Our genetic background analysis revealed significant levels of admixture among our AA study subjects. Given this, we explored the comparability of different methods to account for admixture in our analyses and found that three different methods – genomic control adjustment, logistic regression using a LAMP-generated covariate, and logistic regression using MDS-generated covariates – all produced very similar results within the AA population. Regression with either LAMP or MDS based covariates was effective for correcting artificially induced population structure when EA and AA samples were combined, but genomic control overcorrected for this, effectively removing any real association that was not associated with admixture levels.
