Angle β combined with FeNO and FEV1/FVC% for the detection of asthma in school-aged children

Abstract

Objective:

The diagnostic value of angle β in school-aged children with asthma is unknown. We speculate that angle β may reflect diversification of the forced expiratory flow (FEF) to some extent. The objective of this study was to assess the diagnostic accuracy of angle β, FeNO, pulmonary function parameters and their combinations for asthma in school-aged children.

Methods:

In total, 248 children participated in this study (140 children with asthma and 108 healthy children). The diagnostic performance of angle β, FeNO and pulmonary function parameters was determined using receiver operating characteristic (ROC) curves. In the ROC analysis, we used the hold out cross-validation method to avoid overfitting. This study was performed in China and followed the Guidelines for the diagnosis and optimal management of asthma in children (China).

Results:

1) In the asthma group, the mean angle β value was significantly smaller than that in the control group (P < 0.001), but the mean FeNO value was significantly higher than that in the control group (P < 0.001). 2) More acute exacerbation or greater severity corresponded to a smaller angle β. 3) Among the single indices, the area under the ROC curve of angle β was the largest (except for FEV1/FVC%). For combined indicators, after cross-verification, the combination of angle β, FEV1/FVC% and FeNO showed the highest diagnostic accuracy.

Conclusion:

Angle β combined with FeNO and FEV1/FVC% can improve the diagnostic accuracy for asthma in school-aged children.

Keywords:

• Pulmonary function testing
• maximal expiratory flow-volume curve
• pulmonary function parameters
• receiver operating characteristic curve
• diagnosis

Declaration of interest

There are no conflicts of interest related to the content of this paper to report.

Authors’ contributions

Yanli Zhang was responsible for the study design, data analysis, manuscript preparation and revising the manuscript. Hongke Shi carried out the literature search, data collection, data analysis and the manuscript preparation. Aifang Su, Fuli Dai, Yuehong Zheng and Chunling Cai participated in the data collection. Xiufang Wang and Yan Zhang participated in the manuscript review. Xiao Wang carried out the literature search. All authors have read and approved the manuscript.