Figure 1From: Association between occupational exposure and the clinical characteristics of COPD Main differences between VDGF + and VDGF- COPD patients. All differences are significant at the p < 0.05 level except life time asthma (p = 0.06) and FEV1(p = 0.08). Reported definitive and transient interruptions of work are those related to respiratory problems.Back to article page