Nocturnal temperature controlled laminar airflow for treating atopic asthma: a randomised controlled trial.

Objective: To determine whether environmental control using nocturnal temperature controlled laminar airflow (TLA) treatment could improve the quality of life of patients with persistent atopic asthma.

Design: Randomised, double-blind, placebo-controlled, parallel-group trial. Setting Nineteen European asthma clinics.

Participants: 312 patients aged 7-70 with inadequately controlled persistent atopic asthma.

Main Outcome Measure: Proportion of patients with an increase of ≥0.5 points in asthma quality of life score after 1 year of treatment.

Results: TLA devices were successfully installed in the bedrooms of 282 (90%) patients included in the primary efficacy analysis. There was a difference in treatment response rate between active (143 of 189, 76%) and placebo (56 of 92, 61%) groups, difference 14.8% (95% CI 3.1 to 26.5, p=0.02).3 In patients aged ≥12, on whom the study was powered, the difference in response rate was similar-active 106 of 143 (74%), placebo 42 of 70 (60%), difference 14.1% (0.6 to 27.7, p=0.059). There was a difference between groups in fractional exhaled nitric oxide change of -7.1 ppb (-13.6 to -0.7, p=0.03). Active treatment was associated with less increase in cat-specific IgE than placebo. There was no difference in adverse event rates between treatment groups.

Conclusion: Inhalant exposure reduction with TLA improves quality of life, airway inflammation and systemic allergy in patients with persistent atopic asthma. TLA may be a treatment option for patients with inadequately controlled persistent atopic asthma. Trial registration number Clinical Trials NCT00986323.