Bronchiectasis as a Treatable Phenotype Among Acute COPD Admissions in an Irish Tertiary Referral Centre

Presenter: Jack McCarthy.

Coexisting bronchiectasis is common among patients presenting with COPD exacerbations and may influence sputum microbiology and treatment decisions. This single-centre observational study assessed patients visiting to the emergency department with COPD between July 2024–July 2025. Among 292 patients, 436 hospital admissions occurred, with 16% (n=47) having combined COPD and bronchiectasis (combined group). Mean length of stay was 7.67 days in the combined group versus 7.01 days in the COPD-alone group, while mortality was 21% (n=10) and 19% (n=47), in the combined and COPD-alone group respectively. Pseudomonas and Staphylococcus aureus were isolated in 21% (n=10) and 17% (n=8) of the combined group versus 5% (n=13) and 4% (n=10) in the COPD group. Long-term azithromycin was prescribed in 38% (n=18) of the combined group patients versus 15% (n=37) in the COPD-alone group, while nebulized antibiotics were used in 6% (n=3) versus <1% (n=2). Thus, coexisting bronchiectasis identified a treatable phenotype with different microbiological and treatment characteristics, despite similar short-term LOS and mortality.

Burden of Chronic Obstructive Pulmonary Disease and Its Attributable Risk Factors in the World’s Ten Most Populous Countries, 1990–2023: A Retrospective Cross-Sectional

Presenter: Jisong Yan.

COPD burden has declined globally, but substantial differences persist across the world’s ten most populous countries in disease burden and attributable risk profiles. Using GBD 2023 data, this retrospective cross-sectional study assessed age-standardised disability-adjusted life-year (ASDR) rates from 1990–2023 and examined trends by sex, country, and risk factor using Join-point regression and annual percentage changes. Global COPD ASDR declined from 947.4 to 585.1 per 100,000, with China showing the largest reduction (EAPC: −3.99%), driven primarily by improved air quality and reduced household biomass use. Bangladesh had the highest 2023 burden (ASR: 2198.5 per 100,000), while second-hand smoke-attributable burden among females increased (EAPC: 0.19%). Although smoking remained the leading global risk factor, its attributable fraction fell from 45% to 32%, alongside increasing contributions from ambient ozone, non-optimal temperatures, and household air pollution, particularly among females in low-SDI settings such as India and Nigeria. These findings highlight a shifting COPD risk landscape, with pollution, environmental, occupational, and climate-related exposures becoming increasingly important alongside smoking, underscoring the need for country-, sex-, and exposure-specific public health strategies.

Closing The Diagnostic Gap: A Multidimensional Approach to Reclassifying PRISm and Pre-COPD Individuals into COPD

Presenter: Cristian Amaral De Sousa.

Underdiagnosis of COPD remains particularly relevant among individuals with PRISm and pre-COPD patterns, where spirometry alone may not capture the disease heterogeneity. A cross-sectional, retrospective study evaluated a multidimensional diagnostic scheme integrating spirometric, radiological and symptomatic measures in 48 PRISm and pre-COPD patients assessed at Hospital Universitario Príncipe de Asturias between Nov 2023–Oct 2025. The multidimensional approach identified 45 COPD cases compared with the classical FEV₁/FVC <0.70 criterion (χ²=28, p<0.001). CAT score was the only significant predictor of reclassification (p=0.026), while structural abnormalities and (mMRC) dyspnoea were not significant predictors. Diagnostic performance was excellent (AUC=0.83). Although the standard 0.50 threshold provided specificity of 1.00, sensitivity was 0.00; the Youden index identified 0.30 as optimal, yielding sensitivity 0.67 and specificity 0.87 and correctly classifying 30 of 45 cases. These findings support a multidimensional approach to COPD case identification in PRISm and pre-COPD, suggesting that symptom assessment with CAT may offer greater incremental value for reclassification than radiological assessment alone.

