ArticleScientific reports2019
The Concavity of the Maximal Expiratory Flow-Volume Curve Reflects the Extent of Emphysema in Obstructive Lung Diseases.
Article in Scientific reports, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
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10 citing papers in PubMed, 9 citations in OpenAlex.
- Emphysema Severity Index: a new spirometric parameter in epidemiology.ERJ open research · 2026Article
- Morphological Analysis of the Flow-Volume Curve for Identifying Fixed Airflow Obstruction: A Scoping Review.Advances in respiratory medicine · 2026Article
- Reply: An index of maximal expiratory flow-volume curve with different features related to central and peripheral concavity.ERJ open research · 2026Article
- An index of maximal expiratory flow-volume curve with different features related to central and peripheral concavity.ERJ open research · 2026Article
- Article
- Curve-Modelling and Machine Learning for a Better COPD Diagnosis.International journal of chronic obstructive pulmonary disease · 2024Observational
- Systems Engineering Approach to Modeling and Analysis of Chronic Obstructive Pulmonary Disease.ACS omega · 2023Article
- Principal component analysis of flow-volume curves in COPDGene to link spirometry with phenotypes of COPD.Respiratory research · 2023Article
- The Challenges of Spirometric Diagnosis of COPD.Canadian respiratory journal · 2023Review
- Pulmonary function testing in COPD: looking beyond the curtain of FEV1.NPJ primary care respiratory medicine · 2021Review
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Authors and funding
15 authors at 4 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
A concave-shaped maximal expiratory flow-volume (MEFV) curve is a spirometric feature in chronic obstructive pulmonary disease (COPD). The MEFV curve is characterized by an increase in the Obstructive Index, which is defined as a ratio of forced vital capacity to the volume-difference between two points of half of the peak expiratory flow on the MEFV curve. We hypothesized that the Obstructive Index would reflect the severity of emphysema in patients with COPD and asthma-COPD overlap (ACO). Thus, the aim of this retrospective study was to evaluate whether the Obstructive Index on spirometry is associated with the extent of emphysema on computed tomography (CT) in patients with COPD, ACO, and asthma (N = 65, 15, and 53, respectively). The percentage of low-attenuation volume (LAV%) and wall area (WA%) were measured on CT. The Obstructive Index was higher in patients with COPD and ACO than in those with asthma. Spearman correlation showed that a greater Obstructive Index was associated with a higher LAV%, but not WA%. Multivariate analysis showed that Obstructive Index was associated with LAV% (standardized β = 0.43, P < 0.0001) independent of other spirometric indices. The Obstructive Index is a useful spirometric index that reflects the extent of emphysema.
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