Table 3.

Operating characteristics for Scenario B when 4 drugs are assessed and two are effective: Power 1 (probability that at least 1 of the 2 drugs correctly identified as effective) and Power 2 (probability that both drugs correctly identified as effective) by proportion of shared controls under COPPS (estimated from simulation) relative to 4 independently run trials with no shared controls (theoretically derived probabilities).

COPPS			Four independent trials No Shared Controls
Proportion of shared controls	Power 1	Power 2	Power 1	Power 2
3% (2/60)	0.993	0.839	0.993	0.836
50% (30/60)	0.986	0.849
96.6% (58/60)	0.974	0.858