Comparative Effects of Triple Inhaled Therapy with Budesonide/Glycopyrronium/Formoterol Versus Fluticasone Furoate/Umeclidinium/Vilanterol on Small Airway Disease in COPD Patients: A Randomized Crossover Study

Presenter: MD Peerawat Kaewkeeyoon.

Small airway dysfunction represents a clinically relevant aspect of COPD and may be influenced by inhaled triple therapy. This randomized crossover-controlled trial compared budesonide/glycopyrronium/formoterol (BGF) with fluticasone furoate/umeclidinium/vilanterol (FUV). Following a 1-week washout, patients were randomized to receive either BGF or FUV for 4 weeks, followed by a second 1-week washout and crossover to the alternate treatment for another 4 weeks. Small airway function was assessed using FEF25-75 and impulse oscillometry (IOS), alongside mMRC and CAT scores. Among 22 patients who completed the study, mean age was 67.3±7.7 years and mean FEV₁ was 69.4±18.8% predicted. No significant between-treatment differences were observed in any small airway parameter, and adverse events were comparable. BGF significantly improved FEF25-75, mMRC and CAT scores, while FUV significantly improved R5-R20, area of reactance (Ax), resonant frequency and CAT scores after treatment. Overall, both regimens improved small airway function and clinical symptoms, with no significant differences between treatments. Larger, longer-term studies are needed to determine whether clinically meaningful differences emerge with prolonged treatment.

Comparative Efficacy of Once-Daily LAMA/LABA Combinations Versus Tiotropium on Constant-Work-Rate Cycle Endurance in COPD: A Randomized Crossover Pilot Study (COMPETE)

Presenter: Jakub Mróz.

Exercise intolerance is a major burden in COPD, while comparative evidence on the effects of different bronchodilators on constant-work-rate cycle endurance remains limited. The COMPETE randomized, open-label crossover pilot study evaluated 16 patients with stable GOLD II–III COPD who received tiotropium/olodaterol, umeclidinium/vilanterol, indacaterol/glycopyrronium, and tiotropium for 28 days each, separated by 7-day washout periods. Constant-work-rate cycle ergometry (CWRCE) was performed at 80% peak work rate. No significant difference in change in endurance time (ΔET) was observed across treatments (p=0.169). Median ΔET was +30s with umeclidinium/vilanterol, +2s with tiotropium/olodaterol, +14s with indacaterol/glycopyrronium, and -30s with tiotropium. Exploratory analysis showed an adjusted difference of +89.6s (95%CI 11.5-167.6) for umeclidinium/vilanterol versus tiotropium. Clinically important improvement (≥60s) occurred in 40% with umeclidinium/vilanterol or tiotropium/olodaterol versus 20% with tiotropium. FEV₁ improved significantly with umeclidinium/vilanterol (+0.10L, p=0.006) and tiotropium/olodaterol (+0.21L, p=0.021; global p=0.028), while VO₂peak increased significantly only with tiotropium/olodaterol (+92.9mL/min, 95%CI 1.3-184.6). No new safety signals emerged. The findings suggest that CWRCE may be a useful tool for comparing bronchodilator effects, with interpatient variability warranting further study.

Comparison of Post-Exercise Recovery and Lung Function in COPD Versus TOPD Patients

Presenter: Sayoni Sengupta.

Distinguishing COPD from tuberculosis-associated obstructive pulmonary disease (TOPD) is important for tailored management. This cross-sectional study compared 74 patients with COPD (n=47) and TOPD (n=27) using radiological assessment, spirometry, and the two chair test (2CT) for post-exercise recovery. The groups were age-matched (66.15±6.95 vs 62.78±9.65 years; p=0.086). TOPD showed greater radiological involvement, with higher Chest X-ray Total Scores (19.8 vs 16.3; p=0.007), while FEV₁, FVC and FEV₁/FVC were similar between groups. FEF25–75% predicted was significantly lower in COPD than TOPD (10.98±5.38 vs 20.57±14.74; p=0.003), indicating greater small airway dysfunction in COPD. Despite similar spirometry, TOPD had greater maximum post-exercise desaturation (4.19±4.45 vs 2.15±1.64; p=0.039). FEV₁ reversibility and post-exercise recovery kinetics did not differ significantly. Overall, TOPD showed greater radiological involvement and post-exercise desaturation, despite less small airway dysfunction than COPD.

