Epi studies

["Tony Harrison" <Tony.Harrison@state.co.us>]

Dr. Kenneth J. Rothman ( Modern Epidemiology; Little, Brown & Co.,

Boston, 1986) classifies epidemiologic studies as experimental or

nonexperimental.  Experimental sudies include clinical trials, field

trials and community intervention trials.  Nonexperimental studies

include follow-up or prospective cohort studies, case-control studies

and ecologic studies.  Experimental studies are able to demonstrate

cause-effect or dose-response relationships better than non-experimental

ones.  Of the non-experimental type, cohort studies are best able to

suggest (not prove) a dose-response effect, and ecological studies are

the least able.  



With due respect to Dr. Cohen, I don't understand how one can test the

LNT without making some estimate of risk to individuals, something that

ecologic studies are pretty much incapable of.





Tony Harrison, MSPH

Colorado Dept. of Public Health & Environment

Laboratory and Radiation Services Division

(303)692-3046

tony.harrison@state.co.us





>>> "Carl Miller" <radprot@mad.scientist.com> 05/05/03 11:04AM >>>



----- Original Message -----

From: "Otto G. Raabe" <ograabe@UCDAVIS.EDU>

Date: Fri, 02 May 2003 15:32:42 -0700

To: BERNARD L COHEN <blc+@PITT.EDU>

Subject: Re: NCRP bias?

> 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,



I think ecologic studies are also considered epidemiology studies. 



Also, I think it has been pointed out on this list, before that Dr.

Cohen fails to consider the interaction between all the colinear factors

that can work together such as smoking, education, and socioeconomic

status at one time.  These factors are very inter related and Dr. Cohen

looks at his potentially confounding factors in a univariate manner

rather than a multivariable manner which would be required to capture

the effect.  



Dr. Cohen may not think it is plausible to explain his findings just by

his use of guestimated county smoking rates(which are inversely related

to the radon), but what about the co-linearity between smoking,

education and socioeconomic factors? Dr. Field has pointed this out

before.



In addition, I think it was Drs. Lubin and Field that showed when

better data was for lung cancer incidence the inverse assocaition was

not found in Iowa (a s tate with high radon).  Dr. Cohen has never

explained this finding in a satisfactory manner. 





-- 

__________________________________________________________

Sign-up for your own FREE Personalized E-mail at Mail.com

http://www.mail.com/?sr=signup 



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

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/





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

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/