Re: "Overmatching" Controls?! (Radon Medicine Efficacy)

[epirad@mchsi.com]

Howard, 



Please read the study Mr. Muckerheide posted concerning 

the problems with over matching in a case-control study.



Howard, it is really not my position to accept the 

ethics, that would be up to the Human Subjects Internal 

Review Board at the facility where such a study would be 

performed.  I would not have to sign on for the study to 

take place.  It may be helpful to identify the rate 

limiting steps that prevent the funding of such a 

study.  



My criticism of your proposal is more a matter of 

reality.  It would be impossible to perform a placebo 

controlled study of radon in the general population.  



The multivariate analyses performed in case-control 

studies has tremendous power to adjust for smoking and 

other potential confounders since data is collected at 

the level of an individual. 



Bill

> Bill, Bernie, rad scientists and HPs,

> Radon, like all other MEDICINES, must be tested with maximum matching

> possible (placebo-controlled studies, double blinded), to definitively

> identify most beneficial dosage, frequency of bad results (unusual

> sensitivity), etc.

> 

> Why does Field refuse to accept the ethics of such a study? In Iowa,

>  37% smoking "matched controls" (for 87% smoking lung cancer cases),

> elicits incredulity about the validity of  "statistical correction".

> True controls must be identical to cases in everything except the

> chemical being tested, even to placebo effect (usually 30%).

> 

> Cohen is correct here. Field refuses for radon, a test required of every

> other medicine.

> 

> Howard Long

> 

> epirad@mchsi.com wrote:

> 

> > yes, I spoke on Radsafe about this before.

> >

> > http://www.vanderbilt.edu/radsafe/0005/msg00861.html

> >

> > http://www.vanderbilt.edu/radsafe/0201/msg00601.html

> >

> > Also, see:

> > http://www.vanderbilt.edu/radsafe/0006/msg00593.html

> >

> > Dr. Cohen States: "The basis for a case-control study is

> > that cases and controls are matched in every way except

> > for having contracted the disease. Any deviation from

> > this would seem to be an issue for concern."

> >

> > Field: This is an erroneous statement. What Dr. Cohen

> > describes here is OVERMATCHING. Dr. Cohen says in a case-

> > control study the cases and controls are matched "in

> > every way except for having contracted the disease". Dr.

> > Cohen, I respectfully request a reference for this

> > statement. For example, if your statement was true, we

> > should have matched the cases and controls by radon

> > concentration, mobility, shoe size, eye color, favorite

> > ice cream flavor, etc.

> >

> > > Friends,

> > >

> > > Have you reviewed the paper below on case-control

> > study over-matching error?

> > >

> > > Comments?

> > >

> > > Regards, Jim Muckerheide

> > > ========================

> > >

> > > Removal of radiation dose response effects: an example

> > of over-matching.

> > > Marsh JL, Hutton JL, Binks K.

> > > Department of Statistics, University of Newcastle upon

> > Tyne NE1 7RU

> >

> > _______________________________________________

> > rad-sci-l mailing list

> > rad-sci-l@ans.ep.wisc.edu

> > http://ans.ep.wisc.edu/mailman/listinfo/rad-sci-l

> 

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

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/