The Efficacy of the Dyson Air Purifier in Improving Asthma Control: Protocol for a Single-Center, Investigator-Led, Randomized, Double-Blind, Placebo-Controlled Trial
Bibliographic record
Abstract
BACKGROUND: Indoor air quality has been shown to influence asthma control and outcomes. Air purifiers and high-efficiency particulate air filtration devices can improve indoor air quality by reducing the indoor levels of air pollution and allergens. However, the influence of this improved indoor air quality on asthma control remains unclear; hence, randomized controlled trials are needed to further elucidate this phenomenon. OBJECTIVE: This study aims to investigate the effect of reducing the levels of allergens and pollutants in the bedroom and living room through the use of Dyson air purifiers (Dyson Pure Cool) on asthma control. METHODS: This is an 18-month long, investigator-led, randomized, double-blinded, placebo-controlled, single-center trial. Subjects will be randomized in a 1:1 ratio to active or placebo Dyson filters. The primary outcome is the change in the scores of Asthma Control Questionnaire 6 and Asthma-specific Quality of Life Questionnaire from baseline. Secondary outcomes include changes in lung function (forced expiratory volume in one second, forced expiratory volume in one second/forced vital capacity ratio, and midexpiratory flows), peak expiratory flow measurements, airway hyperresponsiveness (assessed by methacholine bronchial challenge), fractional exhaled nitric oxide, and indoor air pollutant levels. The sample size will be 50 subjects, and all subjects will have a confirmed diagnosis of mild persistent to moderate persistent asthma along with an Asthma Control Questionnaire 6 score of >1.5. RESULTS: This study was approved by the West Midlands Research Ethics Committee (18/WM/0277). The study results will be published in peer-reviewed scientific journals; presented at relevant scientific conferences; and shared in plain English with participants in our newsletters, in our clinics, and via the David Hide Asthma and Allergy Research Centre website. Our trial began in September 2019 and is expected to end in August 2021. CONCLUSIONS: This is a double-blinded, placebo-controlled, randomized, investigator-led study to investigate the efficacy of a novel air purifier in improving asthma control in adults. The trial period of 18 months will facilitate the collection of robust data and will therefore generate clear signals. However, this extended trial duration may lead to patient withdrawal. Furthermore, this trial is conducted at a single center and in a location with a homogenous cohort of people, which may affect translatability. Nonetheless, it is hoped that the findings of this trial may help further inform clinicians regarding the utility of this novel device as an adjunct in asthma care. TRIAL REGISTRATION: ClinicalTrials.gov NCT04729530; https://clinicaltrials.gov/ct2/show/NCT04729530. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/28624.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.025 | 0.023 |
| Meta-epidemiology (narrow) | 0.007 | 0.003 |
| Meta-epidemiology (broad) | 0.015 | 0.005 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.003 | 0.004 |
| Scholarly communication | 0.004 | 0.004 |
| Open science | 0.004 | 0.002 |
| Research integrity | 0.009 | 0.008 |
| Insufficient payload (model declined to judge) | 0.048 | 0.010 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".