Effects of lead time, length bias, and false‐negative assurance on screening for breast cancer

This article presents a model of breast cancer screening programs. The model shows the effects of the screening threshold, screen sensitivity, and false‐negative assurance on the cumulative mortality rate in the screened population. It shows that factors of screen design and a penalty associated with false‐negative assurance can result in excess mortality rates in screened populations‐especially in those age classes in which the incidence of rapidly growing tumors is high. Factors related to the magnitude of this effect are described.