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Updated: Jan 22, 2026

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Published on: March 18, 2019
Pragmatic evaluation of inhaled corticosteroid particle size formulations on asthma control
Chris RuiWen Kuo1, Sunny Jabbal1, William Anderson1
1Scottish Centre for Respiratory Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK.
Background:
Extra-fine particle formulations of inhaled corticosteroid (ICS) are associated with improved lung delivery.
Objectives:
A pragmatic study to assess patient-reported outcomes after switching from fine to extra-fine particle ICS in persistent asthma.
Methods:
Twenty-four patients (mean age 48 year, FEV1 84%, ACQ 1.67) received 4 weeks run-in with a constant dose of fine particle ICS (mean dose 710 µg), followed by switching to an equivalent dose of extra-fine particle hydrofluoroalkane beclomethasone dipropionate (mean dose 355µg). Asthma control questionnaire (ACQ), the primary outcome and mini asthma quality of life questionnaire (mAQLQ) were measured pre- and post-run-in (baseline) and after 4 weeks and 8 weeks of switching.
Results:
Comparing pre- vs post-run-in, there were no differences for ACQ: 1.67 vs 1.65 or AQLQ: 5.08 vs 5.34. There were mean (95%CI) improvements (P < 0.001) from baseline after 8 weeks for ACQ: -0.53 (-0.83, -0.23) and AQLQ: 0.69 (0.35, 1.04), which exceeded the minimal clinically important difference (MCID) of 0.5 for both. There were also differences (P < 0.05) in domiciliary symptoms and reliever use. There were no significant changes at 8 weeks in lung function, FeNO or blood eosinophils.
Conclusions:
Pragmatic switching from fine to extra-fine particle ICS at half the dose was associated with clinically relevant improvements in asthma control and quality of life, but not lung function or type 2 biomarkers.
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