From: Breast cancer screening: evidence of benefit depends on the method used
 | Years included in study | Year of screening introduction in screening areas | Age groups | BC mortality rate in the pre-screening period (historical control) | BC mortality rate in the screening period | Ratio of BC mortality rates, screening versus pre-screening perioda | Ratio of BC mortality rates, screening versus non-screening areasa |
---|---|---|---|---|---|---|---|
Screening areas | Â | Â | Â | No screening | Screening | Â | Â |
Denmark, Olsen et al. 2005 [28] | 1981 to 2001 | 1991 | 50 to 79 | 69 | 52 | 0.75 | 0.74 |
Norway, Kalager et al. 2010 [33] | 1986 to 2005 | 1996 | 50 to 84 | 33 | 24 | 0.73 | 0.9 |
Norway, Olsen et al. 2012 [34] | 1990 to 2008 | 1996 | 50 to 84 | 35 | 27 | 0.77 | 0.91 |
Comparison (non-screening) areas | Â | Â | Â | No screening | No screening | Â | Â |
Denmark, Olsen et al. 2005 [28] | 1981 to 2001 | - | 50 to 79 | 52 | 53 | 1.02 | reference |
Norway, Kalager et al. 2010 [33] | 1986 to 2005 | - | 50 to 84 | 31 | 25 | 0.81 | reference |
Norway, Olsen et al. 2012 [34] | 1990 to 2008 | - | 50 to 84 | 39 | 33 | 0.85 | reference |