Severe asthma exacerbations are costly to patients and the NHS and occur frequently in patients
with severe allergic asthma.
To ascertain whether the use of a temperature-controlled laminar airflow (TLA) device (Airsonett®) over a 12-month period can reduce the frequency of severe exacerbations and improve asthma control and quality of life as compared to a placebo device in adults with severe allergic asthma.
A mixed methods, multi-centre, randomised, double-blind, placebo-controlled, parallel group, trial design.
Adults (16-75 years) with severe, poorly-controlled, exacerbation-prone, asthma sensitised to a perennial indoor aeroallergen.
Main Outcome Measures
Frequency of severe asthma exacerbations occurring within the 12-month follow-up period, defined as worsening of asthma requiring systemic corticosteroids, ≥30mg prednisolone or equivalent daily (or ≥50% increase in dose if maintenance 30mg prednisolone or above) for 3 or more days.
Changes in asthma control, lung function, asthma-specific and global quality of life for participants and device acceptability.
240 participants were randomised. 119 Active Treatment : 121 Placebo. 202 participants (84%) reported use of the device for 9-12 months. Qualitative analyses showed high levels of acceptability. The mean rate of severe exacerbations did not differ between groups (Active: Mean 1.39 (SD 1.57), Placebo: Mean 1.48 (SD 2.03) Risk Ratio 0.92, 95% CI 0.66-1.27, p=0.616). There were no significant differences in secondary outcomes for lung function, except for a reduction in mean daily peak expiratory flow (difference 14.7 L/min, SD 7.35, 95% CI 0.32-29.1 L/min, p=0.045) in the active device, and no differences in asthma control or airway inflammation. There was no difference in generic or disease-specific health-related quality of life overall, although statistically significant higher quality of life at month 6 was observed.
Within the limits of the data, no consistent benefits of the active device were demonstrated.
|Date of Award||Sept 2018|
|Supervisor||Anoop Chauhan (Supervisor), Rebecca Stores (Supervisor), Karen Pilkington (Supervisor) & Ann Dewey (Supervisor)|