Table 3.

Power of meta-analysis of GWAS for two studies using PCA correction, single GC correction (1 GC), and double GC correction (2 GC) at significance levels of 10^–5, 10^–6, and 10^–7

Study 1			Study 2			10–5			10–6			10–7
R	Case	Control	R	Case	Control	PCA	1 GC	2 GC	PCA	1 GC	2 GC	PCA	1 GC	2 GC
1.2	1000	1000	1.2	1000	1000	0.1901	0.0402	0.0425	0.0908	0.0113	0.0124	0.0384	0.0041	0.0045
	1000	1000	1.3	1000	1000	0.4449	0.1207	0.1194	0.2797	0.0511	0.0502	0.1637	0.0199	0.0196
	1500	1500	1.4	500	500	0.4232	0.1368	0.1450	0.2631	0.0604	0.0645	0.1437	0.0238	0.0253
	1500	750	1.5	750	1500	0.8332	0.4306	0.4368	0.7221	0.2724	0.2787	0.5959	0.1549	0.1602
1.3	1500	1500	1.3	500	500	0.7029	0.2412	0.2375	0.5487	0.1228	0.1205	0.3934	0.0552	0.0535
	1000	1000	1.4	1000	1000	0.8768	0.4703	0.4806	0.7738	0.3003	0.3085	0.6386	0.1709	0.1800
	1000	1000	1.5	1000	1000	0.9425	0.6377	0.6403	0.8835	0.4683	0.4702	0.8060	0.3128	0.3152
1.4	750	1500	1.4	1500	750	0.9551	0.6532	0.6570	0.9046	0.4740	0.4782	0.8251	0.3190	0.3215
	1500	1500	1.5	500	500	0.9700	0.7008	0.6986	0.9302	0.5442	0.5400	0.8733	0.3819	0.3773
1.5	1500	750	1.5	750	1500	0.9952	0.8942	0.8930	0.9842	0.8044	0.8028	0.9686	0.6844	0.6824

Boldface values denote the highest power among meta-analyses using the three methods (PCA, 1 GC, and 2 GC).