Participation rate in breast cancer screening program
The results were extracted from figure 3B in the report: Breast Cancer Screening in Canada: Monitoring and Evaluation of Quality Indicators – Results Report, January 2011 to December 2012. Details on methodologies can be found in the report.
Abnormal call in subsequent screening mammograms
Definition: Percentage of subsequent screening mammograms that are identified as abnormal in women aged 50-69
Rationale for measurement: Abnormal call rate is an important indicator of the quality of the mammography image and interpretation. A high abnormal call rate can increase the false positive rate and result in unnecessary (and potentially avoidable) tests. Programs should strive to balance the number of abnormal calls with the number of cancers detected. This can be monitored by comparing the number of abnormal screens per extra cancer detected. Programs with extremely low abnormal call rates should also be monitored as this may results in lower cancer detection and higher post-screen cancer rates.
Measurement timeframe: Screening years 2003 to 2012
Denominator: Number of subsequent screening mammograms during the timeframe in women aged 50-69
Numerator: Number of subsequent screening mammograms identified as abnormal in women aged 50-69
Exclusion criteria:
- Women with ages beyond 50-69
- Cases referred by clinical breast exam (CBE) alone
- Women new to the screening program
Data availability: All provinces and NT
Stratification: By years
Data source: Canadian Breast Cancer Screening Database
Data retrieval date: Mar 2016
Variables details: Not applicable
Notes from jurisdictions:
- AB: Excluded from data prior to 2007 as the Alberta Breast Cancer Screening Program was launched in 2007.
- QC: Complete diagnostic/cancer information was available to September 30, 2012.
Methodology notes: Analysis was conducted by Public Health Agency of Canada (PHAC).
Changes to definition compared to previous years: Not applicable
Invasive cancer detection in subsequent screening mammograms
Definition: Invasive breast cancer detection rate (per 1,000 screens) in women aged 50-69 through subsequent screening mammograms
Rationale for measurement: The cancer detection rate is to evaluate how successful the program is at finding invasive cancers. It is also meaningful when considered in relation to the abnormal call rate.
Measurement timeframe: Screening years 2003 to 2012
Denominator: Number of subsequent screening mammograms during the timeframe in women aged 50-69
Numerator: Number of invasive breast cancer detected in subsequent screening mammograms in women aged 50-69
Exclusion criteria:
- Women with ages beyond 50-69.
- Cancers detected by clinical breast exam (CBE) alone
- Women new to the screening program
Data availability: All provinces and NT
Stratification: By years
Data source: Canadian Breast Cancer Screening Database
Data retrieval date: Mar 2016
Variables details: Not applicable
Notes from jurisdictions:
- AB: Excluded from data prior to 2007 as AB Breast Cancer Screening Program (ABCSP) launched in 2007
Methodology notes: Analysis was conducted by Public Health Agency of Canada (PHAC).
Changes to definition compared to previous years: Not applicable