Effects of Dual Bronchodilation on Health-Related Quality of Life and Exercise Physiology in Patients with Newly Diagnosed Moderate-to-Severe Chronic Obstructive Pulmonary Disease: A Real-World Study

Presenter: Ieva Dimiene.

Treatment-naïve patients with newly diagnosed COPD have limited real-world evidence regarding the effects of dual bronchodilation on health-related quality of life and exercise physiology. This study assessed 32 treatment-naïve patients with newly diagnosed moderate-to-severe COPD before and after 12 weeks of tiotropium/olodaterol treatment using the Short Form-36 Health Survey (SF-36) and symptom-limited incremental cardiopulmonary exercise test (CPET). SF-36 physical functioning and health change scores improved (p=0.002 and p<0.001, respectively), while other domains remained unchanged. CPET was performed at comparable efforts at both visits. Peak oxygen pulse increased from 74% to 79% pred. (p=0.015), and peak oxygen uptake from 70% to 75% pred. (p=0.044), without a significant change in peak heart rate. Peak minute ventilation to maximal voluntary ventilation ratio VE/MVV decreased from 0.77 to 0.69 (p=0.03). Higher baseline VE/MVV peak predicted a greater reduction after treatment (β=0.77, p<0.001), while beta-blocker use (n=12) did not influence this change (p=0.716). Overall, dual bronchodilation was associated with improved physical functioning and exercise physiology, with greater breathing-reserve gains among patients with greater baseline ventilatory limitation, independent of beta-blocker use.

Efficacy and Safety of Ensifentrine in Chinese Patients with Chronic Obstructive Pulmonary Disease: The ENHANCE-CHINA Randomized Clinical Trial

Presenter: Dr. Fan Wu.

In Chinese patients with moderate-to-severe symptomatic COPD, evidence for ensifentrine has been limited despite prior trials being conducted predominantly in Western populations. The ENHANCE-CHINA trial therefore assessed the efficacy and safety of nebulized ensifentrine versus placebo in a phase III, multicentrere, randomized, double-blind, placebo-controlled study conducted from March 2023 to March 2025. A total of 525 participants were included in the analysis, with 45.9% receiving concomitant maintenance therapy. Ensifentrine significantly improved average FEV1 AUC0-12h versus placebo by 110 ml (95% CI: 69-151; p<0.0001), with consistent lung-function benefits improvement across maintenance-therapy and COPD-severity subgroups. It also significantly improved TDI and showed improvement in ERS and SGRQ. A trend toward fewer moderate-to-severe exacerbations and longer time to first exacerbation was observed, while adverse event rates were similar between groups. Overall, ensifentrine improved lung function, symptoms, and quality of life in this Chinese COPD population. 

Exacerbation-Driven or Eosinophil-Guided? Real-World ICS Decisions in COPD

Presenter: Ethem YILDIZ.

Individualising inhaled corticosteroid (ICS) therapy in COPD according to exacerbation history and blood eosinophil levels remains challenging in routine practice. This retrospective study evaluated 284 stable COPD patients at a tertiary-care university hospital, stratified by eosinophil count as <100, 100–299, or ≥300 cells/µL, with ICS use, GOLD ABE group and exacerbation history assessed. Guideline-discordant ICS use was observed in 162 patients (57.1%), compared with 122 (42.9%) receiving guideline-concordant treatment. Notably, 52 of 90 patients with eosinophils <100 cells/µL continued to receive ICS despite guideline recommendations. Although patients with eosinophils <100 cells/µL were less likely to receive ICS (OR 0.60), eosinophil category was not significantly associated with ICS use (χ²=5.77, p=0.12) or independently predictive of guideline discordance (OR 0.71). In contrast, exacerbation history was the strongest determinant of guideline discordance (OR 1.76). These findings suggest that real-world ICS prescribing was influenced more by exacerbation history than eosinophil-guided recommendations, highlighting a gap in biomarker-based treatment decisions.

