Table 4.

Sensitivity of screening in the Age trial and in the models.

	First screen (two view mammography)	Subsequent screens (single view mammography)
Age trial	73.6	55.2
Model D	73.6	55.3
Model E	72.5	55.7
Model M*	-	-
Model S	75.5	59.0
Model W	67.7	59.6

^*Model M is a Bayesian without a natural history part and a woman’s disease status is unknown. As a result sensitivity is not applicable. Model M simulates screen- and clinically-detected incidences without knowing the true disease status.

Sensitivity of screening and screen detection is modeled differently in various models. In the continuous tumor growth models E, S, and W screen detection of tumors is simulated by transforming sensitivity to a threshold tumor size at which tumors can be screen detected. On the other hand, model D uses sensitivity of screening by simulating a shift to a less-advanced stage of breast cancer.