Читать книгу Randomised Clinical Trials - David Machin - Страница 102

Although Protocol AHCC01 (1997) referred in the statistical methods to a 2 : 1 : 2 randomisation between placebo (P), tamoxifen 60/mg/day (TMX60) and TMX120 no reference to ‘randomisation in blocks’ was made. Nevertheless, the eventual trial publication of Chow, Tai, Tan, et al. (2002) stated:

Randomization was performed in balanced blocks of 5, stratified by center, and corresponding to P, TMX60, and TMX120 in the respective ratios of 2 : 1 : 2.

In contrast to randomised blocks, the PRESSURE (2000) trial used a minimisation method (see Chapter 5) with the four factors recruiting centre, skin condition, clinical specialty of the admitting hospital ward, and whether an acute or elective admission.

Just as we have suggested that it is desirable not to reveal the block size, the precise amount of randomness set in a minimisation method should not be revealed within the protocol itself, but should be documented in a separate memo by the statistical team.