Cumulative attendance, assessment and cancer detection rate over four screening rounds in five English...

Data collection in the National Health Service Breast Screening Programme monitors performance in a different cohort of women each year.

This paper follows a single cohort study of 57,425 women (aged 50-53, when first invited) over four screening rounds to find: how many women attend screening and how often; how many were assessed; how many times they were assessed; and the number of cancers detected at each round.

Average attendance in each round was 76.9% and has remained constant. Only 62% of women have attended all four rounds, but 89.9% have been screened at least once, the average number of attendances being 3.5. Average assessment rate decreased from 7.3 to 3.5%. A total of 11.3% of women were assessed once, 0.91% twice and 0.06% three times. Cancer detection rates have more than doubled from 3.3 per 1000 screened to 6.9.

Current monitoring shows constant uptake over time, but when looking at a cohort of individual woman, a much larger percentage have 'ever' attended and a smaller number have attended all invitations. The chance of a woman being assessed at all, if she attends all four rounds, is 12.3%, which can be calculated by summating the recall rates in each round.