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Med Hypotheses. 1999 Jul;53(1):69-70.

Edta chelation therapy: an ethical problem.

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Aarhus Medical Test Center, Inc., Aabyhoej, Denmark.


The randomized, double-blind study is generally regarded as the ideal standard of clinical drug trials, but uncritical blinding in clinical studies should be questioned (1,2). Most often, the method of randomization is not sufficiently described. There are examples of researchers having used opaque envelopes or opened several envelopes or X-rayed the envelopes. Violation of the randomization is unfortunately common (3). New guidelines for structured reporting of clinical trials with focus on the randomization method have been worked out (4). However, other methods of violation of the randomization have not been covered in the new guidelines. In a claimed double-blind multi-center study, isotonic Na2 ethylenediaminetetraacetic acid (edta) solution as verum and isotonic saline as placebo was used without any problem with the blinding. In the multi-center study, only nine incidents of burning at the infusion site were registered out of a total of more than 1000 Na2edta infusions (5). In our study, a total of 10 persons were given exactly the same kind of infusions and nine out of 10 receiving Na2edta infusions reacted with burning at the infusion site, thus proving it impossible to use Na2edta versus saline and maintain the blinding in a study of double-blind design. The difference in painful reactions between the Na2edta group and the saline group at the infusion site is statistically significant (P<0.001).

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