Recruiting

HEPA Air Cleaner

Sponsor:

University of Washington

Code:

NCT07047430

Conditions

Pediatric Asthma

Eligibility Criteria

Sex: All

Age: 6 - 12

Healthy Volunteers: Not accepted

Interventions

Portable air cleaner with HEPA filter

Less effective portable air cleaner (no HEPA)

Study Details

Brief summary:

For children with asthma, exposure to indoor air pollution increases the risk of a serious asthma exacerbation, which can be life-threatening. Interventions aimed at improving indoor air quality, including use of a portable air cleaner with a high-efficiency particulate air (HEPA) filter, can reduce this risk, but the effectiveness, feasibility and acceptability of HEPA air cleaners varies by setting. In collaboration with a community health worker (CHW) delivered asthma education program, the investigators are conducting a randomized clinical trial to evaluate the effectiveness of HEPA air cleaners to improve indoor air quality and child asthma health in South King County of Washington state, a vulnerable community impacted by air pollution from airports and highway traffic. Key features of the Airports, Air Quality and Asthma (AAA) design include integration of CHWs into study procedures, including CHWs recruited from community-based organizations, into multiple aspects of the trial protocol. The investigators aim to recruit up to N=60 children with asthma randomized into intervention and control groups in a 1:1 ratio, conduct baseline assessments of indoor air quality and airway health, and collect repeated assessments of air quality and airway health during the three-month intervention period and after the trial concludes. Study findings will inform future approaches to integrate HEPA air cleaners into existing CHW asthma education programs in this and similar communities.

Conditions

Pediatric Asthma

Study ID

NCT07047430

Start date

Jun 1, 2024

Status verified date

Jun, 2025

Completion date

Jun 1, 2027

Anticipated

Primary completion date

Jun 1, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 6 - 12

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Child is 6-12 years old with a health care provider-diagnosed asthma.
  • Caregiver is comfortable in participating in all study activities in English (communicating with study staff by phone and completing online surveys).
  • Caregiver is familiar with the child's daily asthma health.
  • Residence within 10 miles of Seattle-Tacoma International Airport as determined by zip code
  • Child resides in caregiver's home at least five nights a week on a regular basis and has no plans to move in the next three months.

Exclusion Criteria:

  • Child has severe asthma at baseline. Severe asthma was defined in consultation with pediatric pulmonologists to be caregiver-reported asthma symptoms every day over the past 14 days and/or two or more inpatient hospitalizations for asthma in the past 12 months.
  • Households were excluded if there were multiple individuals within the same household with asthma eligible for the King County CHW Asthma Program or had severe asthma.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Supportive Care

Interventions and Outcome Measures

Arms

experimental: Effective portable air cleaner (HEPA)

During the baseline home visit, a Winix 9800 air cleaner is installed in the child's bedroom and paired with data logging energy use monitor as well as air quality monitor. Households randomized to the intervention group receive an air cleaner with a pre-filter, carbon filter, and with the HEPA air filter pre-installed.

sham comparator: Control portable air cleaner (less effective).

During the baseline home visit, a Winix 9800 air cleaner is installed in the child's bedroom. In the sham group, the Winix 9800 true HEPA filter and activated carbon filter which were removed via an internal modification not visible to the user. The air cleaner still included a washable fine mesh pre-filter that captures large airborne particles. Households randomized to the sham group receive an air cleaner with only the pre-filter and without the carbon filter, and HEPA air filter.

Interventions

Portable air cleaner with HEPA filter

The Winix 9800 is a true HEPA air cleaner that has been AHAM (Association of Home Appliance Manufacturers) Verifide® for rooms that are 500 square feet in size. The air cleaner has a washable fine mesh pre-filter that captures large airborne particles, an activated carbon filter that reduces volatile organic compounds and odors, and a true HEPA filter that captures 99.99% of airborne allergens as small as 0.003 microns in size.

Less effective portable air cleaner (no HEPA)

Winix 9800 air cleaner, with data logging energy use monitor is installed in the child's bedroom. In the sham group, the Winix 9800 true HEPA filter and activated carbon filter were removed. This was an internal modification and not visible to the user. The air cleaner still included a washable fine mesh pre-filter that captures large airborne particles.

Primary outcome measure

  • Symptom days over 7 days [ Time Frame: Repeated measure, assessed on a weekly basis throughout the 3 month observation period. ]
  • Change in Asthma Control Score [ Time Frame: From the baseline visit until the end of study follow-up, 3 months later. ]

Central Contacts and Locations

Central contacts

Christine Loftus, PhD, MPH

206-753-9079cloftus@uw.edu

Locations

University of Washington

Recruiting

Seattle, Washington, United States, 98195

Contacts

Elena Austin, ScD

206-221-6301elaustin@uw.edu

Maria Tchong-French

206-685-0465mtchong@uw.edu

Principal Investigator:

Elena Austin, ScD

More Information

Sponsor

University of Washington

Last update posted

Jul 2, 2025

Last verified

Jun, 2025

Keywords

  • air quality
  • indoor air
  • portable air cleaner
  • pediatric asthma
  • community health workers

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Washington on 2025-07-02.