Air Filters for Childhood Asthma

(DAISY Trial)

Overseen By Anjum Hajat, PhD, MPH

Age: < 18

Sex: Any

Trial Phase: Academic

Sponsor: University of Washington

Disqualifiers: Unstable housing, Shared custody

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

Duration: 4 weeks

80 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether box fans with special filters can help children with asthma breathe easier by improving indoor air quality. The researchers aim to determine if these filters can reduce asthma symptoms and improve FEV1 (forced expiratory volume in one second), a measure of lung function. Children with asthma living in Seattle's Duwamish Valley, who frequently experience symptoms or often need rescue medication, might be suitable for this study. Participants will use a fan with either a high-quality filter (MERV 13 filter) or a basic one (Sham filter), track their breathing, and keep an air monitor at home. As an unphased trial, this study offers a unique opportunity to contribute to research that could enhance asthma management for children.

Do I need to stop my current medications for this trial?

The trial information does not specify whether you need to stop taking your current medications. It seems likely that you can continue your asthma medications, but it's best to confirm with the trial organizers.

What prior data suggests that these air filters are safe for children with asthma?

Research shows that MERV 13 filters can improve air quality by capturing small particles, potentially aiding asthma control. In past studies, these filters have reduced exposure to air pollution in schools and homes. MERV 13 filters are designed to catch particles as small as 0.3 microns, often linked to asthma symptoms.

While specific safety data for children using these filters is lacking, they are generally considered safe. The filters trap particles without releasing harmful substances. This trial is likely observational, examining outcomes without testing a new drug, so safety concerns are minimal due to the use of well-known air filtration technology.

In contrast, sham filters are designed to catch only large particles like lint and hair. They are not expected to help with asthma symptoms but are also considered safe. Participants will mainly notice differences in air quality between the two types of filters. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about these air filters because they offer a non-drug approach to managing childhood asthma, which is typically managed with inhalers and medications. The MERV 13 filter is particularly impressive because it can trap particles as small as 1 micron, which are often found in indoor air and can trigger asthma symptoms. Unlike standard asthma medications, which aim to control symptoms after they start, these filters work proactively by cleaning the air and potentially reducing the frequency and severity of asthma attacks. This method could provide a complementary strategy to traditional treatments, focusing on prevention and improving overall indoor air quality for children with asthma.

What evidence suggests that using box fans with MERV 13 filters could be effective for childhood asthma?

Research shows that MERV 13 filters, one of the treatments in this trial, can help reduce indoor air pollution, often a trigger for asthma symptoms. Studies have found that these filters capture most small particles, even those as tiny as 0.3 microns, which can irritate the lungs. By reducing indoor pollutants, these filters can noticeably decrease asthma symptoms in children. Evidence suggests that using these filters at home can lower asthma-related issues by up to 16%. The data supports the idea that improving indoor air quality with high-efficiency filters can lead to better asthma outcomes. Participants in this trial may receive either the MERV 13 filter or a sham filter, which serves as a control and only filters very large particles. ^{2 6 7 8 9}

Who Is on the Research Team?

Anjum Hajat, PhD, MPH

Principal Investigator

University of Washington

Are You a Good Fit for This Trial?

This trial is for children aged 6-17 with asthma in the Duwamish Valley. They must be able to fill out questionnaires, use a peak flow meter, and have an air monitor at home. Details on specific inclusion or exclusion criteria are not provided.

Inclusion Criteria

I am between 6 and 17 years old.

My asthma symptoms have been frequent and severe recently.

Living in Georgetown and South Park neighborhoods of Seattle

Exclusion Criteria

Children with unstable housing or shared custody arrangements

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Pre-intervention

Participants complete baseline assessments and two weeks of pre-intervention monitoring

2 weeks

1 visit (in-person)

Treatment

Participants use box fans with either sham or MERV 13 filters for four weeks

4 weeks

Weekly monitoring (virtual)

Follow-up

Participants are monitored for safety and effectiveness after treatment

6 months

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• MERV 13 filter
• Sham filter

Trial Overview The study tests if box fans with MERV 13 filters versus sham (fake) filters can lessen asthma symptoms and improve lung function (FEV1) in asthmatic children by comparing indoor air quality and health outcomes between the two groups.

How Is the Trial Designed?

Group I: Sham filter Experimental Treatment 1 Intervention

Participants in this arm will receive a sham filter for their box fans. These filters receive a MERV rating of 1 and only filter very large particles and debris such as lint, hair and insects. These particles have little to no impact on asthma symptoms. MERV stands for "minimum efficiency reporting value" and a filter receives a MERV rating as determined by the American Society of Heating, Refrigeration, and Air-Conditioning Engineers.

Group II: MERV 13 filter Experimental Treatment 1 Intervention

Participants in this arm will receive a MERV 13 filter for their box fans. MERV 13 filters trap the majority of small particles, as small as 1 micron. It also traps up to 75% of particles that are as small as 0.3 microns.

