Figure 2.
Power of one- and two-stage designs for m = 100, T/m = 100, and values of μ = 0.275 for increasing values of correlation between adjacent markers. The bold line shows the maximum power of the optimal two-stage design. Optimal parameters (i and j) are shown below the horizontal axis. The dotted line shows the rule-of-thumb two-stage design (when i = 0.10 and j = 0.75). The dashed line gives the power of a one-stage design. The value of μ = 0.275 corresponds to a one-stage design with 60% power and independent markers.