“Increase sample size until statistical significance is reached” is not a valid adaptive trial design; but it’s fixable.
TLDR: Begin with N of 10, increase by 10 until p __ 0.05 or max N reached. This design has inflated type-I error. Lower p-value threshold needed to ensure specified type-I error rate. The number of interim analyses and max N affect the type-I error rate. Threshold can be identified using simulation. A recent ... [Read more...]