Analyses in single cohorts were adjusted for sex, age and principal components for genetic ancestry. In total, meta-analysis included 3,440 subjects for the lifetime average CPD phenotype. Lambda inflation factors were between 0.996 and 1.018 for individual cohorts (table 1), and 1.019 for meta-analytic p values (see online supplementary figure 2 for a Q-Q plot of meta-analysis). Thirteen SNPs were associated with lifetime average CPD with meta-analytic p<10−5, however, no SNPs showed association with meta-analytic p<10−6 (table 2).
