Diagnostic Accuracy of Bronchodilator Response for Asthma in a Population of South China.

INTRODUCTION: A significant bronchodilator response is commonly defined as a 12% or greater and 200 ml or greater change in FEV1 from baseline according to the 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) criterion. A number of studies have shown that the ATS/ERS criterion has limitations in asthma diagnosis, and some experts have argued for correcting the criteria. The aim of this study is to investigate the diagnostic value of acute bronchodilator response for asthma in a Southern Chinese population.

METHODS: We prospectively evaluated 805 patients with obstructive lung disease (309 for asthma, 496 for non-asthma). Spirometry was performed according to the ATS/ERS guidelines. Data were analyzed by SPSS 18.0. The receiver-operating characteristic (ROC) curve was drawn to assess the diagnostic accuracy of the ATS/ERS criterion based on FEV1 . Linear regression was used to analyze the factors of FEV1 change.

RESULTS: The sensitivity and specificity of the acute bronchodilator test when judged by the ATS/ERS criteria (200 ml or higher and 12% improvement) were 68.6% and 78.2%, respectively. For the ATS/ERS criteria, the Youden Index, which comprehensively reflects the authenticity of a diagnostic test, was 46.8%. The absolute change of FEV1 positively correlated with baseline FEV1 and weight and negatively with age, while the percentage change of FEV1 was negatively correlated with baseline FEV1 , age and height and positively with weight. Compared with the different diagnostic values, when ∆FEV1 was 195 ml and ∆FEV1i % was 14%, the Youden Index was the largest (48.2%) and the diagnostic capability of the test the biggest.

CONCLUSIONS: The ATS/ERS criterion for acute bronchodilator response might not be completely suitable for asthma in the Chinese population.

TRIAL REGISTRATION: Chinese Clinical Trial Registry (Registry ID: ChiCTR-DDT-14004976).

FUNDING: This work was supported by the National Natural Science Foundation of China (grant nos. 81670027, 81270080).