Analysis of attendance and screening variation in a UK breast cancer screening unit

The United Kingdom was reported in 1999, as the country with the third highest breast cancer death rate in the world. Nevertheless, the UK mortality has been falling dramatically since 1989. The country commenced implementation of a triannual National Breast Screening programme in 1987. A national programme is expected to start delivering mortality reductions after 5-7 years from full implementation. Successful mortality reductions are related to the performance of the screening test and rate of attendance for screening (compliance). The present work is focused on a statistical descriptive analysis of the attendance and screening variation of women invited for the preventive screening programme in a district based breast cancer-screening unit. The analysis includes appointments since 1989 from a data set of 147,432 women. Data was restricted to non-symptomatic women invited to screening. The unit has run up to four episodes achieving a screening of 80.6% of the invitations. An increase in the cases with screening variation has been observed as the number of episodes increased. However, and despite that, 99% of the women who attended for screening did so within 3 months of their initial invitation