Table 4.

Characteristics of Optimal (for ETSL) Design Assuming Misspecification of Accrual

	Scenario 1*		Scenario 2*		Scenario 3*
Actual/Anticipated Accrual	α	1-β	α	1 - β	α	1 - β
0.25	.1	.512	.070	.687	.109	.924
0.50	.1	.711	.082	.800	.106	.918
1.00	.1	.900	.100	.900	.100	.900
1.50	.1	.963	.114	.934	.092	.863
2.00	.1	.986	.115	.970	.079	.779

* Scenario 1 – Analysis at t₁ and MTSL ; Scenario 2 – Analysis at t₁ and one year after t₁ or one year after accruing n patients, whichever is later; Scenario 3 – Analysis after accrual of n₁ patients and one year after accruing n patients.