Martin's radon study

["Rad health" <healthrad@HOTMAIL.COM>]

Dr. Martin,



An interesting post.



A quick response:



1) When studies go through peer review for funding in the United States one 

of the things the reviewers look for before funding a study (especially an 

expensive study) is that the proposal documents that it has sufficient power 

to to address the study hypotheses.  If the study was funded, it went 

through that peer review.



2) The study was not funded to counter the findings of Dr. Cohen's studies.  

As Dr. Cohen has stated his study did not have the ability to examine the 

risk posed by residential radon exposure.



3) The statements you make about under reporting cigarettes is purely 

conjecture.  It may be a problem in Germany, but what evidence do you have 

to prove it is a problem for Iowa women.  Dr. Field offered examples to show 

that is not the case in his debate with Dr. Becker.

Dr. Field previously pointed out that to see a dose response as they did and 

have smoking responsible for that dose response, the cases would have to 

know their radon concentrations before hand and under report their smoking 

as their radon concentrations increase. This is not likely.





4) The Iowa study design was unique in its study design.



5) In looking back in the radsafe archives I note your earlier posts about 

your study.  It is of insightful that the study you lift up as the best 

study is an unpublished study you are a co-investigator for.  This is the 

same study that you were reporting the risks for prior to the completion of 

the study.  Shouldn't you decide a priori what your exposure categories are? 

  Aren't you introducing bias by telling your staff the introductory 

findings as you continue to conduct the study?



6) Unlike your description, the Iowa Study found a statistically significant 

dose response relationship with its categorical data for ALL subjects.



7)The possibility of selection bias was discussed in the paper and no 

differences were noted between people who took part in the study and those 

who did not.



If you think there are problems with the Iowa Study, why not present them in 

a scientific forum such as a letter-to-the-editor of the AJE?  Have you ever 

contacted Dr. Field directly about your concerns?  Isn't that a more 

scientific approach than posting on a public listserv?



When can we expect to see your study published in a peer reviewed journal?



Will your study be part of the European pooling?



Don



>From: precura.martin@T-ONLINE.DE (Dr. Karl Martin)

>Reply-To: precura.martin@T-ONLINE.DE (Dr. Karl Martin)

>To: "radsafe list" <radsafe@list.vanderbilt.edu>

>Subject: Iowa Radon  Lung Cancer Study

>Date: Sat, 26 Jan 2002 14:36:36 +0100

>

>The radon issue is extremely important as Ruth Weiner stated and it is 

>worth to be discussed. This is true especially when the Iowa Radon Study is 

>praised by EPA for its quality and as a landmark study by Don Smith and 

>therefore used to refute COHEN's and other results from radon studies not 

>in accordance with LNT.

>

>FIELD claims somewhat presumptuous that his study "...incorporated a unique 

>combination of study design and enhanced dosimetric techniques....". It is 

>not disputed that great efforts where made to measure smoking history and 

>radon exposure as precise as possible.

>

>Before discussing the influence of smoking and its control in the Iowa 

>Study a question regarding a possible selection bias has to be raised. The 

>study started with 1,974 female lung cancer cases and included in the end 

>283 cases ALIVE = 14,3% of all cases and 47% cases that met all 4 eligible 

>criteria.

>

>As BEIR VI stated, the lung cancer risk from smoking amounts to 10-20 and 

>that from indoor radon to 0,2-0,3 only. When case-control studies are 

>discussed, BEIR VI stated: " The detection of an excess risk of lung cancer 

>is potentially complicated also by an inability to control completely for 

>other lung-cancer risk faktors, paticularly cigarrette-smoking, which has 

>an RR (relative risk) of 10-20". Due to the overwhelming risk level for 

>lung cancer from smoking, the contribution of each single factor has to be 

>determined, when radon studies are conducted with mostly smokers among 

>cases and controls. A strong confounder as smoking can be fully controlled 

>in individual studies without error when correctly measured. FIELD measured 

>the influence from smoking with an elaborated questionnaire precisely. But 

>what he measured precisely was what cases and next of kind reported.

>

>Even with an underreporting of one cigarette per day, the relative error 

>with the estimation of the lung cancer risk from radon comprises 13%. 

>Underreporting of cigarettes smoked results always in a higher risk 

>estimate for radon. Lung cancer cases tend to minimise their possible own 

>contribution to their deplorable fate by reducing cigarettes smoked and 

>even deny their habit (CONRADY et al. 1999). This is common for all 

>life-style related diseases. As further examples see PEREZ-STABLE et al. 

>1990 and OFFER et al. 2000.

>

>FIELD could not establish a health hazard from radon when ALL cases (413) 

>where analysed (Table 4) because the odds ratios where not significant. 

>Only when a subgroup with only 283 cases ALIVE was used, a significant 

>result for one exposure category from four could be established. No 

>explanation has been given why less ALIVE cases (48) in the highest 

>exposure category deliver a significant result versus 67 cases for ALL with 

>a not significant result.

>

>What could be a possible explanation for this surprising change? The just 

>diagnosed ALIVE cases were interviewed. They were stressed by the evidence 

>and feeling of guilt for their possible contribution to their lung cancer 

>by smoking so they minimise their smoking habit and even deny it (smokers 

>became non-smokers). This results in a higher risk for lung cancer from 

>radon (OR 2,14). Possibly the next of kin reported more accurately about 

>the smoking history of the cases. This results in a smaller risk estimate 

>from radon (OR 1,79). Additionally it is impossible to report the true 

>amount of cigarrettes smoked over a period of 20 to 30 years because such a 

>strong confounder invalidates any risk estimate for lung cancer from the 

>weak cause of indoor radon when only one cigarrette per day is 

>underreported.

>

>When power is discussed, FIELD avoided any estimates. This is easily 

>understood when from own estimates for ALL cases (mobility included) a 

>power of 40,1% and for  ALIVE 50,8% resulted. For a "landmark study" 

>besides significant results with narrow confidence intervals a power >90% 

>is needed. There is no case-control study yet that fulfills these 

>statistical criteria for the quality of a study.

>

>Conclusion: Only studies with highly exposed validated non-smokers with a 

>wide range of exposure from 50 Bq/m³ to > 3.000 Bq/m³ can result in valid 

>risk estimates from indoor radon for lung cancer. Thuch studies are 

>possible in regions with high indoor radon exposure included in a cancer 

>registry (for example the Schneeberg region in Germany, CONRADY et al. 

>1999). The pooling of biased data is not the solution. When biased data, 

>especially due to data from smoking history are used, the result would be 

>biased, too even when some thousend of cases are added up in such a study.

>

>References:

>

>Conrady J, Martin K, Poffijn A, Tirmarche M, Lembcke J, Do Minh Thai, 

>Martin H: High residential radon health effects in Saxony (Schneeberg 

>Study). Contract N° FI4P-CT95-0027, European Commission, DG XII, Nuclear 

>Fission Safety Programme. PreCura Institute for Preventive Medicine, 

>Schneeberg, August 1999 (www.precura.de)

>

>Perez-Stable EJ, Marin BV, Marin G, Brody DJ, Bennowitz NL: Apparent 

>underreporting of cigarette consumption among Mexican American smokers. Am 

>J Public Health 80 (1990), pp 1057-1061

>

>Offer D, Kaiz M, Kenneth I, Bennet H, Bennet E: The altering of reported 

>experiences. J Am Acd Child Adolesc Psychiatry 39(6), 2000, pp 735-742

>





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