ArticleInternational journal of chronic obstructive pulmonary disease2016
Computer quantification of "angle of collapse" on maximum expiratory flow volume curve for diagnosing asthma-COPD overlap syndrome.
Article in International journal of chronic obstructive pulmonary disease, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
12 citing papers in PubMed, 17 citations in OpenAlex.
- Emphysema Severity Index: a new spirometric parameter in epidemiology.ERJ open research · 2026Article
- Article
- Parameter D: New Measure of Airflow Obstruction.Annals of the American Thoracic Society · 2023Article
- The Role of Pulmonary Function Testing in the Diagnosis and Management of COPD.Respiratory care · 2023Review
- Deep neural network analyses of spirometry for structural phenotyping of chronic obstructive pulmonary disease.JCI insight · 2020Article
- Validation of a method to assess emphysema severity by spirometry in the COPDGene study.Respiratory research · 2020Article
- The Concavity of the Maximal Expiratory Flow-Volume Curve Reflects the Extent of Emphysema in Obstructive Lung Diseases.Scientific reports · 2019Article
- Spirometric indices of early airflow impairment in individuals at risk of developing COPD: Spirometry beyond FEVRespiratory medicine · 2019Review
- The Peak Index: Spirometry Metric for Airflow Obstruction Severity and Heterogeneity.Annals of the American Thoracic Society · 2019Observational
- New Spirometry Indices for Detecting Mild Airflow Obstruction.Scientific reports · 2018Article
- Impact of COPD on prognosis of lung cancer: from a perspective on disease heterogeneity.International journal of chronic obstructive pulmonary diseaseArticle
- The link between chronic obstructive pulmonary disease phenotypes and histological subtypes of lung cancer: a case-control study.International journal of chronic obstructive pulmonary diseaseArticle
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundIn a previous study, we demonstrated that asthma patients with signs of emphysema on quantitative computed tomography (CT) fulfill the diagnosis of asthma-COPD overlap syndrome (ACOS). However, quantitative CT measurements of emphysema are not routinely available for patients with chronic airway disease, which limits their application. Spirometry was a widely used examination tool in clinical settings and shows emphysema as a sharp angle in the maximum expiratory flow volume (MEFV) curve, called the "angle of collapse (AC)". The aim of this study was to investigate the value of the AC in the diagnosis of emphysema and ACOS.
methodsThis study included 716 participants: 151 asthma patients, 173 COPD patients, and 392 normal control subjects. All the participants underwent pulmonary function tests. COPD and asthma patients also underwent quantitative CT measurements of emphysema. The AC was measured using computer models based on Matlab software. The value of the AC in the diagnosis of emphysema and ACOS was evaluated using receiver-operating characteristic (ROC) curve analysis.
resultsThe AC of COPD patients was significantly lower than that of asthma patients and control subjects. The AC was significantly negatively correlated with emphysema index (EI;
conclusionThe AC on the MEFV curve quantified by computer models correlates with the extent of emphysema. The AC may become a surrogate marker for the diagnosis of emphysema and help to diagnose ACOS.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.