Table 2.

Operating characteristics for the six scenarios, averaged over simulated trials, for three blocks with patients per block. Each column is a different trial design: AC, FC (0.3,0.3),..., FC (0.5,0.7) are all enrichment trials. These designs do not restrict entry in the first block. ‘A-C’ uses adaptive cutpoints in the second and third blocks with candidate values . ‘F-C(,)’ uses fixed cutpoints with value in block and in block . ‘Non-A’ is a standard unenriched design. ‘Sensitivity’ and ‘Specificity’ are given for detecting the population which benefits. ‘Effect size’ is the true effect size for the designated population. ‘Bias’ is the amount by which each procedure over-estimates that effect size. ‘root-MSE’ is the root-mean-square error of the effect size estimate for the designated population. All operating characteristics, other than power and accrual time, are averaged only over successful trials

		AC	Non-A	FC(0.3,0.3)	FC(0.5,0.5)	FC(0.7,0.7)	FC(0.5,0.7)
1	Power	0.82	0.03	0.64	0.78	0.88	0.82
	Sensitivity	0.92	1	0.93	0.92	0.9	0.91
	Specificity	0.92	0	0.91	0.92	0.93	0.92
	Accrual time	542	300	468	526	604	558
	Effect size	0.22	0	0.22	0.22	0.23	0.22
	Bias	0.03	0.14	0.04	0.02	0.01	0.02
	Root-MSE	0.06	0.14	0.06	0.06	0.05	0.05
2	Power	0.38	0.38	0.39	0.39	0.38	0.37
	Sensitivity	0.87	1	0.91	0.89	0.85	0.86
	Specificity	X	X	X	X	X	X
	Accrual time	426	300	345	404	483	441
	Effect size	0.09	0.09	0.09	0.09	0.09	0.09
	Bias	0.05	0.06	0.05	0.05	0.04	0.05
	Root-MSE	0.06	0.07	0.06	0.06	0.05	0.06
3	Power	0.87	0.6	0.82	0.88	0.91	0.88
	Sensitivity	0.88	1	0.9	0.88	0.87	0.88
	Specificity	0.76	0	0.75	0.77	0.78	0.78
	Accrual time	414	300	358	402	468	430
	Effect size	0.19	0.12	0.19	0.19	0.19	0.19
	Bias	0.02	0.04	0.03	0.02	0.02	0.02
	Root-MSE	0.05	0.05	0.06	0.05	0.05	0.05
4	Power	0.29	0.18	0.2	0.29	0.32	0.34
	Sensitivity	1	1	0.99	0.99	0.99	0.99
	Specificity	0.31	0	0.2	0.31	0.34	0.34
	Accrual time	512	300	393	485	521	527
	Effect size	0.07	0.05	0.06	0.07	0.07	0.07
	Bias	0.07	0.07	0.08	0.07	0.06	0.06
	Root-MSE	0.08	0.07	0.09	0.08	0.07	0.07
5	Power	0.48	0.32	0.38	0.46	0.53	0.51
	Sensitivity	0.99	1	0.99	0.99	0.98	0.99
	Specificity	0.37	0	0.29	0.37	0.38	0.39
	Accrual time	468	300	378	450	510	491
	Effect size	0.11	0.07	0.1	0.11	0.11	0.11
	Bias	0.05	0.06	0.06	0.05	0.04	0.05
	Root-MSE	0.06	0.06	0.07	0.06	0.06	0.06
6	Power	0.53	0.5	0.51	0.52	0.55	0.53
	Sensitivity	0.81	1	0.87	0.83	0.76	0.81
	Specificity	X	X	X	X	X	X
	Accrual time	423	300	347	408	501	448
	Effect size	0.1	0.1	0.1	0.1	0.11	0.1
	Bias	0.05	0.04	0.06	0.05	0.04	0.05
	Root-MSE	0.06	0.05	0.06	0.06	0.05	0.06