Participation rate

The participation rate tells us what proportion of people who are eligible for breast cancer screening have been screened within guidelines. Factors that influence the participation rate include the availability of routine mammography or opportunistic screening; acceptability, accessibility and promotion of screening programs; and recruitment strategies. Provinces and territories use a variety of strategies to recruit screening participants.

Why is this important? High participation in breast cancer screening programs not only reduces breast cancer morbidity and mortality in the eligible population, but also increases the efficiency of screening programs.1 This indicator tells us how many people who are eligible for breast screening are indeed participating in the breast screening program.

Indicator definition: The percentage of the target population who have a breast cancer screening within a 30-month period.

Target: ≥70% of the target population within a 30-month period

Measurement timeframe:

  • January 1, 2018 to June 30, 2020
  • January 1, 2020 to June 30, 2022

Six months was added to each standard two-year screening period to allow a grace period for participants to complete their screen following their two-year screening anniversary date.

Indicator calculation:

  • Numerator: The number of participants who had at least one breast cancer screen in the measurement timeframe.
  • Denominator: The target population aged 50-74 at the end of the measurement timeframe. Exclusions:
    • Participants with previous bilateral mastectomy
    • Previous diagnosis of breast cancer

Breast cancer screening participation among individuals aged 50-74, who were screened within a screening mammography program, by jurisdiction and screening period – 2018-19 and 2020-21

*The orange bar for QC indicating that the participation rate was 59.7% represents 2019-20 data, rather than 2020-21.
Data table and footnotes

In both 2018-19 and 2020-21, screening participation rates in all jurisdictions were below the Canadian target of ≥70%. The 2018-19 participation rates ranged from 35.0% in Newfoundland and Labrador to 65.6% in Quebec. In comparison, participation rates in 2020-21 were lower in most jurisdictions, given the impact of the COVID-19 pandemic, with rates ranging from 28.4% in Saskatchewan and 54.9% in Ontario.

Breast cancer screening participation among individuals aged 50-74, who were screened within a screening mammography program, by jurisdiction and age group – 2018-19 and 2020-21

Data table and footnotes

In most jurisdictions, participation rates slightly decreased (worsened) across all age groups in 2020-21 compared to 2018-19. In Northwest Territories, however, participation rates in 2020-21 increased in the 60-69 age group (from 40% to 58%) and 70-74 age group (from 29.6% to 54.5%). In all jurisdictions, the 60-69 age group was observed to have the highest participation rates in 2020-21.

  1. Mandrik O, Tolma E, Zielonke N, Meheus F, Ordóñez-Reyes C, Severens JL, Murillo R. Systematic reviews as a “lens of evidence”: Determinants of participation in breast cancer screening. J Med Screen. 2021 Jun;28(2):70-79. doi: 10.1177/0969141320930743. Epub 2020 Jun 9. PMID: 32517538; PMCID: PMC8167916.