Additional file 3 of Choice of futility boundaries for group sequential designs with two endpoints

Probability of stopping for futility and overall power for Approach 2. Plot of probability of stopping for futility (left figure) and overall power (right figure) for Approach 2 using the futility β γ-boundaries α f CE = 0.65 $ \alpha_{f}^{CE}=0.65$ and α f MC = 0.37 $ \alpha_{f}^{MC}=0.37$ for composite endpoint and main component, respectively. (JPG 238 kb)