There were three independent sets of subjects employed in these CD-phenotype analyses, in three phases. Phases 1 and 2 evaluated GWAS data from two different sets of subjects using two different, but similarly dense, microarrays: Phase 1 included our GWAS discovery dataset, consisting of 5,697 subjects. Phase 2 also incorporated information from the SAGE dataset, with GWAS data from 4,063 subjects. The assessments used for our study (SSADDA) and the SAGE study are sufficiently similar for most phenotype data to be combinable directly. Phase 3 included our replication dataset of 2,549 subjects who were (directly) genotyped for selected SNPs rather than for GWAS. Thus, analyses included up to 8,246 of our own subjects and 12,309 subjects overall. The overall analytic design is similar to that of our OD GWAS study.7 In our own subjects, we also analyzed the CIP trait (which is included in the SSADDA but not the SAGE assessment), limited to subjects with cocaine exposure.
