Effects of HEPA filters in air purifiers on asthma control: A prospective, double-blind, multicenter, randomized clinical trial

Effects of HEPA filters in air purifiers on asthma control: A prospective, double-blind, multicenter, randomized clinical trial - Air purifiers and asthma control

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000061192

Enrollment

Registered

2026-04-08

Start date

2026-09-01

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

asthma

Interventions

(1) The group using air purifiers with HEPA filters (2) Intervention period: 3 months (3) Observation period: 1 month before the intervention period to assess indoor air quality without air purifie

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: (1) Details of drug therapy are not restricted. (2) One or more specific IgE antibodies must be positive.

Exclusion criteria

Exclusion criteria: (1) Patients cannot install air purifier at home because of this large size or other reasons. (2) Patients with cognitive impairment. (3) Patients with chronic pneumothorax. (4) Patients with unstable conditions due to a new pneumothorax occurring within the past 4 weeks. (5) Patients with unstable conditions due to asthma exacerbation or airway infection within the past 4 weeks. (6) Patients with pre-existing plans to be away from home for 7 days or more during the observation and intervention periods.

Design outcomes

Primary

Measure	Time frame
Difference in change in FEV1 between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters	—

Secondary

Measure	Time frame
(1) Difference in FVC change between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (2) Difference in ACT between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (3) Difference in CAAT between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (4) Difference in FeNO between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (5) Difference in change in allergens obtained from petri dishes placed in bedroom between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (6) Difference in change in allergens obtained from air purifier filters between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (7) Difference in microbial changes obtained from air purifier filters between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (8) Difference in microbial changes obtained from skin swabs between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (9) Differences in changes in air quality sensor data between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (10) Differences in changes in Th2-related inflammatory markers in blood tests between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (11) Differences in changes in air quality sensor data between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters due to differences in outdoor environmental data.	—

Measure

Time frame

(1) Difference in FVC change between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (2) Difference in ACT between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (3) Difference in CAAT between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (4) Difference in FeNO between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (5) Difference in change in allergens obtained from petri dishes placed in bedroom between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (6) Difference in change in allergens obtained from air purifier filters between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (7) Difference in microbial changes obtained from air purifier filters between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (8) Difference in microbial changes obtained from skin swabs between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (9) Differences in changes in air quality sensor data between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (10) Differences in changes in Th2-related inflammatory markers in blood tests between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters. (11) Differences in changes in air quality sensor data between patients using air purifiers with HEPA filters and those using air purifiers without HEPA filters due to differences in outdoor environmental data.

—

Countries

Japan

Contacts

Public ContactSatoshi Hamada

Graduate School of Medicine, Kyoto University Department of Advanced Medicine for Respiratory Failure

sh1124@kuhp.kyoto-u.ac.jp075-366-7689

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026