Table 3.

Evaluable sample size estimates

PTB rate in Placebo Arm	PTB rate in ASA	% Red.	Sample size per group	PTB rate in ASA	% Red.	Sample size per group	PTB rate in ASA	% Red.	Sample size per group
Power = 80% (α = 0.05; β = 0.2)
8%	4.8%	40%	918	6.0%	25%	2554	6.40%	20%	4096
10%	6.0%	40%	721	7.5%	25%	2005	8.00%	20%	3213
12%	7.2%	40%	591	9.0%	25%	1638	9.60%	20%	2625
14%	8.4%	40%	497	10.0%	25%	1377	11.20%	20%	2204
Power = 90% (α = 0.05; β = 0.1)
8%	4.8%	40%	1228	6.0%	25%	3419	6.40%	20%	5483
10%	6.0%	40%	965	7.5%	25%	2683	8.00%	20%	4301
12%	7.2%	40%	790	9.0%	25%	2193	9.60%	20%	3513
14%	8.4%	40%	665	10.5%	25%	1842	11.20%	20%	2950