Medical student doing his first research here. This is a randomized controlled trial. Basically the study compares the effectiveness of skin glue over skin sutures. Since the length of each scar will be different in different patients, and I have the closure time as the primary outcome, how do I go about this?
2) Alternatively, can I calculate a sample size expecting a 50% difference in the primary outcomes? If so, how? Any link to a calculator for the same?