Table 2: Sample size calculations for 1-sided and , for different treatment effects in the two subgroups. RRtrt is the response rate in the treatment group, RRcontrol is the response rate in the control group, and RRRtrt:control is the ratio of response rates in the treatment versus control groups (i.e., treatment effect).

CaseM+ subgroupM− subgroup
Treatment effect, RRRtrt:controlRRtrt/RRcontrolTreatment effect, RRRtrt:controlRRtrt/RRcontrol

I (no interaction)20.4/0.26520.4/0.265
II (interaction)20.4/0.2650.5 (i.e., reverse benefit)0.1/0.2161