Impact of new positive bronchodilator test criteria

<bold>Background:</bold> According to 2005 ERS/ATS interpretative strategies, a positive bronchodilator response (BDR+) was considered an improvement of at least 200ml and 12% in FEV1 or FVC over baseline, using this improvement in FEV1 for the diagnosis of asthma. However, as a result of the change in the criteria for its diagnosis according to the GEMA 5.3 guideline, BDR+ is considered an improvement of 10% of the relationship in terms. Of the reference value to the old criteria already mentioned. <bold>Aim:</bold> Compare spirometry with positive bronchodilator using the old and/or new criteria. <bold>Methods:</bold> Prospective study of 500 spirometries collected through a telemedicine program (June 2023-October 2023) with positive bronchodilator response by old or new criteria for FEV1. <bold>Results:</bold> Clinical and functional characteristics of patients summarized in Table 1. Of the 500 BDR+ spirometries collected, 380 (76%) were positive for both criteria, so 24% (120) were only positive for one or the other condition. 72 spirometries (14%) new positive according to old diagnostic criteria and 48 (10%) according to new diagnostic criteria (Table 2) <fig><object-id>erj;64/suppl_68/PA409/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Conclusions:</bold> Proportion of BDR+ spirometries with new 2021 ERS/ATS interpretative strategies is markedly reduced, to almost 5%. This could modify our functional diagnoses.