Breast screening in Canada, 2023-24
Strategies to reach the abnormal call rate target
The abnormal call rate (ACR) — the percentage of mammograms identified as abnormal — is a key quality indicator of breast screening programs. In Canada, an increase in ACR without any corresponding increase in the cancer detection rate has been observed. Improving ACRs could minimize potential harms from over-screening and avoidable follow-up tests to ensure the benefits of screening are maintained.
Efforts have been made in Canada to support programs in optimizing their ACR. In 2020, the Partnership released the Pan-Canadian Framework for Action to Address Abnormal Call Rates in Breast Screening, which outlined a number of strategies to optimize ACR.
Strategies to optimize the abnormal call rate
| P/T | Min. reading volume | Double reading | Audit and performance feedback | Comparisons with prior mammogram | Number of mammo-graphic views | Mammo-graphic compression | Batch reading of mammogram | Fellowship training in breast imaging |
|---|---|---|---|---|---|---|---|---|
| YT* | ||||||||
| NT | ✓ | ✓ | ✓ | ✓4 | ✓ | |||
| NU | – | – | – | – | – | – | – | – |
| BC | ✓ | ✓ (performance feedback stats modified to highlight areas of opportunity for improvement) | ✓ | ✓4 | ✓ | |||
| AB | ✓ | ✓ (varies by clinics) | ✓ (intend to explore) | ✓4 | ✓ (intend to explore) | ✓ (varies by clinics) | ||
| SK | ✓ | ✓ (modified^) | ✓ (intend to enhance) | ✓ | ✓4 | ✓ | ✓ | ✓ (some rads, not all) |
| MB | ✓ | ✓ | ✓ | ✓4 | ✓ | ✓ | ✓ (some rads, not all) | |
| ON | ✓~ | ✓ | ✓ | ✓4** | ✓ | ✓ (encouraged at the site level) | ✓ (some rads, not all) | |
| QC | ✓ | ✓ | ✓ | ✓ 4 | ||||
| NB | ✓ | ✓ | ✓ | ✓ | ✓4 | ✓ | ✓ (may vary by screening site) | |
| NS | ✓ | ✓ | ✓ | ✓ | ✓4 | ✓ | ✓‡ | |
| PE | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ (encouraged at the site level) |
✓ (some rads, not all) | |
| NL | ✓ | ✓ | ✓ | ✓4 | ✓ | ✓ (some rads, not all) |
*YT: Mammograms are read remotely by radiologists in jurisdictions outside of the territory (e.g., BC, AB, ON)
^SK: Experienced technologists review all images prior to initial read, and discrepancies are reviewed by second radiologist if needed.
~ON: The OBSP is aligned with the CAR MAP requirement for radiologists to report a minimum of 1,000 reads per calendar year.
**ON: Four additional views (implant displacement views) required for people with breast implants.
‡NS: Some radiologists have fellowship training in breast imaging.
-NU: No information was provided at the time data were collected.