Patient Outcomes from Second Film-readers and Test Threshold Relaxation in Breast Screening

Patient Outcomes from Second Film-readers and Test Threshold Relaxation in Breast Screening: an Observational Retrospective Cohort Study

Analysis of women's medical records to understand the impact of previous changes to breast cancer screening (increase from one to two clinicians examining each woman's mammograms, and what proportion of women they recall for further tests)

Retrospective observational study examining the records and outcomes of women who attended breast cancer screening between 1988 and 2016. Linkage of records from the breast screening service, the cancer registry, and mortality. Analysis of whether changing the threshold for whether to recall women for further tests or the number of clinicians examining the mammograms for signs of cancer affects outcomes.

Inclusion Criteria:

• Women who attended the English National Health Service (NHS) breast cancer screening service at least once between 1988 and 2016, aged between 47 and 73
• All eligible episodes of screening for each woman (we expect women to be screened around 7 times each)

Exclusion Criteria:

• Women who did not attend routine English NHS Breast screening service within the specified date and age range, even if they attended symptomatic breast cancer services, high risk (family history) breast screening services, or if they were referred for mammograms by their general practitioner