Sample size
For the purpose of comparing independent results, we decided to use power of 0.85 and a significance level of 0.05, to detect a significant difference. The difference in the percentage change in FF after 4 weeks of treatment in the canagliflozin group compared with that in control group was assumed to be 60% of the standard deviation. Based on these calculations, we determined that at least 50 individuals are necessary for each group. Taking into account potential discontinuation and withdrawal, we set the target number for the canagliflozin group to 55, with 55 control patients, and thus, 110 patients were planned to be included in total. Additionally, we took into account the actual number of patients who met the registration criteria at each facility.