AsthmaAM-IOSNCT06425562
The Potential Added Value of Impulse Oscillometry in Asthma Monitoring
A study testing Full lung function, Multiple breath nitrogen washout and Impulse oscillometry in people with Asthma, run by Universitair Ziekenhuis Brussel at 1 site in Belgium.
Trial summary
The goal of this longitudinal observational study is to learn if impulse oscillometry (IOS) has an added value in asthma monitoring in adult asthma patients who are prescribed a change in asthma maintenance therapy. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Asthma
- What is being tested?
- Full lung function, Multiple breath nitrogen washout and Impulse oscillometry
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 1 siteBelgium
- Study dates
- 1 Sep 2024to Apr 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adult asthma patients with a scheduled consultation at the outpatient hospital to whom a step-up or step-down of their pharmacological asthma treatment is prescribed
Who cannot join
- Unstable asthma (defined as need for oral corticosteroids or (respiratory) antibiotic course in the 4 weeks before inclusion or any major medical issue in the 4 weeks before inclusion)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
Universitair Ziekenhuis Brussel
Brussels, 1090
About this study
The goal of this longitudinal observational study is to learn if impulse oscillometry (IOS) has an added value in asthma monitoring in adult asthma patients who are prescribed a change in asthma maintenance therapy. The main questions it aims to answer are:
- Is there a difference in the change in IOS parameters and FEV1 respectively, stratified according to change in asthma control test?
- Is there a difference in the change in IOS parameters and FEV1 respectively, stratified according to change in other questionnaire such as the asthma control questionnaire and the asthma quality of life questionnaire.
- Are the proposed minimal clinically important differences (MCIDs) valid for short follow-up periods (3 - 6 months)?
Participants will undergo lung function testing (full lung function, multiple breath nitrogen washout, impulse oscillometry) and questionnaires (asthma control test, asthma control questionnaire, asthma quality of life questionnaire), once during the baseline visit and once during the follow-up visit three to six months later.
- Conditions
- Asthma
- Being tested
- Full lung function, Multiple breath nitrogen washout, Impulse oscillometry
- Keywords
- impulse oscillometry, asthma monitoring
- Medical subject headings
- Asthma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Full lung functionOther
This includes spirometry, body plethysmography and single breath gas transfer test. These are all non-invasive physiological measurements / lung function tests. Measures flow volumes, lung volumes and gas transfer respectively.
Multiple breath nitrogen washoutOther
Non-invasive physiological measurement / lung function test. 100% oxygen is inhaled and the nitrogen concentration in the lungs is measured. This test gives information on the ventilation distribution in the lungs.
Impulse oscillometryOther
Non-invasive physiological measurement / lung function test. This technique superimposes sound waves on tidal breathing. The patient can breathe normally trough the device, no forced respiratory maneuvers are required. It gives information on the reactance and resistance of the lung.
| Study group | Role | What they receive |
|---|---|---|
| Adult asthma patients | Experimental | Lung function tests (full lung function, multiple breath nitrogen washout, impulse oscillometry) and questionaires (asthma control test, asthma control questionnaire, asthma quality of life questionnaire) will be conducted, once at baseline and once 3 - 6 months later during follow-up. Receives: Other: Full lung function; Other: Multiple breath nitrogen washout; Other: Impulse oscillometry |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in frequency dependance of resistance (FDR) stratified according to change in asthma control test (ACT)
Frequency dependance of resistance (FDR) is an impulse oscillometry parameter. FDR is expressed in kPa/(L.s). A lower FDR indicates a clinically better outcome. The ACT is a questionnaire which consists of 5 questions, each evaluated on a 5-point Likert-Scale. Total score ranges between 5 and 25, where a lower score is clinically worse than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in area of reactance (AX) stratified according to change in asthma control test (ACT)
Area of reactance (AX) is an impulse oscillometry parameter. AX is expressed in kPa/L. A lower AX indicates a clinically better outcome. The ACT is a questionnaire which consists of 5 questions, each evaluated on a 5-point Likert-Scale. Total score ranges between 5 and 25, where a lower score is clinically worse than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in forced expiratory volume in 1 second (FEV1) stratified according to change in asthma control test (ACT)
Spirometry parameter: forced expiratory volume in 1 second (FEV1). FEV1 is expressed in L. A higher FEV1 indicates a clinically better outcome. The ACT is a questionnaire which consists of 5 questions, each evaluated on a 5-point Likert-Scale. Total score ranges between 5 and 25, where a lower score is clinically worse than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Secondary outcomes (8)
Change in frequency dependence of resistance (FDR) stratified according to change in asthma control questionnaire (ACQ-6)
