In this study, the block randomization method will be used to ensure that exactly the same number of participants enter the groups in a consecutive but equal time interval.
At first, based on the sample size, we evaluate all possible states (permutations) of block formation, so that based on the sample size (48 people), 8 blocks of six will be produced. In each block, 6 of the three groups A, B, C (group A: intake of anti-inflammatory diet, group B: intake of barberry, group C: intake of barberry and anti-inflammatory diet) will be included twice. The blocks are produced by the statistics consultant and the envelope will be used to hide the blocks.
We will assign people to three groups according to the group names in the blocks. Each of the blocks is numbered and will be used, that is, if block number 1 (for example, ABCABC) is selected by lottery, the first patient will receive treatment A, the second patient will receive treatment B, the third patient will receive treatment C, the fourth patient will receive treatment A, and the fifth patient will receive treatment B. The sixth patient will take C. For the 7th patient and onward, I consider one of the previously specified blocks by random drawing again, and for assigning people to groups, we consider the sequence of this block as the same as the first block.
One of the potential problems in the blocking method is the disclosure of the last allocation in each block. This problem occurs when the study uses the blocking method with fixed blocks, which is not used in this study. Rather, the blocks are randomly selected.
Software and sites also generate this block random sequence, such as:
www.randomization.com
www.sealedenvelope.com