0 05 summary data including odds ratios and variances were obtained from the charge cohorts for heart and aging research in genomic epidemiology 25 and eadi1 studies such that all data i e our stage 1 amp 2 eadi1 adni tgen and charge were combined in an inverse variance weighted fixed effects meta analysis total sample of up to 11607 cases and 31871 controls cochran 39 s q test was performed and i 2 calculated to assess heterogeneity although the same direction of effect was observed in all studies analyzed for the cr1 snp rs3818361 there was some evidence of heterogeneity cochran 39 s q test p 0 02 i 2 65 a random effects meta analysis of this snp was also performed for comparison see table s15 we also tested the gws snps for relationships with age at onset aao to this end age at onset in years was employed as the dependent variable in a linear regression analysis and an additive model was assumed aao data was available for 2 856 ad cases covariates were included in the logistic regression analysis to allow for geographical region and chip i e to distinguish between 1 cases from the british isles 2 cases from germany 3 cases from the us typed on the 610 chip 4 cases from the us typed on the 300 chip results are shown in table s12 in addition we stratified our sample based on presence absence of at least 1 apoe u03b54 allele we had apoe genotype data for 6045 individuals our u03b54 positive sample consisted of 2 203 ad cases and 632 controls our u03b54 negative sample consisted of 1 446 cases and 1.