Table 3.

Operating characteristics for the three redesign scenarios of Bokemeyer and others (2009), averaged over simulated trials, for two blocks with patients per block. Each column is a different trial design: AC, FC (0.3), FC (0.5), FC (0.7) are all enrichment trials. These designs do not restrict entry in the first block. ‘A-C’ uses an adaptive cutpoint in the second block with candidate values , ‘F-C()’ uses a fixed cutpoint with value . ‘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)	FC (0.5)	FC (0.7)
1	Power	0.68	0.23	0.62	0.69	0.73
	Sensitivity	0.99	1	0.99	0.99	0.99
	Specificity	0.92	0	0.92	0.93	0.89
	Accrual time	454	336	423	452	478
	Effect size	0.21	0.06	0.21	0.21	0.2
	Bias	0.04	0.07	0.05	0.04	0.04
	Root-MSE	0.06	0.08	0.07	0.06	0.06
2	Power	0.81	0.68	0.79	0.84	0.86
	Sensitivity	0.98	1	0.98	0.98	0.98
	Specificity	0.56	0	0.51	0.58	0.58
	Accrual time	412	336	376	406	442
	Effect size	0.18	0.13	0.18	0.18	0.18
	Bias	0.04	0.03	0.05	0.04	0.03
	Root-MSE	0.06	0.05	0.06	0.06	0.06
3	Power	0.38	0.03	0.22	0.37	0.45
	Sensitivity	1	1	1	1	1
	Specificity	0.76	0	0.83	0.8	0.74
	Accrual time	488	336	452	488	488
	Effect size	0.15	0.01	0.17	0.16	0.14
	Bias	0.08	0.12	0.09	0.07	0.08
	Root-MSE	0.09	0.12	0.1	0.09	0.09