Re: Linear Model

[gr_cicotte@ccmail.pnl.gov]

          I'm a bit confused.  I'd have to go back and look at the 
          literature to be sure, but it was my recollection that the 
          Japanese survivor data was used to determine that we didn't know 
          enough about low doses to be sure, but that it was linear at 
          higher doses, so we would use that at low doses.  I think many 
          of us forget that the no-threshold concept is not a theory, but 
          merely an administrative measure taken many years ago to cover a 
          LACK of science.  It has been caught up by the public, press, 
          and lawmakers as being part of the science, which the scientists 
          involved never asserted it to be.
          
          On that basis, I would have to dispute the issue that the linear 
          model and the "no threshold" corrollary thereto are BOTH 
          developed from the Japanese survivor data.  Also, the two 
          demographic groups (Cohen's subjects and the Japanese), while 
          having in common the fact that they encompass small geographic 
          regions, are sufficiently different to draw no conclusion 
          regarding relative "ecological fallacy" between the two.  The 
          epidemiology is based on vastly different exposures.  While it 
          may in fact be true regarding the Japanese data, as it has been 
          asserted regarding Cohen's data, I do not believe there has been 
          sufficient correlation between the two to draw any such 
          conclusion.
          
          Please correct me if I'm wrong (preferably unflamed).
          
          V/R
          George R. Cicotte
          Research Engineer
          HEALTH PROTECTION DEPARTMENT
          Battelle Pacific Northwest Laboratory.
          


______________________________ Reply Separator _________________________________
Subject: Linear Model
Author:  HWADE@aol.com at -SMTPlink
Date:    8/8/95 12:41 AM


1. Cohen's 1995 paper answers the previous criticisms that the "ecological 
fallacy" marred its conclusions. HP,v68,no.2.
Therefor, previous criticisms are no longer valid
2. Cohen has now completed a case-control study that shows a negative 
correlation between radon concentration and case-control ratio. Annual 
Meeting abstracts, HP,supp to v68, no.6.
3. The Japanese data are subject to the same "ecological fallacy" as other 
studies, yet we seem to be able to accept them, and indeed use them to build 
a case for linearity.
4. The paper by the IARC study group on cancer risk among nuclear industry 
workers, Lancet, 344:1039;1994 fits the data to a linear model and therefor 
cannot be used as an argument for the validity of the linear model. (not 
unless you believe one can pull himself up by tugging on his bootstraps.)