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Specific guide to this web site for:

 1.  Medical School
      in Statistics

 2.  Medical Students

 3.  Science media writers

 4.  High School & College
     Statistic Teachers


1. Harvard led MI study

2. JACC study 

   (J. of Amer. Coll.

3. NEJM cath study

4. Amer. J. of Cardio.
    review of literature


Oat bran study

Pregnancy & Alcohol

Are Geminis really
9. Columbia 'Miracle' Study  

Additional Topics:


Limitations of Meta-Analyses

Large Randomized Clinical Trials

Tale of Two Large

Advocate meta-analyses

Network meta-analyses





Eric Roehm, M.D. 

December 29, 1994 

Robert Roberts, M.D. 
Chief of Cardiology 
Baylor College of Medicine 
6535 Fannin, Mail Station F-905 
Houston, TX 77030 

Dear Dr. Roberts, 

Your group recently published a study on the effect of low dose aspirin on the inhibition of platelet aggregation during the first two hours following acute aspirin ingestion. Your study documents that low dose aspirin inhibits arachidonic acid precipitated platelet aggregation completely and early following aspirin ingestion. 

The question remains whether this inhibition of arachidonic acid precipitated platelet aggregation with low dose aspirin is representative of the results obtainable when other agents are used to induce platelet aggregation. My understanding of the position taken by you in a recent talk given in Austin is that the literature suggests this finding holds true regardless of which platelet aggregation agent is employed. The study by Kuster et al is thought to be an outlier from the other experimental data published, possibly on the basis of problems with his platelet aggregometer technique. 

I submit this challenge and alternative hypothesis. Review the accompanying materials for the next five minutes. In my opinion, this will show that the prior experimental literature, including your study and the Kuster et al study (among others), is consistent with one another in general. 

Low dose, acute ingestion of aspirin with arachidonic acid precipitated platelet aggregation fully inhibits platelet aggregation. Collagen precipitated aggregation is not inhibited by single doses of low dose aspirin. 

Unfortunately, the literature in your review inadvertently misquoted the prior literature. This results in the erroneous impression that the literature in general indicates that the inhibition of platelet aggregation is independent of which aggregatory agent is employed except for the Kuster study, which is an outlier. A closer review of the data from these studies shows that the data generated by the Kuster study, Mehta study, Paccioretti study, and your study is consistent and that the data from no study is appropriately discarded. 

Enclosed is the information for your direct review. 

link to printed literature that accompanied Robert Robert's letter

Sincerely yours, 

Eric F. Roehm, M.D. 


cc: Salim Dabaghi, M.D. Andrew Schafer, M.D. Neal Kleiman, M.D.