. Author manuscript; available in PMC: 2019 Feb 20.

Published in final edited form as: Stat Med. 2017 Nov 21;37(4):507–518. doi: 10.1002/sim.7561

Table 2.

Trials for the treatment of advanced colorectal cancer. The surrogate endpoint indicates cancer progression (or not) between 3 and 6 months. The true endpoint indicates overall mortality (or not) by 12 years.²⁷ The estimated treatment effects are differences in fractions that account for censoring.¹⁵

Trial	Estimated effect of treatment on the surrogate endpoint	Estimated effect of treatment on the true endpoint	Average sample size per arm	Estimated sampling variance of the effect of treatment on the true endpoint
i	x_i	y_i	n_i	w_i
1	0.0101776	−0.00300867	434	0.00223822
2	0.0175788	0.0474206	272	0.0040373
3	0.0600888	0.137713	184	0.00516377
4	0.0609015	0.0000155292	490	0.00228519
5	0.0925625	0.0398926	488	0.00202247
6	0.1018	0.079676	310	0.00320678
7	0.169392	0.15072	422	0.00229129
8	0.178005	0.144626	136	0.00701305
9	0.199408	0.170422	206	0.00510997
10	0.339943	0.200604	148	0.00219454