The sampling method was purposive, and participants were selected from among patients referring to Imam Reza Hospital according to the inclusion criteria. Subsequently, in order to randomly allocate participants into two groups (intervention and control), block randomization with a block size of four was used.
Accordingly, the letter A was assigned to the intervention group and the letter B to the control group. Then, six possible arrangements (AABB, BBAA, ABBA, BAAB, ABAB, BABA) were written on separate sheets of paper and placed into a container. One sheet was randomly selected, and the sequence written on it was recorded and then returned to the container. This procedure was repeated 19 times, and each time the selected sequence was recorded consecutively until the total sample size of 76 was achieved.
Numbers from 1 to 76 were assigned to each letter. Each letter was placed in a separate envelope, and the envelopes were labeled with numbers from 1 to 76. Each time a participant was enrolled, the envelopes were opened sequentially, and in this manner it was determined whether the participant was allocated to the intervention or the control group.