# 2/2 Multi-Center CLEAN AIR 2 Randomized Control Trial in COPD

> **NIH NIH U24** · JOHNS HOPKINS UNIVERSITY · 2024 · $644,625

## Abstract

PROJECT SUMMARY. COPD is a leading cause of death and morbidity worldwide and is attributable to the
aggregate burden of toxic gases and particles that individuals inhale during their lifetime. In the US, this exposure
is primarily cigarette smoke; however, even after smoking cessation, patients with COPD continue to suffer
respiratory morbidity. International 2022 COPD guidelines (GOLD) emphasize non-pharmacological
interventions to improve health, but few evidence-based interventions exist. The indoor environment is of
particular concern, as adults with COPD spend >90% of their time in the home. Particulate matter (PM) and
nitrogen dioxide (NO2) are common pollutants in indoor environments and lead to worse respiratory morbidity.
Our own study found that former smokers with COPD who have higher exposure to indoor pollutants have worse
respiratory-specific quality of life, symptoms, and a higher risk of respiratory exacerbations. Our group recently
completed a randomized controlled trial of 116 former smokers with COPD in Baltimore, MD (PI Hansel),
demonstrating that the placement of two portable air cleaners with high efficiency particulate air and carbon
filters can significantly reduce in-home PM and NO2 concentrations. In intention-to-treat analysis, there was a
trend toward better respiratory-specific quality of life, as measured by the St. George's Respiratory Questionnaire
(SGRQ) and statistically significant lower risk for moderate exacerbation, but not severe exacerbations, among
those who received the active air cleaner compared to sham. Further, per-protocol analysis suggested a dose-
response; among those who used the air cleaner at least 80% of the time, with a statistically significant
improvement in SGRQ. Despite encouraging results, the study did not meet its primary endpoint and was not
powered to determine whether air cleaner interventions can reduce moderate/severe exacerbations, including
acute health care utilization. Furthermore, the trial did not include strategies to increase adherence; and results
are limited to a small geographic area, limiting generalizability. The proposed study is a Phase III multi-center
randomized sham-controlled environmental trial to test the effectiveness of an air cleaner intervention targeting
indoor pollutants (PM and NO2) on quality of life and exacerbation risk reduction among former smokers with
COPD (n~770) across multiple clinical practice locations. We will conduct cost-effectiveness analysis to ensure
that study results address both clinical and economic efficacy to support policy decisions. We hypothesize that
the placement of two portable air cleaners with high efficiency particulate air and carbon filters can lead to
improved quality of life, reduced COPD exacerbation risk and reduced need for rescue medication use. Lastly,
we hypothesize that the use of portable air cleaners is cost-effective. The trial will provide a novel approach to
improve quality of life in these patients with...

## Key facts

- **NIH application ID:** 10920426
- **Project number:** 5U24HL169566-02
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Stephan Ehrhardt
- **Activity code:** U24 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $644,625
- **Award type:** 5
- **Project period:** 2023-09-10 → 2029-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10920426

## Citation

> US National Institutes of Health, RePORTER application 10920426, 2/2 Multi-Center CLEAN AIR 2 Randomized Control Trial in COPD (5U24HL169566-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10920426. Licensed CC0.

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