Rejection of possible explanation for Cohen's results

[FIELDRW@aol.com]

In a message dated 00-03-09 10:09:14 EST, Cohen wrote:

<<  Field Response: As we suggested before (see references below), the risk 
model 
 > you derive from the BEIR IV model is not equivalent to the BEIR IV risk 
 > model.  You attempted to equate the model to the BEIR IV model by applying 
 > rigid assumptions that include: 1) The time spent in the home is the same 
for 
 > all individuals; 2) radon exposures occurring outside the home do not 
 > contribute to lung cancer risk; 3) baseline lung cancer mortality is 
solely a 
 > function of age and smoking; 4) all smokers have the same increased risk 
of 
 > mortality; 5) smoking duration and intensity is the same for everyone; 6) 
age 
 > is the only modifying effect of radon exposure; and 7) radon concentration 
is 
 > directly proportional to the delivered dose from the radon progeny.
 
    --Anyone with experience in mathematical derivations will
 recognize that it would be impossible to take every little possible
 complicating detail into account in a mathematical derivation. All of
 these issues have been addressed elsewhere in my publications. Items 1, 2,
 and 7 were addressed in Table 1 and associated discussion in my paper in
 Health Physics 75:23-28;1998. Item 4 is the assumption of BEIR-IV that I
 was starting with. Item 5 is most fully analyzed in two forthcoming papers
 accepted for publication in Health Physics and J. Radiol Prot. These also
 cover Item 4. Items 3 and 6 are covered by my responses to the other
 items. 
    Can you explain how these problems are handled in case-control
 studies?  >>
---------------------------

Dr. Cohen,

As time permits, I would be very happy to work on a joint paper with you to 
discuss how these factors are taken into account in a case-control studies 
versus ecologic studies.  Let me know if you are interested. The paper below 
touches on how these questions are addressed in a case-control study.

Field, R.W., Steck, D.J., Lynch, C.F., Brus, C.P., Neuberger, J.S., Kross, 
B.C., Residential Radon-222 Exposure and Lung Cancer: Exposure Assessment 
Methodology.  Journal of Exposure Analysis and Environmental Epidemiology, 
6(2): 181-195, 1996. 

Dr. Cohen you stated:  I can not expect you to take every little possible 
complicating detail into account in a mathematical derivation.

Some of these little complicating details could explain the results you get.  
I do expect you to at least provide (peer reviewed papers) references to 
support your assumptions.  This is part of the scientific method. You have 
yet to provide references to support any of your primary or secondary 
assumptions for your derivations.

You asked people to submit questions, I am confused why you would try to 
reject my question by saying I expect too many details.    
 
Bill Field
Bill-field@uiowa.edu
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