Frequency dependance of resistance (FDR) is an impulse oscillometry parameter. FDR is expressed in kPa/(L.s). A lower FDR indicates a clinically better outcome. The ACQ-6 is a questionnaire which consists of 6 questions, each evaluated on a 7-point Likert-Scale. The total score score is divided by 6 yielding a mean score ranging from 0.0 to 6.0, where a lower score is clinically better than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in area of reactance (AX) stratified according to change in asthma control questionnaire (ACQ-6)
Area of reactance (AX) is an impulse oscillometry parameter. AX is expressed in kPa/L. A lower AX indicates a clinically better outcome. The ACQ-6 is a questionnaire which consists of 6 questions, each evaluated on a 7-point Likert-Scale. The total score score is divided by 6 yielding a mean score ranging from 0.0 to 6.0, where a lower score is clinically better than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in forced expiratory volume in 1 second (FEV1) stratified according to change in asthma control questionnaire (ACQ-6)
Spirometry parameter: forced expiratory volume in 1 second (FEV1). FEV1 is expressed in L. A higher FEV1 indicates a clinically better outcome. The ACQ-6 is a questionnaire which consists of 6 questions, each evaluated on a 7-point Likert-Scale. The total score score is divided by 6 yielding a mean score ranging from 0.0 to 6.0, where a lower score is clinically better than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in frequency dependence of resistance (FDR) stratified according to change in asthma quality of life questionnaire (AQLQ)
Frequency dependance of resistance (FDR) is an impulse oscillometry parameter. FDR is expressed in kPa/(L.s). A lower FDR indicates a clinically better outcome. The AQLQ is a questionnaire which consists of 32 questions, each evaluated on a 7-point Likert-Scale. The total score is divided by 32 yielding a mean score ranging from 1.0 to 7.0, where a lower score is clinically worse than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in area of reactance (AX) stratified according to change in asthma quality of life questionnaire (AQLQ)
Area of reactance (AX) is an impulse oscillometry parameter. AX is expressed in kPa/L. A lower AX indicates a clinically better outcome.The AQLQ is a questionnaire which consists of 32 questions, each evaluated on a 7-point Likert-Scale. The total score is divided by 32 yielding a mean score ranging from 1.0 to 7.0, where a lower score is clinically worse than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in forced expiratory volume in 1 second (FEV1) stratified according to change in asthma quality of life questionnaire (AQLQ)
Spirometry parameter: forced expiratory volume in 1 second (FEV1). FEV1 is expressed in L. A higher FEV1 indicates a clinically better outcome.The AQLQ is a questionnaire which consists of 32 questions, each evaluated on a 7-point Likert-Scale. The total score is divided by 32 yielding a mean score ranging from 1.0 to 7.0, where a lower score is clinically worse than a higher score.
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in frequency dependence of resistance (FDR) over the 3-6 months observation period compared to proposed minimal clinically important differences (MCIDs) (calculated for a one year interval) for FDR.
MCIDs over 1 year have been published for IOS parameters. For frequency dependence of resistance (FDR) the MCID is defined as a decline of FDR greater or equal to 0.06 kPa/(L.s). Change of FDR ≥ 0.06 kPa/(L.s) or not
Measured: Once at baseline and 3 - 6 months later during follow-up
Change in area of reactance (AX) over the 3-6 months observation period compared to proposed minimal clinically important differences (MCIDs) (calculated for a one year interval) for AX.
MCIDs over 1 year have been published for IOS parameters. For area of reactance (AX) the MCID is defined as a decline of AX greater or equal to 0.65 kPa/L. Change of AX ≥ 0.65 kPa/L or not
Measured: Once at baseline and 3 - 6 months later during follow-up
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 May 2024
- Study start1 Sep 2024
- Primary completionApr 2026 (estimated)
- Study completionApr 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AsthmaStudies of the same condition, open and under way.
- More trials run by Universitair Ziekenhuis BrusselThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universitair Ziekenhuis Brussel
- Sponsor type
- University, hospital or other
- Collaborators
- Vrije Universiteit Brussel
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06425562
- Sponsor's protocol ID
- 24151_AM-IOS
- Acronym
- AM-IOS
- Status last verified
- Sep 2025
- First submitted
- 30 Apr 2024
- Last updated
- 15 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Potential Added Value of Impulse Oscillometry in Asthma Monitoring
- ClinicalTrials.gov ID
- NCT06425562
- Acronym / sponsor ID
- AM-IOS / 24151_AM-IOS
- Conditions
- Asthma
- Keywords
- impulse oscillometry, asthma monitoring
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Universitair Ziekenhuis BrusselUniversity, hospital or other
- Collaborators
- Vrije Universiteit Brussel
- Study start
- 1 Sep 2024 (actual)
- Primary completion
- Apr 2026 (estimated)
- Study completion
- Apr 2026 (estimated)
- First posted
- 22 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this longitudinal observational study is to learn if impulse oscillometry (IOS) has an added value in asthma monitoring in adult asthma patients who are prescribed a change in asthma maintenance therapy. The main questions it aims to answer are:
- Is there a difference in the change in IOS parameters and FEV1 respectively, stratified according to change in asthma control test?
