The use of unadjusted genotype counts is not appropriate for some samples (e.g. SGENE-plus because of relatedness among the Icelandic Groups and MGS because of extensive structure in the dataset), therefore, we used the inverse variance method of meta-analysis. For each study, variance was calculated based on the 2×2 contingency table counts, or the 95% confidence intervals values provided by SGENE plus, the MGS, and the unpublished Swedish GWAS. Heterogeneity between studies was assessed using Cochran’s Q statistic.
