In each of the two intervention groups, the participants are divided into randomized blocks based on the randomization process after confirming that they have the conditions to enter the project. Randomization in this way has been done with the help of 4 random blocks. Each of the houses is A or B, and when the patients go to the hospital, depending on the prepared envelopes, where the patient's number and the type of intervention A or B are marked on each envelope and the type of intervention A or B is marked inside the envelope, from the box containing product A Or it is given from the box containing product B.
In this study, 6 types of blocks for each block of 4 can be expected, with two placebo and two intervention volunteers in each group. Each block model is marked with a number from one to six, and for each block, a random number is taken from 1 to 6 with the help of Microsoft Excel, which determines the sequence of receiving cream and placebo for each person, and the total sequence . And the order of 20 blocks of this study is determined.
Initially, patients are included in the process of research and are added to the plan if they wish. For more familiarity and assurance, an informed consent form is given to them. After entering the plan and seeing a bruise at the place of filler injection, in the first visit, they will be given an envelope containing the representative number of each person based on the appointment and the number that will be assigned to them. There is a sheet in each of these envelopes, some of which are sheet A and others are sheet B. Depending on which sheet the patient's envelope contains, a cream from box A or a cream from box B will be given from the two boxes available to the nurse of the plan.
A double-blind study means that all creams and boxes A or B are blinded for the research doctors of the plan, the executive director, the associate nurse, the patients, and all the hospital staff. Also, the formulation company delivers the intervention cream and placebo in the form of two separate boxes, and the labeling of which cream A contains intervention cream (demo) or placebo and B is done only by and with the knowledge of the plan's statistical consultant. And only he is aware of the grouping, but he does not participate or interfere in the process of implementing the plan. The method of randomization is based on the method that was explained.
All the creams with white tube and no explanation except that they are A or B. And in the process of formulating both, all facilities are used by the patient to match the color, smell, consistency, appearance and other tangible characteristics so that the type of cream available in each group A and B is not predictable.