Introduction: The ERS/ATS task force recommended in 2022 a new threshold for defining bronchodilator responsiveness2. This study focuses on comparing bronchodilator responsiveness as defined in the ERS/ATS recommendation from 2005 (increase in FEV1 or FVC > 200 ml and >12% from baseline) versus the 2022 recommendation (increase in FEV1>10% predicted)1,2
Methods: Data was obtained from a retrospective study, performed in a general hospital. 750 patients performed pre and post (after administration of 400 ug salbutamol) spirometry. In this group 201 patients with a FER < LLN were selected and included in the present analysis. Classification of bronchodilator response was performed using either the cut-off values from Pellegrino et al. or Stanojevic et al1,2
Statistics: Differences between ratings of bronchodilator response were evaluated using the chi-square test with SPSS (version 28.0) and P value of 0.05. Data are expressed as mean ± S.D. 
Results: The patient group  consisted  of 103 males and 98 females, with a mean age of 62 years (± 12). Further characteristics are: mean FER (0.52 ± 11%), mean FEV1%pred (63 ± 17%) and mean FEV1post (1.86L ± 0.68L). From these 201 patients, 53 patients showed bronchodilator responsiveness according to the 2005 recommendations. However, when applying the cut-off values from the 2022 recommendations, the amount of patients decreased to 30, leading to a reclassification of  bronchodilator responsiveness in 23 patients (43%, p < 0.001). 
Conclusion: Applying the new recommendations for defining bronchodilator responsiveness in this patient group with airflow limitation compared to the recommendations from 2005, result in a significant reduction.