First, we would like to clarify that the sample size of our RCT was calculated correctly, based on the relevant data available from reported studies before our RCT began. An incidence of 68% and 20% was reported for RYGB (2) and SG (3), respectively. Therefore, the absolute difference in the occurrence of hypoglycemia between the two surgical procedures was ∼50%. However, we considered a more conservative difference of 30% and calculated that, with two-tailed P < 0.05 and a test power of 0.90, 50 subjects in each group would have been sufficient to meet the criteria for superiority compared with SG treatment. Considering an attrition rate of 20%, the patients enrolled were 120 overall, with 60 in each group.
- Biochemistry (medical)
- Clinical Biochemistry
- Endocrinology, Diabetes and Metabolism