[Comparison of positive criteria for ATS/ERS bronchodiastolic tests in 2005 and 2021 with different degree of airway obstruction].

<b>Objective:</b> To compare the consistency of the positive criteria for bronchial dilation tests of the American Thoracic Society and the European Respiratory Society (ATS/ERS) in 2005 and 2021 (referred to as the 2005 standard and the 2021 standard), and explore the influence of different degrees of airway obstruction on the differences in the results determined by the two standards. <b>Methods:</b> A retrospective analysis was conducted on the data of 9 189 subjects aged 18 to 92 (60.6±13.1) years who underwent bronchial dilation tests in the Pulmonary Function Laboratory of China-Japan Friendship Hospital from May 2023 to May 2024, including 5 704 males and 3 485 females. The positive rates of bronchial dilation tests under the two standards for subjects with different degrees of airway obstruction were calculated respectively, and the consistency of the determination results was analyzed. <b>Results:</b> Among the 9 189 subjects, 1 771 (19.3%) were positive by the 2005 criteria and 1 581 (17.2%) by the 2021 criteria. Of the 7 454 subjects with varying degrees of obstructive ventilatory dysfunction, there were 4 350 mild, 860 moderate, 702 moderate to severe, 862 severe, and 680 very severe obstruction cases, respectively. Using FEV₁ as the judgment criterion, the positive rates of the 2005 criteria for moderate to very severe obstruction were 28.8% (248 cases), 32.1% (225 cases), 29.6% (255 cases), and 17.4% (118 cases), respectively, which were higher than those of the 2021 criteria [20.9% (180 cases), 19.5% (137 cases), 16.5% (142 cases), and 6.0% (41 cases), all <i>P</i><0.001]. Using FVC as the judgment criterion, the positive rates of the 2005 criteria for mild and moderate obstruction were 3.4% (147 cases) and 15.9% (137 cases), respectively, which were lower than those of the 2021 criteria [6.0% (261 cases) and 18.6% (160 cases), both <i>P</i><0.001], but higher rates were detected for severe and very severe obstruction [32.3% (278) and 45.6% (310) vs 29.7% (256) and 34.1% (232), respectively; both <i>P</i><0.001]. Using FEV₁ and/or FVC as the judgment criteria, the positive rates of the 2005 criteria for moderate to very severe obstruction were 33.5% (288 cases), 38.9% (273 cases), 42.5% (366 cases), and 49.3% (335 cases), respectively, which were higher than those of the 2021 criteria [28.0% (241 cases), 28.9% (203 cases), 33.2% (286 cases), and 34.9% (237 cases), all <i>P</i><0.001]. The results of the two criteria were consistent in 8 623 subjects (93.8%) (Kappa=0.794, <i>P</i><0.001). <b>Conclusion:</b> The overall agreement between the 2005 and 2021 criteria is good. Among patients with moderate to very severe airway obstruction, the 2021 criteria demonstrates consistently lower positive rates compared to the 2005 criteria, with this discrepancy being particularly evident when FEV₁ was used as the diagnostic criterion.