We also performed meta-analysis of ARIC and COPDGene AA study subjects for the pack-years of smoking phenotype which improved the significance (p = 6.126e-05; -log10(6.126e-05)~4.21) compared to the p-values obtained from COPDgene study alone (p = 0.00017; -log10(0.00017)~3.77). We checked for association between polymorphic CNVs with the average cigarette smoked per day among AAs in the ARIC study. The average cigarette smoked per day among AAs in ARIC was 19.2, and was slightly lower than cigarettes per day reported by AA subjects in COPDGene study 21.2. Although the reported average cigarettes smoked per day was not significantly associated with the polymorphic CNV on chr. 3p26.1 (p = 0.221) in the ARIC study (see S2 Table), a meta-analysis combining AA subjects from ARIC and COPDGene study improved the significance (p = 0.0001577; -log10(0.0001577)~3.80) compared to the p-values obtained from COPDgene study alone (p = 0.000254, -log10(p) = 3.59).
