Prevalence of Bronchodilator response in a general population - Data from the Austrian LEAD cohort

Bronchodilator response (BDR) testing is commonly used to assess any improvement of spirometric measurements after beta agonist inhalation. In the 2005 ATS/ERS defined a positive BDR in adults as an increase of FEV1 or FVC>200ml and 12% (BDR 2005). Recently a new definition was recommended by the ATS/ERS, defining the improvement of FEV1 or FVC>10% compared to the predicted value as positive (BDR 2021), accounting more accurately for sex, age and height. We analysed the prevalence of positive BDR for both definitions using the Austrian general population LEAD cohort including participants aged 18-82 years. All subjects (11,638; 52.8% females) with valid pre- and post-BD spirometry were included. The prevalence of the BDR 2005 & 2021 definitions were 458 (4.0%) and 484 (4.2%), respectively. Using BDR 2021 resulted in higher, rates of positivity in females and in neversmokers, while using BDR 2005 led to higher numbers in participants with airway obstruction (FEV1/FVC<LLN) and lower FEV1 (Table1). Only the latter two parameters were statistically significant. Both definitions detected similar prevalence of positive BDR. The 2021 definition demonstrates a lower dependency on male sex and low baseline FEV1, at the same time including more subjects without spirometric obstruction and no history of smoking. This could lead to earlier detection of airway changes especially in individuals with high FEV1 or FVC.