MERV 13 filter is already approved in United States for the following indications:

Approved in United States as MERV 13 filter for:

• Improving indoor air quality
• Reducing asthma symptoms

Who Is Running the Clinical Trial?

University of Washington

Lead Sponsor

Trials

1,858

Recruited

2,023,000+

National Institute of Environmental Health Sciences (NIEHS)

Collaborator

Trials

294

Recruited

1,233,000+

Published Research Related to This Trial

Children with asthma participating in placebo-controlled trials (PCTs) experienced higher rates of withdrawal due to asthma exacerbations (9.4%) compared to other trials (3.1%), indicating potential harm from not receiving necessary anti-inflammatory medications.

The study highlights that many PCTs did not require adequate treatment for children with more than mild asthma, exposing them to unnecessary risks without providing specific benefits or analyses for this age group.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ethical assessment of clinical asthma trials including children subjects. Coffey, MJ., Wilfond, B., Ross, LF.[2019]

In a study involving 12 young asthmatics allergic to house dust, the use of dust control measures, including electrostatic and high-efficiency particulate air filters, did not lead to significant improvements in asthma symptoms or peak expiratory flow rates.

The findings suggest that house dust suppression may not provide additional benefits for managing asthma in patients who are already well-controlled, indicating that other treatment strategies may be more effective.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

House dust control and asthma: a placebo-control trial of cleaning air filtration. Bowler, SD., Mitchell, CA., Miles, J.[2006]

Inhaled corticosteroids are the most effective treatment for controlling airway inflammation in children with persistent asthma, despite concerns about potential growth suppression.

Leukotriene receptor antagonists and long-acting beta2-agonists can help reduce the required doses of inhaled corticosteroids, and allergen immunotherapy is gaining recognition as an important treatment option.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prevention of asthma morbidity: recent advances. Zorc, JJ., Pawlowski, NA.[2019]

A study involving 40 children with moderate to severe asthma showed significant improvements in their peak flow meter (PFM) and metered-dose inhaler (MDI) techniques after attending an asthma camp, with PFM scores increasing from 6.0 to 8.9 and MDI scores from 4.1 to 6.5.

The camp led to a dramatic reduction in health care utilization, including a 59% decrease in emergency room visits and an 83% decrease in hospitalizations, along with a reduction in school absenteeism, resulting in an average health care savings of $2014 per child.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Outcomes analysis of a summer asthma camp. Kelly, CS., Shield, SW., Gowen, MA., et al.[2019]

The meta-analysis of asthma drug therapy trials revealed a small but measurable placebo effect in stable asthmatic patients, with a mean increase in forced expiratory volume in 1 second (FEV1) of 0.11 L/min and a 4.81% increase, indicating that some patients may experience improvements even without active treatment.

Interestingly, while the placebo group showed a slight increase in FEV1, they experienced a decrease in peak expiratory flow (PEF) by 2.24 L/min, suggesting that different measures of lung function can respond differently to placebo, highlighting the complexity of asthma treatment outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The placebo effect in asthma drug therapy trials: a meta-analysis. Joyce, DP., Jackevicius, C., Chapman, KR., et al.[2019]

In a study involving 89 households with children suffering from asthma, HEPA air filters were used significantly more during intensive monitoring periods (70% usage) compared to non-intensive periods (34% usage), indicating that active engagement is crucial for maintaining filter use.

Despite participants recognizing the benefits of HEPA filters for respiratory health, actual usage dropped significantly when not monitored, suggesting that simply providing filters is not enough; ongoing support and evaluation are necessary to ensure effective use and accurate assessment of health outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Use of Free-standing Filters in an Asthma Intervention Study. Batterman, S., Du, L., Parker, E., et al.[2021]

In a study involving 126 low-income households with children suffering from asthma, the use of free-standing HEPA filters significantly reduced particulate matter (PM) levels in bedrooms by an average of 50%, demonstrating their effectiveness in improving indoor air quality.

However, the effectiveness of these filters was highly dependent on how consistently they were used by the households, with usage declining over time, indicating that strategies to encourage ongoing use are essential for maximizing their benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners. Batterman, S., Du, L., Mentz, G., et al.[2022]

Asthma treatment in children should be flexible and adjusted every 3 to 6 months based on clinical and functional control, allowing for a step down in therapy when the condition is stable.

If asthma control is poor, it is crucial to assess treatment compliance and identify aggravating factors, with the primary strategy being to increase inhaled corticosteroid dosage and consider adding other medications like long-acting beta 2 agonists or leukotriene antagonists.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[When and how to modify the management of asthma in children over the age of 4]. de Blic, J., Deschildre, A., Pin, I., et al.[2019]

In treating childhood asthma, it's crucial to balance the effectiveness of medications like albuterol (a fast-acting bronchodilator) and inhaled corticosteroids with their potential side effects, as children may experience adverse events more severely than adults.

