Data were analyzed from January 2, 2013, to November 9, 2015. Association analyses were performed using a count of DSM-IV CAD criteria (0–7) as the outcome variable and the imputed minor allele dosage (adjusted for sex, age, and the first 3 ancestry principal components) as a predictor variable. This ordinal trait model has greater power to detect genetic associations than a univariate model based on disease status because of greater information content and improved specificity of the dependence measure. Association tests were performed using linear association models embedded in generalized estimating equations to correct for correlations among related individuals.32 Analyses were performed separately within each data set and population group, and the results were combined by meta-analysis using the inverse variance method implemented in the program METAL.33 Genomic inflation factors (λ) were calculated within each subpopulation, and P values were corrected accordingly. We performed a second correction for the λ factor calculated after the meta-analysis.
