Figure 4
From: COPD diagnosis related to different guidelines and spirometry techniques
A. Difference between pre-bronchodilator slow (SVC) and forced (FVC) vital capacity related to FEV1 as percent of predicted value prior to bronchodilatation in 3881 smokers. Due to difficulties in taking instructions or technical errors data from 6 spirometries were not included in the analyses which thus are based on 3881 and not 3887 smokers. B. Difference between post-bronchodilator slow (SVC) and forced (FVC) vital capacity related to FEV1 as percent of predicted value after bronchodilatation in 1574 smokers with a pre-bronchodilator FEV1/VC -ratio below 0.75. Due to unacceptable measurements or technical errors data from 3 spirometries were not included in the analyses which thus is based on 1574 and not 1577 smokers.