Topic: Unblinded Re-Estimation and the Promising Zone

Sensitivity to Interim Timing

Re-Estimation at Multiple Interim Looks

Re-Estimation for Binary Outcomes

Power Gain From Promising-Zone Expansion

Plug-In Conditional Power From Interim Estimates

Participant Burden and Cost Trade-Offs

Monte Carlo Precision for Re-Estimation Evaluation

No-Change Regions and No-Increase Rules

Lower and Upper Sample-Size Constraints

Mapping Conditional Power to a Revised Sample Size