Re: New Steve Wing Study

["Gibbs, S Julian" <s.julian.gibbs@vanderbilt.edu>]

I think we are being overly critical of epidemiological 
studies.  Some have been quite helpful.  Remember that the 
early reports linking smoking and lung cancer were 
epidemiological.
We must also remember that these case-control studies 
merely show an association.  They do not demonstrate cause 
and effect.  For example, it is well known that the 
carcinogenic process may take years to decades.  These 
studies linking low-dose radiation with cancer could then 
be interpreted that beginning cancers cause people to seek 
low-dose (e.g., occupational) radiation exposures.  
Patently absurd but it fits the data.
I am not trying to defend obviously flawed studies, such 
as the one that generated all this discussion. They are 
numerous in the literature. But we must not throw the baby 
out with the bathwater.

***********************************************************
S. Julian Gibbs, DDS, PhD               Voice: 615-322-3190
Professor of Radiology                    FAX: 615-322-3764 
Dept. of Radiology & Radiological Sciences
Vanderbilt University Medical Center
Nashville TN 37232-2670 Email:s.julian.gibbs@Vanderbilt.Edu