Healthcare Resource Utilization (HCRU) in COPD During 52 Weeks of Treatment with Budesonide/Glycopyrronium/Formoterol: Results from the CHOROS ORION Real-World Study in Italy

Presenter: Micaela Romagnoli.

COPD contributes substantially to healthcare resource utilization (HCRU) particularly through emergency and hospital-based care and exacerbation-related events. The CHOROS ORION multicenter, non-interventional, single-arm cohort study examined HCRU among 237 eligible Italian patients with COPD, during 52 weeks following initiation of budesonide/glycopyrronium/formoterol (BGF), compared with the year before treatment. COPD-related ER access decreased from 35 (14.8%) to 13 (5.5%), inpatient hospitalizations from 39 (16.5%) to 25 (10.5%), and day-hospital visits from 4 (1.7%) to 1 (0.4%). Unplanned visits/admissions declined from 35 (81.4%) to 19 (70.4%), whereas planned visits/admissions increased from 5 (11.6%) to 6 (22.2%). Exacerbation-related HCRU decreased from 51 (81.0%) to 10 (30.3%). Median hospitalization duration decreased from 9.0 to 8.5 days, while mean±SD duration decreased from 15.7±25.1 to 11.5±11.1 days. COPD-related GP visits declined from 24 (10.1%) to 8 (3.4%) and specialist outpatient visits from 103 (43.5%) to 45 (19.0%). Overall, HCRU was lower during the 52-week BGF observation period, including reduced acute care utilization, fewer exacerbation-related healthcare encounters, shorter hospital stays, and lower outpatient healthcare use.

Impact of Single-Inhaler Triple Therapy FF/UMEC/VI on Disease Stability in COPD: A Real-World 12-Month Analysis

Presenter: MD Corrado Pelaia.

Persistent symptoms and exacerbations despite dual bronchodilation can complicate disease stability in COPD, with real-world evidence on multidimensional outcomes remaining limited. This retrospective single-center study assessed 86 adults with COPD treated with once-daily fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) 92/55/22 ug over 12 months. Spirometry, lung volumes, DLCO, CAT scores, and moderate/severe exacerbations were evaluated before and after treatment. At 12 months, FEV1 increased from 1.46 to 1.61 L (p<0.01), FEV1/FVC from 0.65 to 0.69 (p<0.001), and FEF25-75 from 0.84 to 0.99 L/s (p<0.001). RV decreased from 2.90 to 2.50 L (p<0.0001), while DLCO increased from 4.59 to 4.86 (p<0.05). CAT scores improved from 26.0 to 22.9 (p<0.0001), and exacerbations declined from 1.08 to 0.15. Overall, 72% achieved composite stability encompassing symptoms, function, and absence of events. Higher baseline RV% and TLC% predicted lower stability, whereas higher DLCO% predicted greater stability. The findings indicate improvements across physiological, symptomatic, and exacerbation outcomes during FF/UMEC/VI treatment in this real-world cohort.

Late Breaking Abstract - Eosinophil Guided Therapy for Severe COPD – A Randomised Controlled Trial for Inhaled Corti-Costeroid Treatment (The COPERNICOS Trial)

Presenter: Anna Kubel Vognsen.

