Real-life evaluation of novel forced expiratory ratios with asthma exacerbations and symptoms

TY - JOUR

T1 - Real-life evaluation of novel forced expiratory ratios with asthma exacerbations and symptoms

AU - Paterson, Fraser

AU - On, Jing Yuan

AU - Ahmed, Dania

AU - Poto, Remo

AU - Bhattacharjee, Atanu

AU - Greig, Robert

AU - Brown, Jake

AU - de Jongh, Frans

AU - Diamant, Zuzana

AU - Fardon, Tom

AU - Lipworth, Brian

AU - Chan, Rory

N1 - Publisher Copyright: © 2025 The Authors.

PY - 2025/12

Y1 - 2025/12

N2 - Background Small airway dysfunction is an important treatable trait in persistent asthma but remains poorly captured by conventional spirometry. The (forced expiratory volume in 3 seconds [FEV 3]-FEV 1)/forced vital capacity (FVC) and FEV 3/FEV 6 ratios have been proposed as novel markers of peripheral airflow limitation. Objective To investigate the relationship between (FEV 3-FEV 1)/FVC and FEV 3/FEV 6 with symptom control and the frequency of severe exacerbations in patients with moderate-to-severe asthma. Methods Clinical, physiological, and biomarker data were collected from adults with Global Initiative for Asthma–defined moderate-to-severe asthma visiting a specialist severe asthma center in Scotland, United Kingdom. Associations between spirometric and oscillometric parameters with clinically relevant outcomes were retrospectively analyzed using multivariate models. Results A total of 294 patients were included in the analysis. The (FEV 3-FEV 1)/FVC and FEV 3/FEV 6 ratios were not significantly associated with asthma symptoms or severe exacerbation rates. Conversely, traditional measures such as FEV 1/FVC (adjusted odds ratio [95% CI], 2.11 [1.27-3.50]; P < .01), forced expiratory flow rate between 25% and 75% of the FVC/FVC (2.11 [1.27-3.50]; P < .01), and oscillometric Rrs 5-20 (1.90 [1.14-3.16]; P < .05) were significantly associated with more than or equal to 2 exacerbations in the previous year. High coefficient of determination ( r 2) values were observed between FEV 1/FVC with (1) (FEV 3-FEV 1)/FVC ( r 2 = 0.61) and (2) FEV 3/FEV 6 ( r 2 = 0.83), suggesting overlapping aspects of lung function being measured. There was a weak correlation between FEV 1/FVC and Rrs 5-20 values ( r 2 = 0.08) indicating that these parameters assess unique aspects of lung function and mechanics. Conclusion In moderate-to-severe asthma, the (FEV 3–FEV 1)/FVC and FEV 3/FEV 6 ratios were not independently associated with exacerbation risk or symptom control and did not provide additional clinical value compared with conventional lung function measures.

AB - Background Small airway dysfunction is an important treatable trait in persistent asthma but remains poorly captured by conventional spirometry. The (forced expiratory volume in 3 seconds [FEV 3]-FEV 1)/forced vital capacity (FVC) and FEV 3/FEV 6 ratios have been proposed as novel markers of peripheral airflow limitation. Objective To investigate the relationship between (FEV 3-FEV 1)/FVC and FEV 3/FEV 6 with symptom control and the frequency of severe exacerbations in patients with moderate-to-severe asthma. Methods Clinical, physiological, and biomarker data were collected from adults with Global Initiative for Asthma–defined moderate-to-severe asthma visiting a specialist severe asthma center in Scotland, United Kingdom. Associations between spirometric and oscillometric parameters with clinically relevant outcomes were retrospectively analyzed using multivariate models. Results A total of 294 patients were included in the analysis. The (FEV 3-FEV 1)/FVC and FEV 3/FEV 6 ratios were not significantly associated with asthma symptoms or severe exacerbation rates. Conversely, traditional measures such as FEV 1/FVC (adjusted odds ratio [95% CI], 2.11 [1.27-3.50]; P < .01), forced expiratory flow rate between 25% and 75% of the FVC/FVC (2.11 [1.27-3.50]; P < .01), and oscillometric Rrs 5-20 (1.90 [1.14-3.16]; P < .05) were significantly associated with more than or equal to 2 exacerbations in the previous year. High coefficient of determination ( r 2) values were observed between FEV 1/FVC with (1) (FEV 3-FEV 1)/FVC ( r 2 = 0.61) and (2) FEV 3/FEV 6 ( r 2 = 0.83), suggesting overlapping aspects of lung function being measured. There was a weak correlation between FEV 1/FVC and Rrs 5-20 values ( r 2 = 0.08) indicating that these parameters assess unique aspects of lung function and mechanics. Conclusion In moderate-to-severe asthma, the (FEV 3–FEV 1)/FVC and FEV 3/FEV 6 ratios were not independently associated with exacerbation risk or symptom control and did not provide additional clinical value compared with conventional lung function measures.

KW - asthma

KW - spirometry ratio

KW - oscillometry

KW - exacerbations

KW - symptom control

U2 - 10.1016/j.anai.2025.08.015

DO - 10.1016/j.anai.2025.08.015

M3 - Article

C2 - 40886771

SN - 1081-1206

VL - 135

SP - 663-667.e1

JO - Annals of Allergy, Asthma and Immunology

JF - Annals of Allergy, Asthma and Immunology

IS - 6

ER -