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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




Details of statistical problem in JACC article

Specifically, what the authors did in the article was compare a control group and a chest pain group. They then subdivided the chest pain group into patients with low myocardial perfusion reserve, and those without low myocardial perfusion reserve. This resulted in three groups of patients.  1) Chest pain patients with low myocardial perfusion reserve. 2) Chest pain patients with normal or high myocardial perfusion reserve.  3) An undivided control group.

The authors then inappropriately statistically compared the three groups in regard to myocardial perfusion reserve, which is the same value that was used as the basis for selectively subdividing the chest pain group.  Naturally, the chest pain group with the low myocardial perfusion reserve would have a statistically different value as their mean myocardial perfusion reserve compared to the undivided control group. The authors then went and compared the groups for three other values. This included maximal myocardial blood flow and resting myocardial perfusion which are all related to myocardial perfusion reserve. This was without statistical validity.  

For a complete review of this, see what is included and called “Analysis of Broad Statistical Methods and Conclusion” which critiques the article by Geltman et al. (further details)

1. Increased Myocardial Perfusion at Rest and Diminished Perfusion Reserve in Patients With Angiographic Normal Coronary Arteries.  Geltman EM, et al. JACC 1990; 16:586-95.