The potential adverse effects of inhaled corticosteroids (ICS) make strategies to reduce exposure relevant in severe COPD, although the safety of eosinophil-guided treatment remains uncertain. The COPERNICOS trial was a 1-year, nationwide, multicentre, open-label, randomised controlled non-inferiority trial involving 444 patients with GOLD E COPD, randomised 1:1 to eosinophil-guided therapy (EGT) or continued triple therapy. EGT used a “switch on – switch off” approach updated every three months. Severe exacerbations or all-cause mortality did not differ significantly between groups (incidence rate ratio 1·06, CI 0·69-1·62, p=0·77; 210 versus 176 events), although formal non-inferiority was not demonstrated. Daily budesonide-equivalent ICS exposure was reduced by 28%, from 696µg (CI 696-800) with continued triple therapy to 502µg (CI 35µg-692µg) with EGT (p<0·001). Systemic steroid use was similar (0·51 mg versus 0·51 mg, p=0·50), as was pneumonia risk. Thus, eosinophil-guided therapy reduced cumulative ICS exposure without a significant increase in severe exacerbations or mortality, although the non-inferiority criterion was not formally met.

Modelling Predictive Characteristics for Disease Stability in COPD: IMPACT Post Hoc Analysis

Presenter: Prof. Dave Singh.

Evidence supporting very-low-dose inhaled corticosteroid/long-acting β₂-agonist (ICS/LABA) Maintenance and Reliever Therapy (MART) in children aged 6–11 years requiring Step 3 treatment remains limited. This open-label, non-inferiority randomized controlled trial evaluated very-low-dose MART versus fixed-low-dose ICS/LABA plus as-needed SABA in newly diagnosed children aged 6–11 years requiring Step 3 therapy according to GINA guidelines. Of 98 randomized children, 94 (47 in each group) completed 3 months of follow-up; mean (SD) age was 8 (1.6) years and 71 (72.5%) were male. Change in ACQ-5 scores was similar with MART and fixed-dose ICS/LABA [1.61 (0.99) vs 1.59 (0.89); p=0.89]. The between-group mean difference was 0.02 [95% CI (-0.37 to 0.42)], remaining within the prespecified non-inferiority limit of 0.5. No significant differences were observed in FEV1 change, exacerbations, OCS use, emergency visits, or hospitalizations. Very-low-dose MART was therefore non-inferior to fixed-low-dose ICS/LABA plus as-needed SABA over 3 months.

Moderate-To-Severe Exacerbation Risk Among Patients with COPD who had One Recent Exacerbation: A Post-Hoc Analyses of the ETHOS and KRONOS Studies

Presenter: Mehul Patel.

A single recent exacerbation in COPD patients (EOS 100 to ≥300 cells/mm³) is now relevant to treatment escalation under GOLD 2026, making the comparative risk of subsequent exacerbations with triple versus dual therapy clinically important. This post-hoc analysis of the 52-week ETHOS (N=8572) and 24-week KRONOS (N=1902) phase 3 studies assessed moderate-to-severe exacerbation risk in patients with moderate-to-very severe COPD who had experienced one moderate/severe exacerbation during the year before baseline. In ETHOS, BGF 320/14.4/10 µg reduced exacerbation risk compared with GFF 14.4/10 µg (RR 0.80 [95% CI 0.69–0.92]) and BFF 320/10 µg (RR 0.83 [95% CI 0.72–0.96]). In KRONOS, BGF 320/14.4/10 µg similarly reduced exacerbation risk versus BUD/FORM 400/12 µg (RR 0.44 [95% CI 0.22–0.88]), GFF 14.4/10 µg (RR 0.33 [95% CI 0.18–0.60]), and BFF 320/10 µg (RR 0.42 [95% CI 0.21–0.84]). Overall, these findings indicate that BGF may be associated with a lower moderate-to-severe exacerbation risk than LAMA/LABA or ICS/LABA therapy in patients with moderate-to-severe COPD following a single recent exacerbation, supporting the treatment considerations outlined in GOLD 2026.

Patterns of Comorbidities in People with COPD – Secondary Analyses of Baseline Data from A Clinical Trial

Presenter: Dr. Sameera Ansari.

