Diagnostic performance of FEV ₁ /FEV ₆ in detecting airway obstruction and chronic obstructive pulmonary disease: A systematic review and meta-analysis

BackgroundAlthough the postbronchodilator FEV₁/FVC is the gold standard for diagnosing COPD, it is not easily obtainable due to various reasons. This study aims to investigate whether FEV₁/FEV₆ may serve as an easily accessible surrogate for FEV₁/FVC in detecting airway obstruction and COPD.MethodsEligible articles were screened from PubMed, Web of Science and Scopus. The Quality Assessment of Diagnostic Accuracy Studies-2 was applied for quality assessment. The pooled sensitivity, specificity, and area under the curve (AUC) of the summary receiver operating curve were calculated to evaluate the diagnostic performance of FEV₁/FEV₆ in detecting airway obstruction and COPD and to determine the optimal cutoff value. Sensitivity analyses, subgroup analyses and meta-regression were performed to explore the source of heterogeneity.ResultsWith 28 eligible articles and 65,744 subjects, the FEV₁/FEV₆ ratio showed good diagnostic performance in detecting both airway obstruction (sensitivity: 0.87, specificity: 0.94, AUC 0.95) and COPD (sensitivity: 0.83, specificity: 0.88, AUC 0.91). Further analyses of the optimal cutoff value suggested that an FEV₁/FEV₆<0.72 was the best criterion for detecting airway obstruction (sensitivity: 0.84, specificity: 0.97, AUC 0.96), whereas an FEV₁/FEV₆<0.74 was the best criterion for detecting COPD (sensitivity: 0.87, specificity: 0.89, AUC 0.93). The results of subgroup analyses and meta-regression suggested that study design and geographical location may affect the heterogeneity of both sensitivity and specificity in detecting airway obstruction and COPD.ConclusionThe FEV₁/FEV₆ may serve as an easily accessible alternative in detecting airway obstruction and COPD. However, application of FEV₁/FEV₆ may also be constrained by availability and affordability of devices. Further studies are required to determine the best-suited population for FEV₁/FEV₆ application.