Replies to post #138559 on Biotech Values

[p3analyze]

Clark - could you clarify
>>No. You have to put in .045 as the two sided alpha to get 705.<<

A strict OBF type boundary would have a nominal p-value of 0.043. You can't just apply the fixed sample size function by tinkering the alpha until you get the 705 event goal, right? Also, the smaller the interim spend, such as a haybittle-peto function, the less sample size inflation, the smaller the event goal.