Table 4 Score results \(S(\lambda )\) for the recalculation rules in the APSAC simulation. The values in the table correspond to Fig. 3. The first stage sample size is set to \(n_{1}=90\), the maximum sample size is set to \(n_{max}=270\) with global one-sided significance level \(\alpha = 0.025\), efficacy stopping boundaries were chosen according to Pocock [15] and binding futility stopping bound represented by \(\alpha _{0}=0.5\). OCP: Observed conditional power approach; restrOCP: Restricted observed conditional power approach; Promising: Promising zone approach; OptFunc: Optimization function approach; classicGS: group sequential approach

From: Extension of a conditional performance score for sample size recalculation rules to the setting of binary endpoints