Concealment mechanism
RECRUITMENT
Sealed opaque envelopes, indicating the allocation of each participant in accordance with the recruitment number, will be prepared in advance. The researcher who will enroll the participants will be given envelopes displaying the allocation at the time of recruitment. Then, a special participant recruitment number will be assigned to each participant for those who meet inclusion and exclusion criteria and give informed consent in chronological order. The sealed envelope containing the allocation for the given recruitment number is opened, and the corresponding participant will be assigned either into the intervention or control group.