Re: Mr. Ford and Iowa Radon Lung Cancer Study

[Ted de Castro <tdc@XRAYTED.COM>]

2 of Mr Ford's questions were EXACTLY the ones that I have been

struggling over and over with while reading this thread.  Sorry - but I

still have problems with one you answered - and one you didn't:



"Field, R. William" wrote:

> studies must adjust for smoking.  This is a routine process.  The more

> you match, the more you get away from a population-based study. It is

> not smoke and mirrors, but it would likely take you several semesters

> of statistics and epidemiology to understand how it is done.  In the

> Iowa study, we also performed checks for residual confounding from

> smoking and no residual confounding was noted.



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.



Lastly - the point not addressed - was the apparently absolute

confidence in the accuracy of personal interviews.  Leaving out that

people may somewhat underplay their frequency of a bad habit ---- beyond

that almost everyone here I'd bet had done personal interviews to track

down the cause of a dosimeter reading.  In the days of monthly

dosimeters this was difficult enough - now with quarterly changeouts -

its become nearly impossible to get an accurate assessment of activities

of a 3 month interval that began 4 months ago.  Based on this experience

- I personally would place VERY LARGE error bars on decades of

recollection!  Now if they had kept a log - that would be one thing -

but recollection? - It is hard to believe.

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