Quantile-quantile (Q-Q) plots did not show large deviations between observed and expected P values for FEV1 and FEV1/FVC in all participants and for FEV1/FVC in ever-smokers (Figure 1). The plot of FEV1 in ever-smokers, however, shows slight deviations for high signal SNPs. The genomic inflation factor, λ for FEV1 is 0.83 in all individuals and 1.05 in smokers; λ for FEV1/FVC in all individuals is 0.92 and 1.13 in smokers.
