Genetic association tests will be performed for both qualitative and quantitative COPD-related phenotypes. Separate association analysis will be performed in the GOLD Stage 1 subjects and GOLD-U subjects to see if these subsets have significantly different distributions of disease-associated alleles and/or haplotypes compared to those seen in other GOLD Stage subjects. Power to detect significant associations with COPD for specific candidate gene SNPs was determined for the approximate case-control samples of African Americans (1500 cases/1500 controls) and non-Hispanic whites (3000 cases/3000 controls) after adjusting for multiple comparisons. Power to detect a significant association was 99% for OR ≥1.5 with allele frequency >0.1 (NHW), and for OR ≥1.75 with allele frequency ≥0.1 (AA).
