OCRX (addendum)—I'm mostly curious how you got to 4% chance of futility. I have no feel for whether that is high, low or about right and could benefit from deeper understanding.
As I indicated in a prior post, the 4% figure is just a guess based on experience. However, what some readers may not know about futility analyses is just how futile they are. #msg-110052747 explains why this is so. Regards, Dew