Breast cancer mortality in unscreened women [posted as suppled by author]

Breast cancer (BC) mortality in unscreened women was calculated as
 

BC mortality_unscreened = Total BC mortality_{(unscreened+screened)} / (proportion of population_unscreened+ RR* x proportion of population_screened)
 

* relative risk of breast cancer mortality as described under Mortality benefit of screening.
 

We verified the calculated breast cancer mortality rates against population rates reported by the

Australian Institute of Health and Welfare in 1987-1991, ie in the years prior to screening.