Reply to: Loss of QALY in mammography screening reported by Zahl et al.

In their letter, Njor and Lynge argue that mammography screening leads to 5% overdiagnosis and 20% reduction in breast cancer mortality and assume that all translates to reduced overall mortality. Njor et al. base their estimates on their own studies only,1, 2 and ignore other more comprehensive studies from Denmark.3, 4 Njor et al. included only 8% (57,763) of the available female Danish population when studying overdiagnosis.1 A later study...