NCT07364188Not yet recruiting
Bronchodilator Response in COPD and Asthma: Correlation Between Spirometry, IOS Indices, and Dyspnea Relief
Source: ClinicalTrials.gov · Last updated 26 Jan 2026
Brief summary (registry, in English)
A bronchodilator reversibility test is widely used in the diagnosis and management of obstructive lung diseases. Bronchodilators relieve symptoms in asthma and COPD. Traditionally, their effectiveness has been assessed using spirometric indices, particularly FEV₁. However, changes in FEV₁ often do not correlate well with patients' subjective experience of dyspnoea relief or with changes in small airway function. Impulse oscillometry (IOS) provides an effort-independent assessment of respiratory mechanics during tidal breathing and is more sensitive to small airway dysfunction than spirometry. Despite this, the clinical utility of IOS in routine COPD and asthma assessment remains underexplored, and its relationship to both spirometric response and symptom relief is not fully established, and the Minimal Clinically Important Difference (MCID) for IOS parameters has not been firmly established. Determining the MCID is essential for interpreting individual patient responses in a clinically meaningful way and for guiding treatment decisions in both research and practice. Hypothesis \& Aims In patients with either asthma or COPD baseline values and bronchodilator responses are compared. More specifically, this study aims to: 1. assess baseline correlations: Evaluate the correlation between ΔX5-baseline (EFL expiratory flow limitation=small airway collapse during expiration), RV/TLC-baseline, X5-average at baseline, FEV1-baseline, VAS-dyspnea at baseline, and ACQ-6-baseline. 2. compare bronchodilator responses across methods: Examine the correlation between bronchodilator-induced changes in FEV₁ and IOS parameters (including both average and delta values) and explore their relationship with short-term changes in dyspnea. 3. establish clinical relevance: Determine the MCID for key IOS variables using both anchor-based and distribution-based approaches, anchored to perceived changes in lung symptoms.
- Status (registry)
- Not yet recruiting
- Study type
- Observational
- Enrollment
- 120 (estimated)
- First submitted
- 16 Jan 2026
- Start date
- 1 Feb 2026
- Primary completion date
- 31 Dec 2027
- Lead sponsor
- Allergi- og Lungeklinikken, Elsinore
- NCT number
- NCT07364188
What you commit to
- Study type: Observational
- Planned participants: 120
- From 1 Feb 2026 to the primary completion date, 31 Dec 2027
- No sites listed in no country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Other illness
- Cognitive disorders and not able to answer Asthma Control Questionnaire (ACQ), VAS dyspnea score, and COPD Assessment Test (CAT) score (25-28).
- Comorbidities with significant influence on dyspnea eg. bronchiectasis, ILS, mb. Cordis, lung resection, anemia, and active malignant disease
Age
- Patients aged less than 18 years old.
Other
- Not able to perform spirometry or impulse oscillometry.
- Short-acting beta-agonists 6 h, long-acting beta-agonists 2 days, short-acting anti-muscarinic agent 12 h, Long-acting anti-muscarinic agents 2 days.
- BMI ≥40 kg/m2.
Who the study is looking for
- Both asthma and COPD patients:
- Written informed consent.
- FEV1/Forced Vital Capacity (FVC) \<0.7 at baseline (7)
- Visual Analog Scale (VAS) dyspnea score ≥10 (0-100, 100 max) (25,26).
- Asthma: Doctor diagnosed asthma
- 1\. less than 10 packyears.
- COPD: Doctor diagnosed COPD with FEV1/FVC \<0.7 post-bronchodilation 1. Smokers or ex-smokers with ≥10 packyears
Age in the registry: 18 years to - · Sex: All · Does not accept healthy volunteers
This page is information, not medical advice. Discuss any trial with your doctor.