. Author manuscript; available in PMC: 2013 Sep 12.

Published in final edited form as: Ann Stat. 2011;39(6):3234–3261. doi: 10.1214/11-AOS937

Table 2.

Simulation results to evaluate the operating characteristics of a study to evaluate the predictive accuracy of DCP using a fixed-sample design and group sequential designs with two, three or four stopping times. Presented are the probability of rejecting the null hypothesis and expected sample size under the null and alternative hypotheses. 10000 simulations were performed for each scenario.

Stopping Times	NPV (0.6) = 0.90		NPV (0.6) = 0.95		NPV (0.6) = 0.90		NPV (0.6) = 0.95
	PPV (0.9) = 0.80		PPV (0.9) = 0.80		PPV (0.9) = 0.90		PPV (0.9) = 0.90
	P(reject)	E(n_D)	P(reject)	E (n_D)	P(reject) 0.026	E(n_D)	P(reject)	E(n_D)
J = 1	0.003	702	0.03	702	0.026	702	0.917	702
J = 2	0.004	432	0.026	492.4	0.024	489.5	0.924	624.5
J = 3	0.004	367.4	0.022	431.3	0.023	433	0.917	580.1
J = 4	0.002	340	0.023	410.7	0.024	417.2	0.911	571.1