Comorbidities frequently coexist with COPD and can contribute to greater symptom burden and poorer health outcomes, making recognition of multimorbidity patterns relevant to integrated care. This secondary analysis of baseline data from the APCOM randomised controlled trial examined comorbidity patterns derived through clustering analyses and their associations with demographic characteristics and health outcomes in 220 people with COPD. Overall, 132 distinct comorbidities were reported, with hypertension (54.5%), lipid disorders (42.7%), and gastro-oesophageal reflux disease (35.0%) being most prevalent. Three multimorbidity patterns emerged: older patients with predominantly cardiometabolic conditions, patients with depression and mixed comorbidities, and patients with a low comorbidity burden. The depression-associated cluster had the highest symptom burden, greatest pain/discomfort and anxiety/depression, and more severe COPD exacerbations. Increasing age was associated with lower smoking prevalence and less pain/discomfort and anxiety/depression. These findings indicate distinct multimorbidity profiles in COPD, with the depression-dominant pattern associated with poorer symptom and patient-reported outcomes, highlighting the relevance of mental health assessment within integrated COPD management.

Predictive Biomarkers for Triple Therapy Response in COPD: A Randomised Controlled Trial

Presenter: Koichiro Takahashi.

Evidence for the clinical benefit of ICS/LAMA/LABA triple therapy (TT) in mild-to-moderate COPD remains limited. This multicentre randomised controlled trial explored biomarkers that may predict response to TT in symptomatic COPD patients with CAT ≥7 and postbronchodilator FEV₁ >50% predicted from 44 hospitals in Japan. A total of 572 patients were randomised to TT with FF/UMEC/VI (n=279) or (DT) dual therapy with UMEC/VI (n=278) for 24 weeks. At 12 weeks, patients with blood eosinophil counts (BEC) ≥300 cells/μL had greater FEV₁ improvement with TT than DT (178 vs 105 mL; p<0.05). BEC showed a positive dose-response association with FEV₁ improvement on TT (β=+9.8 mL), contrasting with DT (β=−15.0 mL; p=0.01). YKL-40 showed opposite treatment slopes (TT β=+4.7; DT β=−3.7; p=0.49), while CCL18 showed a borderline negative association with TT (β=−47.1; p=0.087); periostin and DPP-4 showed no meaningful associations. A biomarker strategy combining BEC with YKL-40 and CCL18 may help stratify triple-therapy benefit in mild-to-moderate COPD, supporting a more personalised treatment approach.

Predictors of the Effectiveness of Nebulized NAC in Patients with Stable COPD

Presenter: Dmytro Dobrianskyi.

Persistent productive cough with viscous sputum is a common feature of stable COPD, for which current clinical guidelines recommend add-on mucolytic therapy. This study evaluated predictors of response to short-term nebulized N-acetylcysteine (NAC) in 34 patients with spirometry-confirmed COPD of at least 12 months' duration and persistent productive cough. Patients received nebulized NAC 300 mg twice daily (600 mg/day) for 10 days. Clinical status was assessed before and after treatment using the CAT, CCQ, SGRQ, mMRC, daytime and nighttime cough questionnaires, 6-minute walk test, FEV₁, and sputum leukocyte count. Treatment was associated with significant reductions in CAT (12.3%), CCQ (7.9%), daytime cough (15.0%), and nighttime cough (31.3%) scores, alongside improved FEV₁, while other measures showed no significant change. Responders, defined by a ≥3-point reduction in CAT score, were distinguished by baseline daytime cough severity, which was the only independent predictor of treatment response (OR 3.08; 95% CI 1.04–9.15; p=0.04), with a threshold score of 3.00 (sensitivity 62%; specificity 73%). These findings suggest that patients with stable COPD who have more severe daytime cough and viscous sputum may derive greater symptomatic benefit from short-term add-on nebulized NAC therapy.

