Are these data real? Statistical methods for the detection of data fabrication in clinical trials

This criticizm of the Al-Marzouki et al analysis stems from a
misunderstanding of the definition for a single-blind study.

Mr. Williams "standard definitions" are taken from a textbook of
Pharmacology which gives the definitions for Pharmacological studies.
These definitions are correct for
an open (unblinded) study (- the experimenters and the subjects are aware
of the conditions), and for a double-blind study (- both the experimenters
and the subjects are unaware of the conditions). However, the definition
for a single-blind study is not the full scientific definition.

A single blind study is one in which EITHER the experimenter OR the
subjects are unaware of the conditions!

In Pharmacological single blind trials (such as clinical trials of
new drugs) it is always the subjects who are "blind", since some recieve a
placebo. However, in diet studies (such as the one Al-Marzouki et al
analysed), the subjects always know what they are eating, so in this case
a single blind study means that the experimenters doing the various
measurements do not know to which group (intevention diet or control) the
person they are checking belongs. Thus, no bias of the data should have
been expected.

In any case, even if the trial was known to be unblinded, this would
still not explain the two other statistical tests. It is the combination
of the differences in means, variances, and digit preference which
strengthens the conclusion that data fabrication took place in the diet
trial.

Competing interests:
None declared