Sample size and randomization
The study used G power software version 3.1.9.4 and was based on previous research that found a relapse rate of 23.5% for patients receiving immunosuppressive drugs compared with 59.1% for control patients with GD. With an alpha error of 0.05, power of 95%, and response rate of 30%, the minimum required sample size for each group was determined to be 68. A computer program generated a list and randomly allocated patients into three groups matched for age, sex, and TRAb. The first group (