93
Case Study:
Sponsor’s Futility Boundary
Sponsor opted for futility boundary based on P= 0.8
•Power – ASN tradeoff
–Worst case loss of power .0071
•(from 0.738 to 0.731 when difference in mortality is -0.0566)
–
–10.2% gain in average efficiency under null
•(ASN from 1099 to 987 when difference in mortality is 0.00)