Evidence map›Paper›PMID 39751890›Full record

ArticleLung2025

The Characteristics of the Concavity of Descending Limb of Maximal Expiratory Flow-Volume Curves Generated by Spirometry.

Zhufeng Wang, Lina Liang, Feifei Huang, Kang Peng, Junfeng Lin, Yi Gao, Jinping Zheng

Abstract read
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In one paragraph

Article in Lung, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

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.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Zhufeng Wang *National Clinical Research Center for Respiratory Disease, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Lina Liang *National Clinical Research Center for Respiratory Disease, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Feifei Huang *National Clinical Research Center for Respiratory Disease, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Kang PengNational Clinical Research Center for Respiratory Disease, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Junfeng LinNational Clinical Research Center for Respiratory Disease, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Yi GaoNational Clinical Research Center for Respiratory Disease, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China. misstall2@163.com.
Jinping ZhengNational Clinical Research Center for Respiratory Disease, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China. jpzhenggy@163.com.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThis study examined the concavity (angle β, central and peripheral concavity) of the descending limb of the maximal expiratory flow-volume (MEFV) curves to reflect various ventilatory defects, including obstructive, restrictive, or mixed patterns.

methodsWe conducted a cross-sectional study collecting spirometry data from a healthcare center and a tertiary hospital between 2017 and 2022, with additional raw flow-volume curve data from primary healthcare institutions in 2023. We analyzed differences in concavity between spirometric patterns. Receiver operating characteristic curves were used to assess the predictive power of concavity for spirometric patterns. The relationship among concavity indices was examined.

resultsThis study included 18,938 cases, with 22% exhibiting an obstructive pattern. The dataset comprised 14,868 cases for training, 3716 cases for validation, and 354 cases for testing. In the training set, the mean angle β were 180.3 ± 12.4 and 148.5 ± 12.7 degrees in normal and obstruction patterns. The angle β had an AUC of 0.970 (95% CI 0.966-0.973) for identifying normal and obstructive patterns, with a cut-off value of 163.0 degrees. In the validation set, out of 2311 cases with a normal forced vital capacity (FVC), 3.1% cases exhibited a Z-score of forced expiratory volume in 1 s to FVC ratio (FEV

conclusionThe concavity of the descending limb of MEFV curves may be crucial in identifying spirometric patterns.

Indexed as

SpirometryAdultAgedCross-Sectional StudiesFemaleForced Expiratory VolumeHumansLungMaleMaximal Expiratory Flow-Volume CurvesMiddle AgedROC CurveVital CapacityAirway obstructionsCross-sectional studiesMaximal expiratory flow-volume curvesSpirometry

Identifiers

PMID39751890

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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.