Effect of organized mammography screening on breast cancer mortality: A population-based cohort study in Norway

We aimed to estimate the effect of organized mammography screening on incidence‐based breast cancer mortality by comparing changes in mortality among women eligible for screening to concurrent changes in younger and older ineligible women. In a county‐wise balanced, open‐cohort study, we used birth cohorts (1896–1982) to construct three age groups in both the historical and screening period: women eligible for screening, and younger or older...