Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled study

The BMJ asks authors of reports of randomised trials to follow the
recommendations of the CONSORT statement[1]. With regard to randomisation,
authors are asked to indicate the method used to generate the allocation
schedule and the method of allocation concealment. The paper by
Schellenberg and colleagues [2] includes just one sentence relating to the
randomisation: "Randomisation was provided centrally in blocks of four."
It is not clear from this statement how the random sequence was generated,
nor whether the allocation was concealed. Did physicians have to telephone
a central office to enrol patients in the trial, or was the centrally
provided sequence provided on paper, for example?
In addition, 91 patients were randomised to the active arm and 87 to
placebo. These numbers are impossible given randomisation in blocks of
four. Perhaps some restricted randomisation was used, such as
stratification. If so, this should have been mentioned.

1 Begg C, Cho M, Eastwood S, et al. Improving the quality of
reporting of randomized controlled trials. The CONSORT statement. JAMA
1996;276:637-9.

2 Schellenberg R for the study group. Treatment for the premenstrual
syndrome with agnus castus fruit extract: prospective, randomised, placebo
controlled study. BMJ 2001;322:134-7.