Table A2.

Design specifications for different values of λ for Design 2 and an interim analysis after half the patients have been observed. c ₁ is the upper stopping boundary at stage 1, c ₂ the final stage critial value, and N the total sample size. The lower bound at stage 1 is fixed at zero for all λ

λ	0.05	0.1	0.15	0.2	0.25	0.3	0.35	0.4	0.45	0.5
c 1	3.018	3.031	3.037	3.039	3.039	3.037	3.034	3.029	3.023	3.016
c 2	2.134	2.143	2.147	2.149	2.149	2.148	2.145	2.142	2.138	2.133
N	719	401	298	251	224	207	196	188	183	181
λ	0.55	0.6	0.65	0.7	0.75	0.8	0.85	0.9	0.95
c 1	3.008	2.999	2.989	2.977	2.964	2.948	2.930	2.907	2.875
c 2	2.127	2.121	2.114	2.105	2.096	2.085	2.072	2.055	2.033
N	181	184	192	205	229	269	342	491	943