Does Lea Time Bias Work?

Lea time bias is the idea that when you are screening to identify cancer, if you screen and find a cancer earlier than that cancer would have been diagnosed based on symptoms. The reason people call it lee time bias is because if you measure survival from the time of diagnosis, that can be misleading. A famous study published in the newenglan derla medicine looked at about 50 thousand people who were at high risk for lung cancer. They randomized them to one of two screening approaches.