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Re: Mr. Ford and Iowa Radon Lung Cancer Study









>From: Ted de Castro <tdc@XRAYTED.COM>

>I am having trouble with this - I don't see that it matters that the

>mathematical correction is a "common" or "standard" practice of

>"correction" - THAT claim does not speak to its precision or accuracy.

>I find it hard to fathom that medical science knows the relationship

>between smoking and lung cancer well enough to reduce it to a

>mathematical formula - let alone a formulation so accurate and precise

>that it can be used to correct an overwhelming confounder (small errors

>with a correction of a large number will allow large errors in the

>assessment of a smaller number).  It is hard to accept.





Ted, I think the point he was making was that it is not that uncommon to do 

this in everyday practice.  It is not a matter of medical science 

understanding it, it is a matter of whether or not smoking can be modeled 

accurately for the subjects.  This modeling can take a week or so to perform 

using standard techniques of multivariate regression.  Just because it is 

standard does not mean it was done correctly.  But looking at who the 

statisiticians were gives me confidence it was done correctly.



Besides they looked for residual confounding and did not find any.



http://www.public-health.uiowa.edu/faculty/~woolson.html



It was my understanding the retrospective recall was based on life events.  

People know when they had kids, worked, were at home, etc.



Don



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