Clinical Trial of Air Cleaners to Improve Indoor Air Quality and COPD Health

NCT ID: NCT02236858

Last Updated: 2021-09-14

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 142 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2014-03-31
• Study Completion Date: 2021-09-10

Brief Summary

Objectives (include all primary and secondary objectives)

Specific Aim #1: To determine whether an air cleaner intervention to improve home air quality will improve respiratory symptoms, quality of life, lung function and reduce risk of exacerbations in former smokers with COPD.

Hypothesis: An intervention using high-efficiency particulate air (HEPA) and carbon filter air cleaners in homes of former smokers with COPD will improve respiratory symptoms, quality of life, and lung function and reduce risk of COPD exacerbations compared with placebo (sham air cleaners).

Specific Aim #2: To determine whether an air cleaner intervention to improve home air quality will be associated with intermediate outcome measures known to be linked with long term outcomes in COPD, including airway and systemic markers of inflammation and oxidative stress, in former smokers with COPD.

Hypothesis 2: An intervention using HEPA and carbon filter air cleaners in homes of formers smokers with COPD will be associated with lower levels of markers of inflammation and oxidative stress known to be associated with adverse outcomes in patients with COPD.

Detailed Description

This research is being done to learn whether an air cleaner intervention to improve home air quality (particulate matter (PM) and nitrogen dioxide (NO2) reduction) will improve respiratory symptoms, quality of life, lung function, and reduce risk of exacerbations in former smokers with COPD.

The investigators will place air pollution monitors in the home to measure the air quality over five 1-week periods (at 3 month and 1 week pre-intervention, and 1 week, 3 months and 6 months post-intervention). During each week of monitoring, the investigators will ask that a diary be kept of breathing and how the participants are feeling every day.

Participant will have 5 home visits and 5 clinic visits and monthly telephone calls during this time to see how the participant is feeling. One week after each home visit, the monitoring equipment will be picked up. After the 2nd monitoring period, active or sham air cleaners will be placed in home.

Conditions

Chronic Obstructive Pulmonary Disease (COPD)

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: OTHER
• Blinding Strategy: TRIPLE

Study Groups

Sham HEPA Air Cleaner

Sham HEPA Air Cleaner and Delayed Intervention. Homes in the control group will receive sham air cleaners that have the internal HEPA and carbon filters removed, but which will run normally, including similar noise, airflow and overall appearance compared to active air cleaners, thus blinding participants to filter status.

Group Type: SHAM_COMPARATOR

Sham HEPA Air Cleaner

Intervention Type: DEVICE

Homes in the control group will receive sham air cleaners that have the internal HEPA and carbon filters removed, but which will run normally, including similar noise, airflow and overall appearance compared to active air cleaners, thus blinding participants to filter status.

HEPA Air Cleaner

HEPA Air Cleaner also containing carbon filters (Austin HealthMate HM400) and capable of removing PM and NO2 will be placed in the bedroom and room where the participant reports spending the most time. These air cleaners are suitably sized to provide clean air delivery rates for the rooms in which they will be placed. Participants will be instructed to run the air cleaners continually during the course of the study and the units will be modified to prevent them from being turned off by the participants.

Group Type: ACTIVE_COMPARATOR

HEPA Air Cleaner

Intervention Type: DEVICE

Air cleaners containing HEPA and carbon filters (Austin HealthMate HM400) and capable of removing PM and NO2 will be placed in the bedroom and room where the participant reports spending the most time.

Interventions

HEPA Air Cleaner

Air cleaners containing HEPA and carbon filters (Austin HealthMate HM400) and capable of removing PM and NO2 will be placed in the bedroom and room where the participant reports spending the most time.

Intervention Type: DEVICE

Sham HEPA Air Cleaner

Homes in the control group will receive sham air cleaners that have the internal HEPA and carbon filters removed, but which will run normally, including similar noise, airflow and overall appearance compared to active air cleaners, thus blinding participants to filter status.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Age ≥ 40 years,
• Physician diagnosis of COPD,
• Global Initiative for Obstructive Lung Disease (GOLD) Stage II-IV disease with Forced Expiratory Volume (FEV1)/ Forced Vital Capacity (FVC) ≤70% and FEV1 (% predicted) <80%,
• Tobacco exposure ≥ 10 pack-years, and
• Former smoker. We will employ a combination of self-report and a biochemical marker to identify former-smokers. Exhaled CO (eCO) will be used as a marker of smoking status, as it is easy to perform, provides immediate data and is non-invasive. Former-smokers will be those who report no current smoking in the past 1 year AND have exhaled CO levels ≤ 6ppm. This threshold was chosen to maximize the chance of distinguishing true smokers and ex-smokers (>95%).

Exclusion Criteria

• Chronic systemic corticosteroids (≥ 3 months continuous use in past 12 months),
• Other chronic lung disease including asthma,
• Living in location other than home (e.g., long term care facility) and
• Home owner or home occupant planning to move or change residence within the study period.

• Minimum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Institute of Environmental Health Sciences (NIEHS)

NIH

Sponsor Role: collaborator

Johns Hopkins University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Nadia N Hansel, MD, MPH

Role: PRINCIPAL_INVESTIGATOR

Johns Hopkins University

Locations

Johns Hopkins University

Baltimore, Maryland, United States

Countries

United States

References

Woo H, Koehler K, Putcha N, Lorizio W, McCormack M, Peng R, Hansel NN. Principal stratification analysis to determine health benefit of indoor air pollution reduction in a randomized environmental intervention in COPD: Results from the CLEAN AIR study. Sci Total Environ. 2023 Apr 10;868:161573. doi: 10.1016/j.scitotenv.2023.161573. Epub 2023 Jan 18.

Reference Type: DERIVED

PMID: 36669663 (View on PubMed)

Other Identifiers

1R01ES022607

Identifier Type: NIH

Identifier Source: secondary_id

View Link

NA_00085617

Identifier Type: -

Identifier Source: org_study_id