreastScreen Australia data.
State and territory | Crude rate | AS rate | 95% CI |
|---|---|---|---|
NSW | 8.0 | 8.1 | 7.6–8.6 |
Vic | 9.3 | 8.9 | 8.4–9.5 |
Qld | 9.2 | 9.0 | 8.4–9.7 |
WA | 9.7 | 9.3 | 8.4–10.3 |
SA | 8.9 | 9.1 | 8.1–10.1 |
Tas | 8.9 | 8.7 | 7.1–10.5 |
ACT | 7.9 | 7.1 | 5.4–9.3 |
NT | 6.4 | 6.2 | 3.3–10.5 |
Australia | 8.8 | 8.7 | 8.4–9.0 |
Note: Age‑standardised (AS) rate is the number of interval cancers detected per 10,000 person-years, age‑standardised to the population of participants attending a BreastScreen Australia service in 2008; ‘95% CI’ are 95% confidence intervals.
Source: AIHW analysis of BreastScreen Australia data.
State and territory | Crude rate | AS rate | 95% CI |
|---|---|---|---|
NSW | 8.1 | 8.1 | 7.7–8.6 |
Vic | 9.3 | 9.1 | 8.5–9.6 |
Qld | 9.1 | 9.0 | 8.4–9.6 |
WA | 10.0 | 9.7 | 8.9–10.6 |
SA | 8.8 | 9.0 | 8.0–9.9 |
Tas | 8.9 | 8.7 | 7.2–10.4 |
ACT | 7.8 | 7.1 | 5.5–9.1 |
NT | 6.6 | 6.6 | 3.9–10.5 |
Australia | 8.9 | 8.7 | 8.5–9.0 |
Note: Age‑standardised (AS) rate is the number of interval cancers detected per 10,000 person-years, age‑standardised to the population of participants attending a BreastScreen Australia service in 2008; ‘95% CI’ are 95% confidence intervals.
Source: AIHW analysis of BreastScreen Australia data.