Role of Oscillometry and Therapeutic Response to Fluticasone/Vilanterol in Pre COPD: A Randomized, Double Blind, Placebo Controlled Trial

Presenter: Milind Sovani.

Pre-COPD can present with COPD symptoms and relevant exposures despite normal spirometry, creating a potential role for more sensitive measures of small airway dysfunction. This 12-week, double-blind, placebo-controlled RCT across 10 Indian centres enrolled adults aged 35–55 years with CAT >10, >10 pack-years of smoking or equivalent biomass exposure, normal spirometry (FEV₁ >80% predicted and FEV₁/FVC >0.7), and oscillometry-defined AX >6 cmH₂O/L.s. Of 149 screened individuals, 93 were randomised to once-daily fluticasone/vilanterol (FF/V; n=43) or placebo (n=50), with 67 participants available for analysis (FF/V 32; placebo 35). FF/V produced greater improvement in CAT score than placebo (−9.16 vs −6.69; difference 2.46, p=0.048) and AX (−3.02 vs −0.13; p<0.05). No changes occurred in spirometry or R5–R20. HRCT identified emphysema (<−950 HU) in 26.6% of participants. The findings suggest that oscillometry-defined pre-COPD may identify individuals demonstrating symptomatic and AX responses to FF/V despite preserved spirometry.

The Role of OPEP in Patients with COPD: A Non-Pharmacological Interventional Study

Presenter: Juliano Colapelle.

Management of the chronic bronchitis phenotype in COPD remains challenging because pharmacological options can have substantial side effects and variable efficacy, prompting interest in non-pharmacological approaches. This ongoing clinical trial (NCT06614959) evaluated home use of an oscillatory positive expiratory pressure (OPEP) device (Aerobika Arx) for ≥2 daily sessions over 4 consecutive weeks in patients with COPD and chronic bronchitis. CASA-Q, CAT, and spectral/intra-breath oscillometry were assessed at baseline and study completion, with Cough Impact (COUI) and reactance at 5 Hz (X5) as co-primary outcomes. Among 18 participants (mean age 68.82 ± 8.8 years; 33% female; FEV₁ 38.72 ± 14.3% predicted), COUI improved from 67.88 ± 21.4 to 75.35 ± 14.4 (p<0.05), while X5 improved from −4.42 [−5.0, −3.6] to −4.24 [−5.3, −3.2] cmH₂O/L/s (p<0.001). Total CASA-Q also improved (61.94 ± 18.3 to 70.35 ± 12.8; p<0.05), alongside changes in airway resistance/reactance. OPEP therapy was associated with improved symptom burden and airway mechanics in this COPD population.

Within-Breath Respiratory Oscillometry to Differentiate between Asthma and COPD

Presenter: Lauren G. Reinders.

Clinical overlap between asthma and COPD can make disease differentiation challenging, while differences in within-breath respiratory mechanics may provide additional discriminatory information. This study assessed whether within-breath respiratory oscillometry could distinguish between confirmed asthma and COPD. Forty-nine patients with asthma and 52 with COPD underwent respiratory oscillometry using the Tremoflo C-100, followed by spirometry. Two logistic regression models combined within-breath oscillometry parameters with clinical variables: the first used flow-independent resistance and reactance measures at 5 Hz, specifically end-expiratory and end-inspiratory parameters, while the second incorporated flow-dependent expiratory and inspiratory within-breath parameters. The first model achieved an AUC of 0.86 (95% CI 0.79–0.94). The flow-dependent model performed better, with a Nagelkerke R² of 0.692 and an AUC of 0.94 (95% CI 0.89–0.99). After internal validation, the AUC remained 0.92, with sensitivity of 0.92 (95% CI 0.82–0.98) and specificity of 0.90 (95% CI 0.83–0.92). These findings support the discriminative potential of flow-dependent within-breath expiratory and inspiratory respiratory oscillometry parameters for differentiating asthma from COPD.

ERS Congress 2026, 5-9 September, Barcelona, Spain