Inhaled corticosteroids are recommended as effective and well-tolerated first-line treatments, while other bronchodilators and anti-inflammatory agents can be used as needed, always considering the risk versus benefit of each medication.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of bronchodilator therapy in pediatric asthma patients. Selcow, JE.[2005]

In a study of 24 dust mite-sensitive asthmatic children, using Allergy Control Covers (ACC) significantly reduced dust mite allergen levels in mattresses after 1 and 2 months, while HEPA filters and control groups showed no decrease.

Only the ACC group demonstrated significant improvements in lung function (FEV1) and reduced peak expiratory flow rates after 4 months, indicating that while ACC may help with asthma control, the benefits may not be long-lasting.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An evaluation of mattress encasings and high efficiency particulate filters on asthma control in the tropics. Thiam, DG., Tim, CF., Hoon, LS., et al.[2016]

Anti-asthma medications alone are insufficient for effective asthma management, as they do not significantly reduce asthma mortality and can cause side effects.

Minimizing exposure to environmental allergens, such as house dust mites and cockroach allergens, is crucial in managing asthma, especially in children, as it can reduce the severity of attacks and the need for medication.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The non-drug treatment of asthma. Liang, AY.[2015]

Children have the highest rates of asthma, with nearly 5 million outpatient visits for asthma treatment in the U.S. in 2001, highlighting the need for effective therapies tailored for this age group.

Recent advancements in asthma treatments for children include new inhaled corticosteroids, long-acting beta2-agonists, leukotriene-receptor blockers, and a short-acting beta2-agonist, which could improve patient outcomes and reduce healthcare burdens.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Advances in the management of pediatric asthma: a review of recent FDA drug approvals and label updates. Kemp, JP.[2006]

A three-month asthma education program for 30 children and their parents significantly improved asthma control, leading to fewer daytime symptoms, night awakenings, and reduced reliance on rescue inhalers.

The program also resulted in a notable decrease in emergency department visits and hospitalizations, along with enhanced lung function and quality of life for the participants.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Asthma education and its impact on pediatric asthma severity: a prospective cohort study. Omara, HA., Mansour, MG., Badr, RM.[2023]

In a study involving 13 asthmatic children, the use of a portable laminar air-flow filter (Enviracaire) led to a statistical improvement in asthma symptom scores, indicating potential benefits for managing asthma symptoms indoors.

Despite the improvement in symptom scores, there was no significant change in peak flow measurements, suggesting that while the filter may help reduce symptoms, it may not directly enhance lung function.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Use of laminar air flow portable filter in asthmatic children. Villaveces, JW., Rosengren, H., Evans, J.[2007]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3165134/

Effectiveness of Air Filters and Air Cleaners in Allergic ... WHF with high-efficiency HVAC filtration is shown to be more effective in particulate reduction than individual HEPA PRACs. One study combining HVAC maintenance ...

2. withpower.com withpower.com/trial/phase-asthma-in-children-6-2024-28709

Air Filters for Childhood Asthma (DAISY Trial) The MERV 13 filter treatment is unique because it focuses on improving indoor air quality by reducing particulate matter, which can trigger asthma symptoms, ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4133967/

Reducing patients' exposures to asthma and allergy triggers in ... Use of a MERV12 or higher performing air filter in home ventilation systems can effectively reduce indoor levels of these common asthma and allergy triggers.

4. ww2.arb.ca.gov ww2.arb.ca.gov/sites/default/files/classic/research/apr/past/11-324.pdf

FINAL REPORT BENEFITS OF HIGH EFFICIENCY ... ... FILTRATION TO CHILDREN WITH. ASTHMA ... effectiveness of high efficiency air filtration in reducing indoor exposures and asthma symptoms.

5. cohse.umich.edu cohse.umich.edu/publication/effectiveness-of-using-enhanced-filters-in-schools-and-homes-to-reduce-indoor-exposures-to-pm2-5-from-outdoor-sources-and-subsequent-health-benefits-for-children-with-asthma/

Effectiveness of Using Enhanced Filters in Schools and ... In homes, using efficient furnace filters or air cleaners yields 11 to 16% reductions in the asthma burden with an annualized marginal costs of ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT07196436

Asthma Intervention With Residential Ventilation and Air ... ERVs will be equipped with minimum efficiency reporting value (MERV) 13 filters to capture particulate matter from incoming outdoor air, while sham/placebo ERVs ...

7. ww2.arb.ca.gov ww2.arb.ca.gov/sites/default/files/2025-03/II.2%20-%20DFR%2020RD015%20-%20HIFIVE%20-%20Rev26Feb.pdf

HIFIVE - Health Impacts of Filtration ImproVements in ... The goal of this study was to provide data on the benefits of improved air filtration in elementary schools via the use of standalone High- ...

8. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11134058/

Effectiveness of Asthma Home Management Manual and Low ... We aimed to investigate the effectiveness of an asthma home management manual and low-cost air filter in improving resource-limited settings.

9. nature.com nature.com/articles/s41370-025-00743-9

Classroom air quality in a randomized crossover trial with ... We assessed whether adding HEPA filter air cleaners to classrooms with existing HVAC systems reduces indoor air pollution exposure.