Blinding
taste, smell and packaging of the simulant, CRF
ADVERSE EVENTS, CRF, EMERGENCY, BLIND
This is a double-blind (patients and clinicians are blinded) and double-dummy study. A two-stage blind design is adopted. The first stage was the group corresponding to number of each case (such as group A, group B) and the second stage was the intervention corresponding to each group (experimental group or control group).Treatment assignments will not be revealed until the whole process is completed. Emergency letter will be opened by researchers when emergency (such as severe adverse events) or patient needs rescue and must know the treatment had received. Once the blind is broken, the patient with this number will be withdrawn from the trial handling as a dropout case and the researchers should record the reasons in the case report form (CRF). All emergency letters will be returned together with the CRF after the trial for blind review. When the blind codes are leaked or the opening rate of emergency letter exceeds 20%, the double-blind test will declare failure.To achieve blinding, the outer packaging of experimental and control drugs should be identical. Size, color, shape, taste, smell and packaging of the simulant are identical to that of the corresponding medicine by adding artificial pigment [