Re: NCRP bias?

["Otto G. Raabe" <ograabe@UCDAVIS.EDU>]

At 09:25 AM 5/2/03 -0400, BERNARD L COHEN wrote:

>

>I recognize that to many

>epidemiologists it is a religious conviction that an ecological study

>cannot be used to test a theory, but the NCRP committee includes

>physicists who should not be influenced by that religious conviction.

**************************************************

May 2, 2003



A few years ago Bernie Cohen and I were invited to attend a committee

hearing on LNT at the NCRP headquarters in Bethesda. At that meeting, we

watched as Jay Lubin derived on the board the mathematical relationships

associated with possible slope observations in an ecological study such as

Bernie's and showed convincingly that unrecognized and possibly

undetectable cross-interactions between the variables could result in a

completely meaningless "observed" regression slope irrespective of the

underlying true relationship. Hence, it is a mathematical truth (not a

religious conviction) that the "observed" slope in Bernie's study of the

possible relationship for radon-induced lung cancer could be totally

spurious. On the other hand, this is not a proof that it is necessarily wrong.



It seems to me that all Bernie has been asking for is a plausible

suggestion as to what conceivable or even far-fetched cross interaction is

yielding his robust results.



Otto  

**********************************************

Prof. Otto G. Raabe, Ph.D., CHP

Center for Health & the Environment

(Street Address: Bldg. 3792, Old Davis Road) 

University of California, Davis, CA 95616

E-Mail: ograabe@ucdavis.edu

Phone: (530) 752-7754   FAX: (530) 758-6140

***********************************************

************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/