- Is there a difference in the change in IOS parameters and FEV1 respectively, stratified according to change in other questionnaire such as the asthma control questionnaire and the asthma quality of life questionnaire.
- Are the proposed minimal clinically important differences (MCIDs) valid for short follow-up periods (3 - 6 months)?
Participants will undergo lung function testing (full lung function, multiple breath nitrogen washout, impulse oscillometry) and questionnaires (asthma control test, asthma control questionnaire, asthma quality of life questionnaire), once during the baseline visit and once during the follow-up visit three to six months later.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adult asthma patients | Experimental | Other: Full lung function, Other: Multiple breath nitrogen washout, Other: Impulse oscillometryLung function tests (full lung function, multiple breath nitrogen washout, impulse oscillometry) and questionaires (asthma control test, asthma control questionnaire, asthma quality of life questionnaire) will be conducted, once at baseline and once 3 - 6 months later during follow-up. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Adult asthma patients with a scheduled consultation at the outpatient hospital to whom a step-up or step-down of their pharmacological asthma treatment is prescribed
Key exclusion criteria (1 listed)
- Unstable asthma (defined as need for oral corticosteroids or (respiratory) antibiotic course in the 4 weeks before inclusion or any major medical issue in the 4 weeks before inclusion)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Full lung functionThis includes spirometry, body plethysmography and single breath gas transfer test. These are all non-invasive physiological measurements / lung function tests. Measures flow volumes, lung volumes and gas transfer respectively. | Other | Adult asthma patients |
| Multiple breath nitrogen washoutNon-invasive physiological measurement / lung function test. 100% oxygen is inhaled and the nitrogen concentration in the lungs is measured. This test gives information on the ventilation distribution in the lungs. | Other | Adult asthma patients |
| Impulse oscillometryNon-invasive physiological measurement / lung function test. This technique superimposes sound waves on tidal breathing. The patient can breathe normally trough the device, no forced respiratory maneuvers are required. It gives information on the reactance and resistance of the lung. | Other | Adult asthma patients |
Primary outcome
Change in frequency dependance of resistance (FDR) stratified according to change in asthma control test (ACT)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Frequency dependance of resistance (FDR) is an impulse oscillometry parameter. FDR is expressed in kPa/(L.s). A lower FDR indicates a clinically better outcome. The ACT is a questionnaire which consists of 5 questions, each evaluated on a 5-point Likert-Scale. Total score ranges between 5 and 25, where a lower score is clinically worse than a higher score.
Change in area of reactance (AX) stratified according to change in asthma control test (ACT)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Area of reactance (AX) is an impulse oscillometry parameter. AX is expressed in kPa/L. A lower AX indicates a clinically better outcome. The ACT is a questionnaire which consists of 5 questions, each evaluated on a 5-point Likert-Scale. Total score ranges between 5 and 25, where a lower score is clinically worse than a higher score.
Change in forced expiratory volume in 1 second (FEV1) stratified according to change in asthma control test (ACT)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Spirometry parameter: forced expiratory volume in 1 second (FEV1). FEV1 is expressed in L. A higher FEV1 indicates a clinically better outcome. The ACT is a questionnaire which consists of 5 questions, each evaluated on a 5-point Likert-Scale. Total score ranges between 5 and 25, where a lower score is clinically worse than a higher score.
8 secondary outcomes
Change in frequency dependence of resistance (FDR) stratified according to change in asthma control questionnaire (ACQ-6)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Change in area of reactance (AX) stratified according to change in asthma control questionnaire (ACQ-6)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Change in forced expiratory volume in 1 second (FEV1) stratified according to change in asthma control questionnaire (ACQ-6)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Change in frequency dependence of resistance (FDR) stratified according to change in asthma quality of life questionnaire (AQLQ)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Change in area of reactance (AX) stratified according to change in asthma quality of life questionnaire (AQLQ)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Change in forced expiratory volume in 1 second (FEV1) stratified according to change in asthma quality of life questionnaire (AQLQ)
Time frame: Once at baseline and 3 - 6 months later during follow-up
Change in frequency dependence of resistance (FDR) over the 3-6 months observation period compared to proposed minimal clinically important differences (MCIDs) (calculated for a one year interval) for FDR.
Time frame: Once at baseline and 3 - 6 months later during follow-up
Change in area of reactance (AX) over the 3-6 months observation period compared to proposed minimal clinically important differences (MCIDs) (calculated for a one year interval) for AX.
Time frame: Once at baseline and 3 - 6 months later during follow-up
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Full lung function, Multiple breath nitrogen washout and Impulse oscillometry in people with Asthma, run by Universitair Ziekenhuis Brussel at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Shane Hanon, Prof. Dr. MD. (02 477 6841, Shane.Hanon@uzbrussel.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in frequency dependance of resistance (FDR) stratified according to change in asthma control test (ACT) (time frame: Once at baseline and 3 - 6 months later during follow-up). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Sep 2025.