Table 3.

Power calculations in combined sample related to the range of allelic summary ORs detected by the meta-analyses in AlzGene

Odds ratio	Minor allele frequency in general population
	0.05	0.10	0.20	0.50
1.10	0.08	0.11	0.16	0.22
1.15	0.13	0.19	0.30	0.39
1.25	0.26	0.43	0.63	0.74
1.50	0.72	0.92	0.99	0.99
1.75	0.96	1	1	1

Power after combining all four family datasets (4,180 samples from 1,344 pedigrees) using an additive disease model. An OR of 1.25 (bold) is approximately equivalent to the average OR found in the 41 significant meta-analyses in December 1, 2007, data freeze when excluding likely APOE-related effects (see [1] for details). Assumed disease prevalence 10%, α=0.05