Use of the temperature-controlled Laminar Airflow (Airsonett AB) device at night was associated with an improved score on the Asthma Quality of Life Questionnaire (AQLQ) in ≤3 months, according to a study published in Respiratory Medicine. Sleep quality-related answers within 1 month from the start of treatment appear to indicate treatment response.

This was a post-hoc analysis of a phase 3 double-blind, placebo-controlled parallel-group study that included 282 individuals aged 7 to 70 years with either a temperature-controlled Laminar Airflow device or placebo in their bedroom for 1 year. The AQLQ was administered to all participants. Time to onset of improvements for both AQLQ and the Asthma Control Test (ACT) was measured in all participants and in 3 designated subgroups. These included ACT<18, Global Initiative for Asthma (GINA)=4, and ACT<18 + GINA=4). Time to onset of improvements for temperature-controlled Laminar Airflow vs placebo was calculated using area-under-curve subtractive analysis from 12 months down to 1 month in 3-month increments for AQLQ score, its 4 domains, and the question pertaining to sleep.

Of the study population, 87 with acute, uncontrolled asthma on GINA step 4 showed 3-month improvement ≥0.5 points on AQLQ (0.57; P =.009) for temperature-controlled Laminar Airflow vs placebo. The minimum times to onset of improvements (within 1 month) were in the domains of environmental (0.68; P =.016) and sleep (0.771; P =.037) questions. Time to onset was 3 months for the emotional domain (0.66; P =.020) and the symptom domain (0.64; P =.014) and was 6 months for the activity domain (0.47; P =.036). Time to onset of improvements was statistically significant in all participants in the environment (0.309; P =.029) and symptoms domains (0.255; P =.039) at 9 months.

Limitations to this analysis included a post-hoc design, conservative approaches to individual tests, and missing data.

The researchers concluded that “nocturnal avoidance of allergens using [temperature-controlled Laminar Airflow] provides a clinically relevant improvement in total AQLQ score within 3 months in patients in the GINA 4 + ACT <18 group. Questions related to sleep quality may provide the first signal of response already within a month after treatment start.”

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Disclosures: This study was funded by Airsonett AB. Several authors report financial relationships with pharmaceutical companies, including Airsonett AB. For a full list of author disclosures, please see the reference.


Bjermer L, Eriksson G, Radner F, Peterson S, Warner JO. Time to onset of improvements in quality of life from temperature-controlled Laminar Airflow (TLA) in severe allergic asthma.  Respir Med. 2019;147:19-25.