Ecologic Limitations

From: Muckerheide <muckerheide@MEDIAONE.NET>

The primary factor in a 'case-control' study is knowing the dose to

the

individual. Radon case-control studies do NOT know the dose to the

individual.

Jim,

PLEASE take the time to learn the limitations of the various

epidemiologic designs. I know of no credible, published

epidemiologist that seriously considers Cohen's finding plausible.

For example, Jay Lubin pointed out that "There is still substantial

confusion in the radiation effects community about the inherent

limitations of ecologic analysis. As a result, inordinate attention

has been given to the discrepant results of Cohen, in which a

negative estimate is observed for the regression of county mortality

rates for lung cancer on estimated county radon levels. Since adverse

effects for radon at low exposures are supported by analysis of miner

data (all data and data restricted only to low cumulative exposures),

a meta-analysis of indoor radon studies, and molecular and cellular

studies, and since ecologic regressions are burdened by severe

limitations, the negative results from Cohen's analysis are most

likely due to bias and should be rejected."

Apparently, the confusion still exists.

Sent by Law Mail

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