Prevalence, Diagnostic Utility and Associated Characteristics of Bronchodilator Responsiveness

Abstract

Rationale: The prevalence and diagnostic utility of bronchodilator responsiveness (BDR) in a real-life setting is unclear. Objective: To explore this uncertainty in patients aged ⩾12 years with physician-assigned diagnoses of asthma, asthma and chronic obstructive pulmonary disease (COPD), or COPD in NOVELTY, a prospective cohort study in primary and secondary care in 18 countries. Methods: The proportion of patients with a positive BDR test in each diagnostic category was calculated using 2005 (ΔFEV₁ or ΔFVC ⩾12% and ⩾200 ml) and 2021 (ΔFEV₁ or ΔFVC >10% predicted) European Respiratory Society/American Thoracic Society criteria. Measurements and Main Results: We studied 3,519 patients with a physician-assigned diagnosis of asthma, 833 with a diagnosis of asthma + COPD, and 2,436 with a diagnosis of COPD. The prevalence of BDR was 19.7% (asthma), 29.6% (asthma + COPD), and 24.7% (COPD) using 2005 criteria and 18.1%, 23.3%, and 18.0%, respectively, using 2021 criteria. Using 2021 criteria in patients diagnosed with asthma, BDR was associated with higher fractional exhaled nitric oxide; lower lung function; higher symptom burden; more frequent hospital admissions; and greater use of triple therapy, oral corticosteroids, or biologics. In patients diagnosed with COPD, BDR (2021) was associated with lower lung function and higher symptom burden. Conclusions: BDR prevalence in patients with chronic airway diseases receiving treatment ranges from 18% to 30%, being modestly lower with the 2021 than with the 2005 European Respiratory Society/American Thoracic Society criteria, and it is associated with lower lung function and greater symptom burden. These observations question the validity of BDR as a key diagnostic tool for asthma managed in clinical practice or as a standard inclusion criterion for clinical trials of asthma and instead suggest that BDR be considered a treatable trait for chronic airway disease.

Keywords: BDR; asthma; chronic obstructive pulmonary disease; diagnosis.

Figure 1.

(A–C) Prevalence of bronchodilator responsiveness (BDR) according to different BDR definitions among patients with physician-assigned asthma, COPD, or both. COPD = chronic obstructive pulmonary disease; pred = predicted.

Figure 2.

(A–C) Relative change in FEV₁ post-bronchodilator (post-BD) and frequency in bronchodilator responsiveness (BDR) positive patients by pre-BD FEV₁ percent predicted, defining BDR positive as post-BD ΔFEV₁ or ΔFVC >10% predicted (European Respiratory Society/American Thoracic Society 2021 criteria). The columns show the median change in FEV₁ (ml) after BD (BDR). The vertical dotted lines correspond to the interquartile range. The red line and percentages correspond to the proportions of patients meeting BDR positive criteria defined as ΔFEV₁ or ΔFVC >10% predicted. The numbers in parentheses correspond to (min-max) for each decile of pre-BD FEV₁ % predicted. COPD = chronic obstructive pulmonary disease; pred = predicted.

Figure 3.

Odds ratios for the association of clinical characteristics with BDR in patients with physician diagnosed asthma or COPD. ORs are derived from a logistic regression model with the BDR as the outcome and the clinical characteristic as the predictor (no covariate adjustments). BDR = bronchodilator responsiveness; CI = confidence interval; EOS = eosinophils; Fe_NO = fractional exhaled nitric oxide; mMRC = modified Medical Research Council; ORs = odds ratios.