Random allocation in this study is done by simple randomization method. Randomization based on a single sequence of random allocations is called simple randomization. The randomization unit in this study is individual and the random number table tool is used. Random number table is a set of numbers that are generated without a specific pattern or order and in a completely random form and become a table. To use the table of random numbers, we first preset the table to read the numbers (for example, up, down, left Or right) and then we consider numbers for the three groups in question. Consider the numbers 00-29 for intervention A, the numbers 30-59 for intervention B, and the numbers of 60-89 for group C. The researcher then touches one of the numbers and moves in one of the predetermined directions and records the numbers and assigns them to different groups, thus making a random sequence.
Random allocation concealment refers to the method used to execute random sequences on study participants, in a way that prior to individual allocation, group allocated is not specified. In this study, in order to hide the random allocation, the method of opaque envelopes sealed with a random sequence is used. In this method, after making a random sequence based on the sample size of the research, a number of envelopes with aluminum wrapping (in order not to clarify the contents of the envelopes) are prepared and each of the random sequences created is recorded on a card and the card is sealed. Letters are placed in order. In order to preserve the random sequence, the numbering of the envelopes on the outer surface is done in the same way. Finally, the lids of the letter envelopes are glued and placed inside a box, respectively. At the beginning of the registration of participants, based on the order of entry of eligible participants to study, one of the envelopes of the letter is opened in order and the assigned group of the participant is revealed.