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RE: Ecologic versus case-control

<Agreement is ok on the principle, but each study must be judged also on
how it reflects the relevant science, both statistics and biology. Cohen
has several hundred independent studies, plus many independent studies
with the same results. Radon case control studies don't. The Iowa study
isn't confirmed, and the poor quality of the data and the poor
statistics establishes clearly that it is most likely that a replication
of the study would produce a significant departure from the current
result. (Could argue that it could go either way, but in fact, such
errors tend toward the null, so it is more likely to go in that
direction.) In addition they are contradicted by the biology and
medicine evidence we do have.

Jim, 

Well I thought we had some agreement.  Could you be a little clearer in your assertion that Cohen has several hundred INDEPENDENT studies?  How do you arrive at this?

What study are you referring to that has poor statistics, please be precise in describing why you think either the statistics or methodology is poor.  You previously have stated that the best residential radon study was the China residential radon study.  Can you tell me specifically why you think that study was a good study.  Did you base your opinion on the findings of that study?

You agreed that a well designed case-control study is better than a well designed ecologic study for assessing risk.  Could you tell me how you would design a residential case-control study that would meet your approval?

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<Right. Radon case-control studies don't know actual exposures. That
substantially limits their so-called case-control advantage in
principle. Have no longer removed the most significant variable, but
left with a small group with no constraints.>

Jim, the exposure is known in a case-control study like the one we performed for each individual.  Can you tell me ANY ecologic study where you know the actual exposure for even one person?


Jim, here you go back (below) criticizing the agencies.  The EPA or DOE did not sponsor any of the American residential radon studies, so what does this have to do with their interests?  What grounds do you have for this view against the DOE and EPA?  What impact do they have in regard to what the NIH funds?    Jim, the issue is in the quality of the data first and then the statistical analyses.  If you do not have good data, why even perform the analyses except for ecologic studies where the county averaged data is collected easily from existing sources and are fairly cheap to perform. 


 
<Here you go back to semantics instead of science. The issue is only in
the quality/validity of the statistics. Here it is very important that
replications and confirmatory studies address the possibility that a
bias could exist in a single study that does not have individual
consequences.  But arguing that ALL the consistent results of
independent studies have the same error is equivalent to arguing that it
is possible that materials in macroscopic quantities will likely
accelerate upward due to the brownian motion all atoms going "up" at the
same time! It's not going to happen. But that doesn't keep Samet et al.
from arguing it on behalf of their sponsor interests at EPA, DOE, etc.>
 
Regards, Jim
 
 
If the ecologic data is very accurate and you know there is no
cross-level bias or other non linear dependent factors, an ecologic
study can be very accurate on the aggregate level.

Bill

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