The Potential Added Value of Impulse Oscillometry in Asthma Monitoring

Conditions studied

Asthma

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.

Interventions

• Other: Full lung function — 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.
• Other: Multiple breath nitrogen washout — 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.
• Other: Impulse oscillometry — 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.

Primary outcomes

• Change in frequency dependance of resistance (FDR) stratified according to change in asthma control test (ACT) (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) (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) (Once at baseline and 3 - 6 months later during follow-up)

Eligibility information

Study locations

• Universitair Ziekenhuis Brussel, Brussels, 1090 Belgium