You have the right to remain anxious....

"It's extremely hard not to have a diagnosis," according to Steve Woloshin, this week at the 2012 NIH Medicine in the Media course for journalists. Allen Frances talked about over-diagnosis of mental disorders (read more about that in my blog at Scientific American online).

The National Cancer Institute's Barry Kramer tackled the issue of over-diagnosis from cancer screening. He explained lead-time bias using an image of Snidely Whiplash tying someone to train tracks. Ineffective screening, he said, is like a pair of binoculars for the person tied to the tracks: you can see the train coming at you sooner, but it doesn't change the moment of impact.

Survival rates after a screening diagnosis increase, even when no one lived a day longer: people have cancer for longer when the diagnosis comes long before any symptoms. Screening is effective, on the other hand, when earlier detection means more people do well than would have done if they'd gone to the doctor first when there were symptoms.


Read more in The Disease Prevention Illusion: A Tragedy in Five Parts