Should FEV1/FEV6 Replace FEV1/FVC Ratio To Detect Airway Obstruction? Ji-yong Jing, MD, Tian-cha Huang, MD, Wei Cui, MD, Feng Xu, MD, Hua-hao Shen, MD, PhD, FCCP  CHEST  Volume 135, Issue 4, Pages 991-998 (April 2009) DOI: 10.1378/chest.08-0723 Copyright © 2009 The American College of Chest Physicians Terms and Conditions

Figure 1 Study identification, inclusion, and exclusion for metaanalysis. CHEST 2009 135, 991-998DOI: (10.1378/chest.08-0723) Copyright © 2009 The American College of Chest Physicians Terms and Conditions

Figure 2 Forest plot of sensitivity and specificity for FEV1/FEV6 in the diagnosis of airway obstruction. Pooled estimates for FEV1/FEV6 are as follows: sensitivity, 0.89 (95% CI, 0.83 to 0.93); specificity, 0.98 (95% CI, 0.95 to 0.99). df = degrees of freedom. CHEST 2009 135, 991-998DOI: (10.1378/chest.08-0723) Copyright © 2009 The American College of Chest Physicians Terms and Conditions

Figure 3 SROC curve for FEV1/FEV6; line indicates regression; area under the curve (AUC), 0.97 (95% CI, 0.95 to 0.98); Q *= 0.95; n = 11 studies. SENS = sensitivity; SPEC = specificity. CHEST 2009 135, 991-998DOI: (10.1378/chest.08-0723) Copyright © 2009 The American College of Chest Physicians Terms and Conditions

Figure 4 Funnel graph for the assessment of potential publication bias in FEV1/FEV6. The funnel graph plots the log of the DOR against the SE (s.e.) of the log of the DOR. The dashed line indicates 95% confidence limits of the log of the DOR. The funnel plots show approximate symmetry. The result of the Egger test for publication bias was not significant (p = 0.111). CHEST 2009 135, 991-998DOI: (10.1378/chest.08-0723) Copyright © 2009 The American College of Chest Physicians Terms and Conditions