Changes in Canadian women's mammography rates since the implementation of mass screening programs

Objectives. This study reports on Canadian mammography rates between 1990, when mass screening programs were launched, and 1994/95. Methods. Mammography rates from 2 national surveys were compared according to the presence of a provincial screening program. Results. Mammography rates among women aged 50 to 69 years (the targeted group) increased significantly, by 16%; increases were twice as high in provinces with screening programs, Among women in their 40s (nontargeted group), the changes were insignificant and independent of screening program status. Conclusions. Screening programs appear to have influenced the mammography rates of targeted women aged 50 to 69 years.