Thursday, November 19, 2009

Innumeracy and Mammograms

Quite a bit of heat, but little light, has come from the government's recent declaration that yearly mammograms are no longer necessary for women under fifty. Neither side has shown any numbers defending or attacking the proposition. How about some graphs showing deaths from breast cancer over the years, number of breast removals, number of less drastic treatments, survival rates after treatment, number of mammograms administered, number of false positives for mammograms, false positives from breast self examination, number of breast cancers detected by mammograms, number detected by other means.
The proposition that yearly mammograms after age 40 saves lives, and/or reduces breast removals, is a numerical proposition, and the advocates on either side could strengthen their arguments with some numbers. If the numbers cannot be found, perhaps a study could be funded.
So far the public debate has been number free.
Probably because reporters are innumerate.

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