Re: Cancer clusters

[Brian Rees <brees@LANL.GOV>]

Wouldn't that result in 20 more opportunities for funding?

Maybe it isn't an understanding in epi that was lacking!



(Obviously) my personal opinion - on a Friday to boot.

Brian Rees



At 10:53 AM 7/19/2002 -0600, Kai Kaletsch wrote:





>I was involved in a study once where a cohort was supposed to be followed

>for some 40 years to see if there was an increase in lung cancer. Apparently

>this was a little boring for the lead epidemiologist and she suggested that

>we look at other outcomes as well (ones where there was no a priory

>suspicion that they were connected with the substance under investigation).

>She further suggested that we didn't have to wait for 40 years, we could

>check the data before and we could publish results at any time that we found

>something.

>

>If you check for 20 outcomes at 20 time intervals (400 combinations) and

>used an alpha of 0.05 you would have 20 false positives from just the one

>study. (Yes, I know the 400 combinations are not independent, but its close

>enough.) A few of us who had a more fundamental understanding of statistics

>objected to this, but the lead epidemiologist insisted that this was

>standard practice and we didn't know anything about epidemiology.

>

>Kai



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