Randomisation and masking
REMISSION
All participants were randomly assigned to one of two groups: the tofacitinib discontinuation group and the MTX discontinuation group at baseline. Randomisation was done on a 1:1 basis, and randomisation with assignment concealment is done by the central coordinator by use of a computer-generated simple randomisation method. After randomisation, either a dosage of tofacitinib 5 mg two times a day or 5 mg per day was administered in addition to MTX in both groups. The randomisation was performed at baseline but not at week 52 to facilitate the study procedures after week 52. The results of the randomisation remained hidden from both patients and the investigators until week 52. At week 52, either tofacitinib or MTX was discontinued according to the assignments if a patient achieved clinical remission as defined by CDAI. After discontinuation of the drug at week 52, patients did not take placebo pills, resulting in no blinding.